Vegetables & Fruit January/February 2021

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JANUARY • FEBRUARY 2021

Tomato production: it's all in the balance R40,00

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No 199

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ISSN 1015-85 37

Cover The annual tomato production is around 600 000 tonnes. There are three main types of tomatoes, namely round or fresh tomatoes, Roma tomatoes destined for processing, and cherry tomatoes.

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NEWS 4 New citrus export levy will see R1 billion invested 4 Drought and fire relief for farmers 5 Africa Agri Tech 2021 date change 5 Welcome to new PMA board members 6 Agriculture GDP still impressive 7 Memorandum to boost fruit exports 8 Project in Hoedspruit plants first lime trees 8 Rural hub business model to nurture small-scale farming 9 Various role-players collaborate to ensure pollinator safety

EDITORIAL Willie Louw (Group editor) Carien Daffue (Editor) 018 293 0622 info@mediakom.co.za PO BOX 20250, Noordbrug, 2522

TOMATOES 10

Tomato production: it's all in the balance

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NEWS

New citrus export levy will see R1 billion invested

The Citrus Growers’ Association of Southern Africa (CGA) welcomes the gazetting of the new statutory export citrus levy by the Minister of Agriculture, Land Reform and Rural Development, Thoko Didiza. The new levy will be funded by around 1 250 citrus growers over the next four years (from 2021 to 2024) and will ensure both the long-term competitiveness of the citrus industry as well as the sustainable growth of black citrus enterprises within the sector.

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CCORDING TO A statement by CGA, the new levy represents a 120% increase from the previous levy and will translate into an estimated R1 billion investment by local citrus growers into the sector over the next four years. The levy will continue to be administered by the CGA. A key funding area is ensuring greater transformation within the industry. 20% of the new levy will be allocated to the development of black citrus growers and their meaningful and lasting participation in the sector.

This funding will be invested in the CGA’s recently finalised four-year transformation plan (2021-2024), which will be implemented through the CGA Grower Development Company and the Citrus Academy.

With the citrus industry expected to increase its exports by over 500 000 tons over the next three to five years, investment in research and development is critical in order to ensure the sector remains competitive in overseas markets. For this reason, 60% of the new levy will be allocated to Citrus Research International (CRI) to provide research and technical services to growers. This is a pre-requisite for gaining,

retaining and optimising market access, which is a key priority for the industry over the short, medium and long-term.

One of the main blockages preventing increased market access is the stringent phytosanitary requirements effected by some countries. The new citrus levy will assist the CRI in enhancing the phytosanitary assistance it offers growers, including providing counterfoils for unjustified regulatory disruptions and changing regulations.

The remaining 20% of the new levy will be allocated to a number of other programmes, including working with government and other stakeholders to improve national transport infrastructure and logistics capacity, including the country’s rail and port operations.

The industry is expecting another record breaking export season in 2020, despite the challenges faced by the Covid-19 pandemic and national lockdown. The CGA is confident that the new levy will enable the industry to grow its market share even further and as a result, create even more jobs and bring in increased revenue for the country’s economy over the next four years.

Drought and fire relief for farmers Engen has stepped up to assist drought-stricken farming communities in Sutherland in the Eastern Cape as well as areas in the Free State that suffered damaging fire outbreaks in last year.

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HEY HAVE JOINED hands with longstanding customers, NGOs, AfriForum and NPO Beginet to ensure that farming communities most severely impacted, receive much needed aid and essentials such as food, toiletries, medication and clothing. They also donated diesel to the value of R20 000 to assist with the transportation of these essentials.

Drikus Kotze, Engen General Manager, Commercial, said they are proud to play a part in an initiative that helps alleviate the adversity of thousands of farmers and farm workers given the company’s close ties to the agricultural sector.

“Farmers in these areas were set to receive some relief aimed at ensuring that farms in the areas can remain in production,” commented Kotze.

“As a supplier of fuels and lubricants to the agricultural sector we have witnessed first-hand the impact that the fires and the on-going drought have had on farmers, farm workers and farming communities, which is why we have partnered with THT to assist the sector,” added Kotze.

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Engen assist drought-stricken farming communities in Sutherland in the Eastern Cape as well as areas in the Free State that suffered damaging fire outbreaks by joining hands with longstanding customers, NGOs, AfriForum and NPO Beginet.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

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Africa Agri Tech 2021 date change

UE TO COVID restrictions the second edition of Africa Agri Tech will be held on the following dates: Expo dates: Tuesday 22 – Thursday 24 June 2021.

Venue: Sun Arena, Time Square, Menlyn Maine, Pretoria.

The three-day conference programme will focus primarily

on profitability, the need to embrace technology and examining which technology to implement and economic impact.

The event is also extending to embrace women in agriculture, innovation start-ups and farming training and education workshops.

Welcome to new PMA board members JAN GREYLING Co-worker

Produce Marketing Association has elected several new industry leaders to the PMA Board of Directors.

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HE SIX NEWBIES ARE all industry specialists recognised in their fields of expertise. They have been welcomed by Cathy Burns, PMA CEO. “These industry leasers span the industry supply chain and the global community.” Burns mentioned that their voluntary skills and knowledge are essential to assist PMA in reaching our strategic goals and to realize our vision to grow a healthier world.

As board members they will be valued for “strategic guidance, thoughtful leadership and their unique perspectives to guide the growth of PMA and its value to members and the industry”. Burns added that it is a blessing to have the partnership and collaboration of the new board members in the years ahead.

The PMA board, consisting of industry leaders provide experience and an array of perspectives comprising the global produce and floral supply chains. PMA staff and industry stakeholders are working closely with the board to enhance member prosperity in finding industry solutions through shared connections and information.

PMA Board Chair for 2020/21 is Dwight Ferguson, President and CEO of the California Agricultural Leadership Foundation.

The newly elected members are: Alan Aguirre Ibarra who brings commercial and philanthropic experience. Ibarra is the current CEO of Grupo Alta and Divine Flavor LLC, an International grower/shipper company with 29 years of experience in the international produce sector. He is the president and founder of Fundación Alta IAP, president of the Hermosillo Food Bank, CEO of Distribuidora de Huevo de Baja California, and on the board of the Citi Banamex Group.

Amelie Aust is the Co-CEO and second-generation owner at Fall Creek, a blueberry breeding and nursery company serving berry companies throughout the Americas, EMEA and soon Asia. Since 2008 she helped to grow a family business into en enterprise with operations four continents. With

GROENTE & VRUGTE | JANUARIE • FEBRUARIE 2021

a master’s degree in Intellectual Property Law she also serves on the board of Global Women Fresh.

Nikki Cossio brings her recognition for building successful sustainability programmes and implementing innovative solutions to the board. She is founder and CEO of Measure to Improve. She is an industry educator, and visionary with numerous awards and recognition for leadership and innovation in sustainability. She is serving on PMA’s sustainability committee. Cossio founded the Monterey County Sustainability Working Group in 2011.

Amy L. Gates is proud of her leadership in streamlining and optimising operations and systems, creating new companies, and helping Frontera Produce of Edinburg, Texas to be a leader in traceability and food safety. She is former President of Frontera where she joined the produce industry in 2004.

Gates began her career with Famous Software and assisted with Frontera with its installation of the Enterprise Resource Planning software. She has served on the PTI Joint Industry Leadership Council since 2009.

Daniel Mathieson, CEO of Zespri, the grower-owned kiwifruit marketer focus on developing outstanding people and teams who are committed to delivering sustainable value for growers, consumers and stakeholders who support the healthy growth their business eco-system. During his more than 20 years at Zespri, Mathieson led Zespri’s sales and marketing operations and offshore markets in his role as Zespri’s President of Global Sales and Marketing. Earlier he worked for Omron and NEC in Tokyo.

Jim Richter is the President and CEO at Amerifresh in Scottsdale, Arizona. This business unit is strategic within US Foods.

Previously Richter worked at Wilcox Fresh on the grower-shipper side of the industry for 10 years. He held the position of CEO and was an owner-partner in Northeast Distribution Services. Richet spent 25 years at convenience stores at H.E.B., Marsh, Randalls-Tom Thumb, and at 7-Eleven in senior leadership roles. To date, for several years, he has served as a volunteer with the PMA Center for Growing Talent.

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NEWS

Agriculture GDP still impressive PAUL MAKUBE Senior Agricultural economist at FNB Agri-Business

South Africa’s agriculture GDP still came out impressive in the third quarter 2020 at 18,5% quarter-on-quarter seasonally adjusted annualised with a 0,6% point contribution, according to Statistics South Africa (StatsSA).

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GAIN, FIELD AND horticulture crops, as well as animal products came out strongly in contribution to agriculture growth. A combination of strong exports, higher commodity prices, and the huge summer crop harvest boosted revenues in the subsector. For example, total maize exports increased by 235% to 963 441 tons in the third quarter 2020 relative to the same period in 2019 and so far, 1,78 million tons have already been shipped for the current marketing season (May 2020 - April 2021) which is 159% higher year-on-year.

Horticulture crops also saw strong exports with the total agriculture export earnings rising by 5% year-on-year in the third quarter to US3,2 billion. After bucking the trend of seasonal declines during the winter period as well as the height of lockdown, livestock commodity prices remained resilient during the quarter and helped lift subsector performance thereby contributing positively to overall agriculture

third quarter 2020 GDP. With the new summer crop planting season and the harvest of the winter crops, FNB Agri-Business expected the 2020 agriculture performance to finish on a high note. The harvest estimates of the winter crops indicate a total record crop of 2,9 million tons, which is 46% up on 2019 levels. Wheat, the biggest winter crop, is estimated at up 40% year-on-year to 2,15 million tons which will help reduce the country’s import bill as it is a net importer.

On the back of a bullish weather outlook with the La Nina pattern having taken hold above 90% chance for Southern Africa, agriculture’s outlook for the year ahead is even more positive. The preliminary intentions to plant report for summer crops indicates a 5% increase in planted area for the 2020/21 season to 4,15 million hectares. This is likely to increase further in subsequent reports given the high commodity prices and better production conditions.

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Koringfokus / Wheat Focus: Die spesialistydskrif vir kleingraan in Suid-Afrika Vegetables & Fruit / Groente & Vrugte: Ontgin alternatiewe moontlikhede in nismarkte Subtrop Journal: Joernaal vir avokado-, mango- en lietsjiekwekers Navorsingsjoernale: SA Avokadokwekersvereniging, SA Mangokwekersvereniging, SA Makadamiakwekersvereniging en SA Lietsjiekwekersvereniging

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Memorandum to boost fruit exports Fruit exports from South Africa and China are set to get a major boost with the recent signing of a memorandum of understanding (MOU) between the two countries.

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HE SOUTH AFRICAN fresh fruit industry is the country’s largest exporter of agricultural products employing over 260 000 workers and supporting 1 million livelihoods.

Last year, South Africa exported over 2,8 million tons of fresh fruit to overseas markets. However, only a small percentage of these exports went to China. With a population of around 1,38 billion and the demand for fresh fruit expected to continue growing over the next few years, China offers a major opportunity for further market expansion. As a result, the local industry aims to increase its exports to China over the next five years and in this way contribute towards increased jobs in the sector.

The MOU, which was signed between Xiaohu Xu, Vice President of the China Chamber of Commerce of Import and Export of Foodstuffs and Native Produce (CFNA) and Justin Chadwick, Chairman of the Board of Fruit South Africa (Fruit SA) will contribute towards this objective, as it will serve to promote greater cooperation and statistical information exchange between the countries’ fresh fruit industries.

To this end, Fruit SA and CCCFNA will: • Support trade visits between South Africa and China for the representatives of each association.

• Cooperate in the areas of technology exchange.

• Promote information exchange on matters of relevance such as statistics of fruit exports and imports between the two countries, changes in regulatory legislation, and customs procedures.

• Support each other’s publicity and promotional activities, where appropriate.

The two associations will also nominate a working group to review the effective execution of commitments in the MOU, which is effective from the date of its signing. The

GROENTE & VRUGTE | JANUARIE • FEBRUARIE 2021

Justin Chadwick, Chairperson of Fruit SA, and Vangile Titi-Msumza, Vice-Chair of Fruit SA.

group will comprise at least one representative from each association and will monitor the implementation of projects and address any issues that may arise from the agreement.

The China Chamber of Commerce of Import and Export of Foodstuffs and Native Produce represent over 6 800 companies across China. These comprise some of the largest agricultural companies in the country as well a large number of small and medium small enterprises. With 44 chambers of commodities, all of which have a nation-wide membership, the CFNA represents all agricultural, forestry, food and farm products.

Fruit South Africa is a non-profit company and the umbrella body representing the Citrus Growers' Association of Southern Africa, the South African Table Grape Industry, Hortgro, the Fresh Producers’ Exporter Forum and the South African Subtropical Growers’ Association.

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NEWS

Project in Hoedspruit plants first lime trees

The Moletele Community, Komati Fruit Group and international beer company ABInBev recently celebrated a momentous occasion. The first lime trees were planted at the Moletele Limes project sponsored by AbInBev. Each of the participating groups – AbInBev, Komati Fruit Group, Moletele CPA and department of Agriculture, Land Reform and Rural Development – planted a tree during a ceremony.

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HE MOLETELE CPA in Hoedspruit is the owner of the farm Richmond in the Hoedspruit district. The farm is leased to Richmond Kopano Farming (Pty) Ltd, a subsidiary of the Komati Group. A portion of 60 ha is leased to Moletele Limes (Pty) Ltd. The shareholders in Moletele Limes are Moletele CPA (51%) and Komati Group (49%).

Komati Group has successfully negotiated a subsidy with AbInBev for the establishment of a lime project where limes will be grown for 12 months of the year. Limes produced will be offered to AbInBev and the balance either exported or sold on the South African local market.

The limes trees will be kept in production by Komati Fruit Group. After two to three years the lime trees will be harvested and will be available to be used with the consumption of Corona Beer produced by AbInBev. By applying various innovative farming methods, the aim will be to produce and harvest limes throughout the year.

Piet Smit, CEO of Komati Fruit Group on the left, and Albert Thabane, Chairman of Moletele CPA on the far right, with the Moletele CPA Committee members during the tree planting ceremony.

Milaan Thalwitzer, Chairman of Komati Fruit Group Board; Albert Thabane, Chairman of Moletele CPA; and Josh Hamman, ABInBev Director Agricultural Development and Sustainability.

Rural hub business model to nurture small-scale farming Food insecurity, unemployment and skills shortfalls continue to plague rural areas across South Africa, but the franchise retailer SPAR is helping to close these gaps with its Rural Hub business initiative. The Rural Hub model forms part of the retailer’s drive to support and empower small-scale local farmers, create jobs and sustain local economies.

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IRST STARTED IN Mopani in the Limpopo province in 2017, with a dedicated packhouse established to buy the product direct from local farmers, future hubs are now being planned. Hectares planted, farmers trained and mentored, and people employed are all on the rise.

All the participating small-scale farmers receive the following support interventions: grants and loans, mentorship, market readiness, market access and leadership. All the participating small-scale farmers have been trained in financial management, land preparation, planting, integrated pest and disease management, fertilisation, irrigation and harvesting.

“To us, food safety is non-negotiable and we’re proud to report that all of our Mopani rural farmers achieved the LocalGAP Intermediate level in 2019 and will be GlobalGAP

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certified in 2020,” says SPAR Risk and Sustainability Executive, Kevin O’Brien. The Mopani Rural Hub packaging facility is, furthermore, assessed in accordance with the Global Food Safety Initiative (GFSI) and Global Markets Program.

“We are seeing some of our farmers becoming fully-fledged commercial farmers in their own right, as yields reach commercial farming quality thereby opening up more opportunities to sell their produce. We see that as a fantastic achievement,” he says. As an example, in 2020, the programme’s farmers supplied a range of products under the Freshline Brand for the first time.

A ringing endorsement of these achievements came when SPAR Rural Hub won the rural and township development award and the overall winner award at the Absa BusinessDay Supplier Development Awards.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

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Various role-players collaborate to ensure pollinator safety The crop protection industry, together with a number of grower and beekeeping associations, have committed to ensuring that their activities are conducted in such a way that pollinator safety is a key priority.

Pollination and the wellbeing of bees during their brief, yet vital sojourn in orchards, is critical to the pome and stone fruit industry.

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O THIS END, a pollinator charter was created in which all parties involved agreed that their members shall adhere to the guidelines provided in the charter. These parties include CropLife SA, Agri SA, Grain SA, SABIO, Hortgro, SAMAC, SANSOR, Subtrop, and Citrus Research International.

“Bees form such a critical component of biodiversity and food production that we owe them all the protection we can afford. By following label directives strictly, adhering to bee safeguarding protocols and establishing information networks between beekeepers and crop farmers, we can prevent pesticide impacts on bees. It needs a total commitment from the crop production, plant protection and beekeeping sectors to achieve this objective” says Dr Gerhard Verdoorn, operations and stewardship manager of CropLife SA, the association representing the crop protection industry.

The charter states that growers and the crop protection industry shall only recommend or apply crop protection products that are registered according to Act 36 of 1947, as prescribed by the label, and within an integrated pest management programme. In addition, they will ensure that measures are taken to minimise dust resulting from treated seed, and to avoid spraying when bees are foraging, unless absolutely necessary and only with products which are explicitly designed for bee-safe application during flowering.

Commenting on behalf of the macadamia industry, Schalk Schoeman, research extension manager at SAMAC says: “We acknowledge the importance of bees for the macadamia industry. Macadamia pollen is sticky and is not easily dispersed by wind. Clearly invertebrates and more particularly honeybees play an intrinsic role in dispersing pollen and should be regarded as very important allies in sustainable macadamia production. To further this, SAMAC is currently funding a number of projects focussing on honeybees and growers are actively discouraged from using products that may harm bees during or just after flowering. Environmental sustainability is a key aspect of macadamia farming in South Africa, therefore SAMAC proudly endorses the new pollinator charter.”

In addition to the macadamia industry, pollinators play a critical role in deciduous fruit, citrus, vineyards, canola and even sunflower production.

“Pollination and the wellbeing of bees during their brief, yet vital sojourn in orchards, is critical to the pome and stone fruit industry. The deciduous fruit industry is fully committed

GROENTE & VRUGTE | JANUARIE • FEBRUARIE 2021

Honeybees play an intrinsic role in dispersing pollen and should be regarded as very important allies in sustainable macadamia production.

Pollinators play a critical role in deciduous fruit, citrus, vineyards, canola and even sunflower production.

to the pollination charter and recognises the role of the grower in ensuring pollinator safety”, says Hugh Campbell, general manager of Hortgro Science.

Another key point is effective and timeous communication between growers and beekeepers. This is why the charter includes an undertaking from pollinators and bee farmers to formalise the relationship with the farmer or landowner, to communicate with growers and other pollinators about their intended activities, and to ensure good hive management practices.

This model of collaboration among multiple stakeholders is an important step in the right direction to highlight the responsibilities of all parties to ensure bee health.

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TOMATOES

Tomato production: it’s all in the balance SAKATA During the life cycle of tomato production, there are different stages that the plants go through and need to be managed or manipulated by the grower. This can be expressed as the generative or vegetative stages of the plant.

Wrong decisions made at the beginning of a crop can affect the crop throughout its production cycle.

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HE GROWING STAGES are influenced by different seasons and environmental conditions, such as warm dry or overcast rainy conditions, day / night cycles, temperature as well as day lengths, can also play a role in the productivity of the plants. What makes it more difficult is that the seasons during the last few years have changed and growers need to be aware of how this impacts the outcome of the crop.

Tomato plants grow and produce leaves and fruit, and should be managed to achieve a balance between them.

This can also be expressed as the source-sink ratio of the plant – where the fruit is typically the sink and the leaves the source. An imbalance in this ratio can have a negative impact, resulting in lower yields and quality or drastically reduce the length of the production cycle either by disease or exhausting the plant with too high fruit set in the beginning.

Overly vegetative plants with large leaves, thick stems and small weak trusses will not yield as well as a plant with a balanced growth habit. Plants that are too thin and with small leaves may not develop enough leaf area to produce the required sugars for maximum expansion of fruit, therefore leading to lower yields. Tomato plants producing 13 trusses with 5 fruit per truss, could produce 1,3 kg per plant more just by adding 20 g per fruit on average.

Optimal temperatures for the assimilation of sugar within the plant are between 23 and 25°C. As soon as temperatures vary outside of this range, the possibility of reduced fruit size and quality is a reality. Lower temperatures lead to slow colour-up and ripening. Higher temperatures lead to an increased rate of ripening that could cause blotchy ripening or shorter shelf life.

The management of the root zone is critical for the development of a healthy and productive plant often overlooked – “out of sight out of mind” as the saying goes.

Looking at the reasons for lower yields and quality, one is faced with the reality that a simple answer is seldom the solution to the question. Various reasons can be given, and depending on the angle from which it has been looked at, the answer may vary. Farmers, seed, chemical or fertilizer representatives can all give reasons for this, but it is ultimately the growers’ responsibility to look at all the factors, evaluate the growing conditions and look for possible answers.

The grower needs to empower himself to make economic decisions concerning sustained production – more is not always better.

In many parts of the world, growers make very informed decisions, when to stop with the crop or not. Growers would

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rather produce shorter crops with better fruit size and quality and will stop before the input cost starts to negatively impact the profit. The aim would be to record as much information as possible to empower the grower to avoid possible problems in the future and optimise production techniques for his or her farm.

Control strategies for various physiological defects leading to lower yields can be summarised by the following statements found in most tomato production guidelines: • Adequate potassium levels have shown to reduce the problem, but may not eliminate it. Balanced fertilizer and pH levels are important.

• Some varieties are more tolerant.

• Avoid any stress conditions in the growing season.

• Plan plantings to avoid unfavourable seasonal conditions.

• Control of relative humidity (not possible in a shade house or open field).

• Prevent excessive vegetative growth.

• Avoid excess of ammonia nitrogen.

• Proper water management and a good nutritional programme are important to prevent overly succulent or vegetative plants.

• Frequent picking.

• Limit fruit exposure to direct sunlight as exposed fruit are more susceptible.

• Proper pruning practices.

• Prevention of defoliation due to leaf diseases.

This is easier said than done, as every aspect of the growth of the plants needs attention, and seldom one aspect can be isolated as the single solution to the problem. Water, climatic, plant, soil and management factors all plays a big role in the success of the grower. The approach should therefore be of holistic approach looking at all the factors involved in plant growth and management.

Some of the factors involved are listed below, and it would be wise to rethink the approach to production giving thought to these.

• Water factors: Water availability, amount and time of irrigation, water quality.

• Climatic factors: Ambient temperature (day/night), solar radiation, wind speed, rainfall, humidity, day length, length of the growing season.

• Plant factors: Crop / variety, rooting characteristics, drought tolerance, growth stage, harvestable constituent, yield and quality, salt tolerance, nutrient requirements, stomatal

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

TAMATIES mechanism, canopy architecture.

• Soil factors: Soil structure, soil texture, soil depth, mechanical impedance, infiltration rate, drainage rate, soil aeration, water retention characteristics, water table, soil salinity, soil fertility, soil temperature, soil-borne organisms.

• Management factors: Date of planting, plant population, irrigation system, critical growth stages, fertilization, crop protection, cultivation, weed control.

• Light intensity received by a plant directly affects the number of photoassimilates available to the fruit, it also increases their sugar: acid ratio. It influences the transpiration rate and the water uptake by the plant, which in turn, affects the EC around the root. Keeping the proper levels and ratios between all the nutrients in the root environment, for each growth stage of a crop should be targeted to achieve high yields and quality products throughout the cropping season.

A statement like this is loaded with information that needs careful attention, addressing environment, plant physiology, water uptake, nutrition, soil or medium characteristics, crop season and cycle.

Only with a proper understanding of the factors above, can a grower know his crop and achieve a higher yield with better quality.

between the genetic potential of the seed, its physiological characteristics and the environment, including management, SAKATA give no warranty express or implied, for the performance of crops relative to the information given nor do SAKATA accept any liability for any loss, direct or consequential, that may arise from whatsoever cause. Please read the Sakata Seed Southern Africa (Pty) Ltd Conditions of Sale before ordering seed.

DISCLAIMER: This information is based on SAKATA’s observations and/or information from other sources. As crop performance depends on the interaction

The management of the root zone is critical for the development of a healthy and productive plant often overlooked.

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Sakata Quality Seed

SVTE8444*

Obus*

SVTH6995*

*Experimental: This variety does not appear on the current South African Variety list, but has been submitted for registration..

Tel: 011 548 2800 www.sakata.co.za e-mail: info.saf@sakata.eu

POTATOES

‘n Antwoord op die vraag van swambeheer SYNGENTA

Die verhouding tussen voedselsekerheid in die toekoms en al die netelige kwessies rondom chemiese plaagdoders is kompleks. Syngenta vertrou egter hul nuwe aktiewe bestanddeel kan ‘n uitblinker te wees.

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IE DRUK OP chemiese plaagdoders is besig om toe te neem. Afgesien van omgewingsveiligheid en regulatoriese vereistes, is die tyd en koste verbonde aan die ontwikkeling van nuwe chemiese mideel ‘n reuse uitdaging.

Volgens onlangse navorsing kos dit sowat $286 miljoen (ongeveer R4 230 miljard) om ‘n nuwe chemiese plaagdoder te ontwikkel, nagenoeg 55% meer as ‘n dekade gelede.

Met die toename in die wêreldbevolking word voedselproduksie al hoe belangriker. Die Wêreldgesondheidsorganisasie het reeds in 2018 gereken dat landbougrond wat nuut ontwikkel word in slegs sowat 20% van die verhoogde vraag na voedsel sal voorsien. Dit beteken gevolglik dat die meeste van die bykomende voedsel wat teen 2050 nodig gaan wees, op bestaande landbougrond geproduseer sal moet word. Dit kan slegs bereik word deur die ontwikkeling en gebruik van beter kultivars en plaagbeheer saam met doeltreffender plantvoeding en bestuurspraktyke.

Volgens Croplife International gaan tussen 26% en 40% van die wêreld se potensiële gewasproduksie verlore as gevolg van onkruide, peste en siektes. Hierdie verliese kan moontlik verdubbel indien plaagdoders nie gebruik word nie.

Intussen neem gevalle van weerstand vinnig toe, terwyl die bekendstelling van nuwe produkte oor die laaste paar jaar dramaties afgeneem het. In die 1990s is sowat 120 nuwe produkte bekendgestel. In die eerste 10 jaar van die nuwe eeu het dit afgeneem na net meer as 100 en van 2010 af tot 2018 was daar slegs 40 nuwe bekendstellings (McDougall, 2018).

Hierdie sameloop van omstandighede laat die landboubedryf met minder opsies om die toenemende hoeveelheid peste en plae te kan beheer en dit ry pogings om meer voedsel te produseer in die wiele. Boonop word Suid-Afrikaanse boere al hoe meer geknel deur die knyptang van stygende insetkoste en lae produkpryse.

Maar daar is goeie nuus. Syngenta het na sowat nege jaar se navorsing en ontwikkeling ‘n nuwe uitblinker bekend gestel. AdepidynTM is ‘n nuwe klas karboksamied met ‘n SDHI- (suksinaatdehidrogenase-inhibeerder) meganisme van werking en behoort tot die FRAC-groep 7 swamdoders.

Adepidyn word vinnig deur die waslaag van blare opgeneem waar dit ‘n reservoir vorm. Van daar word die aktiewe bestanddeel stadig in die blaarweefsel en xileem versprei.

Hoewel die xileem-sistemiese eienskappe van Adepidyn relatief stadig is, is die molekule besonder aktief en bied gevolglik effektiewe langerwerkende beheer.

12

Die eerste registrasie van ‘n produk wat Adepidyn bevat, Miravis® Duo, is aan die einde van 2019 goedgekeur en meer moontlikhede sal in die toekoms die lig sien.

Die doeltreffendheid van Miravis Duo is reeds sedert 2013 in Suid-Afrika getoets. Positiewe resultate in ongeveer 60 statistiese en demonstrasieproewe het daartoe gelei dat die produk op aartappels geregistreer is vir die langwerkende beheer van vroeë roes.

Afgesien van Adepidyn, bevat Miravis Duo ook difenokonasool. Hierdie kombinasie lewer nie net uitstekende beheer van vroeë roes nie, maar dra ook tot weerstandsbestuur by. Miravis Duo is binne een uur reënvas sodat ‘n ontydige bui reën of die nodigheid om te besproei, nie met doeltreffende plaagbeheer sal inmeng nie.

Produsente moet die produk as deel van ‘n voorkomende spuitprogram gebruik om vroeë roes op aartappels te beheer en te alle tye die etiket-aanbevelings volg.

Syngenta het volle vertroue in die wesenlike verskil wat Adepidyn in die Suid-Afrikaanse aartappelbedryf gaan maak en die positiewe uitwerking wat dit in die toekoms op ander gewasse gaan hê. Hierdie deurbraak is tekenend van Syngenta se slim-boer-filosofie in aksie, gemik daarop om waarde en gemoedsrus aan produsente te gee, produktiwiteit te verhoog en met voedselsekerheid te help.

Bronne http://news.agropages.com/News/NewsDetail---34017.htm https://www.who.int/news-room/fact-sheets/detail/pesticide-residues-in-food https://croplife.org/wp-content/uploads/2018/11/Phillips-McDougall-Evolution-of-the-Crop-Protection-Industry-since-1960-FINAL.pdf https://croplife.org/case-study/crop-protection-industry-supports-faoon-ipm/ Tipiese vroeë-roesletsel op aartappelblare (K Beyers, Syngenta) LEES DIE ETIKET VIR VOLLEDIGE BESONDERHEDE MIRAVIS® Duo bevat Adepidyn™ (pydiflumetofen) en difenokonasool (Reg. nr.

L10750, Wet 36 van 1947) SKADELIK. MIRAVIS® Duo is die geregistreerde handelsmerk van ’n Syngenta Groep Maatskappy.

Syngenta Suid-Afrika (Edms) Beperk, Privaatsak X60, Halfway House, 1685. Tel. 011 541 4000. www.syngenta.co.za © Syngenta Ag, 2000. Kopiereg van die dokument is voorbehou. Alle ongemagtigde vermeerdering word verbied.

MIRAVIS® bevat Adepidyn™ (pydiflumetofen) (Reg. nr. L10761, Wet 36 van 1947) SKADELIK. MIRAVIS® is die geregistreerde handelsmerk van ’n Syngenta Groep Maatskappy.

Syngenta Suid-Afrika (Edms) Beperk, Privaatsak X60, Halfway House, 1685. Tel. 011 541 4000. www.syngenta.co.za © Syngenta Ag, 2000. Kopiereg van die dokument is voorbehou. Alle ongemagtigde vermeerdering word verbied.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

the

stamina to beat

early blight

Two step simplicity: difenoconazole cleans up existing early blight infections while Adepidyn™ ensures continued protection afterwards.

Right place, right time: Slow systemic movement of Adepidyn™ through the leaf wax layer ensures powerful leaf protection, securing biomass capability for developing tubers.

Carboxamide technology, reinvented: Adepidyn™ is a new class carboxamide with a high affinity for leafwax layers, providing longer residual action and rain-fastness within 1 hour. Smart technology, whatever the weather.

Simple. Powerful. MIRAVIS® Duo.

READ THE PRODUCT LABEL FOR FULL DETAILS. MIRAVIS® Duo contains Adepidyn™ (pydiflumetofen) and difenoconazole (Reg. no. L10750, Act 36 of 1947) HARMFUL. MIRAVIS® Duo is a registered trademark of a Syngenta Group Company.

Syngenta South Africa (Pty) Limited, Private Bag X60, Halfway House, 1685. Tel. (011) 541 4000. © Syngenta Ag, 2000. Copyright of this document is reserved. All unauthorised reproduction is forbidden.

@SyngentaSA

POTATOES

New CEO for Potatoes SA Willie Jacobs took over the leadership of Potatoes SA (PSA) as Chief Executive Officer (CEO) after Dr André Jooste, who as part of his career planning left the organisation after nine years.

I

NITIATIVES ESTABLISHED by Dr Jooste are highly regarded and supported by industry. Under Dr Jooste’s leadership valuable research was done not only in terms of product, but also in terms of producer concern issues in specific areas.

According to PSA the potato industry is privileged for Jacobs to have accepted the position of CEO. The Board of Directors of PSA is confident that with his expertise and experience as agricultural economist, PSA will build and expand on the legacy of Dr Jooste.

Jacobs studied BSc Agricultural Economics at the University of the Free State and obtained an MBA at North West University.

Recently he worked on several contracts as an independent consultant.

Most of the contracts were agricultural funding and management related. Previously he worked as Executive at the Land Bank, serving corporate clients and later, as Executive Director of Obaro Financial Services, where farming activities were funded.

Jacobs considers the impressive legacy of Dr Jooste, during which he succeeded in breaking the ice, as aspects that in future will assist him in his new role, in particular with regards to the transformation financing agenda and

14

piloting some of the improved financing methodologies in the potato industry as well as liaison with government.

Where the difference comes in, from where Dr Jooste created a good foundation for entrance into the market and the direction that Jacobs will take, is to utilise the financial exposure he had to optimise the farming profit of potato producers and to place potatoes as product within the consumer environment on a new level.

For Jacobs it is important to have the ability to address the risk of everything that could affect the quality, volume and consumability of the product in order to support stability in the potato industry. The risk of the production of a specific cultivar lays in two areas, its quality and production volumes. For this reason, it is critical for PSA to continue to provide the research capacity, addressing these needs.

Jacobs concedes that with all these factors taken into consideration, the producer as marketer and business owner must understand all the factors that have an impact on their businesses by making informed decisions for them.

He hopes PSA and its members will expand the market space of potatoes to the extent that there will be room

for new entrees without impeding existing producers.

Jacobs sees his role in PSA as spearhead, with a sharp focus on the accuracy and relevance of the outputs of the organisation through a management style of involvement, participation, and facilitation. He trusts that each of the current staff of PSA, in his and her own right, is the best the market has to offer for their specific role, and he will find pride in bolstering that capacity.

Willie Jacobs, CEO Potatoes SA.

AARTAPPELS

Geïntegreerde gewasbestuursprogramme NEXUS

Vennootskappe met kenners en spesialiste, tesame met die nuutste tegnologie en behoorlike data-ontleding, is die sleutel tot 'n suksesvolle aartappel boerdery.

N

EXUSAG GEWASADVISEURS ondersteun produsente met doelgemaakte gewasbestuursprogramme, deur al die fases van dié produksiesiklus: vanaf grondvoorbereiding deur die plantperiode tot oes.

Voor planttyd, staan NexusAG se gewasadviseur produsente by met 'n reeks tegniese dienste en kundigheid om gesonde grond te vestig. 'n Doelgerigte grondvoorbereidingsprogram is van kardinale belang. Dit skep die optimale omstandighede vir nuwe gewasaanplantings.

Vanaf die plantperiode tot oes verskuif die fokus van gesonde grondvestiging na die bevordering van plantgesondheid. Dit behels plantvoeding- en oesbeskermingsprogramme wat die opbrengsmikpunt en die voorkoming van weerstand nastreef.

Tegniese dienste sluit grondkartering, grondmonsterneming, insek- en plaagbeheerprogramme, hommeltuig-data, plant- en kultivarseleksie, bemestingsbeplanning en ontleding-interpretasie in, om volhoubare en winsgewende boerderypraktyke te bevorder.

Kontak 'n NexusAG Croplife-geakkrediteerde gewasadviseur vir meer inligting. Skakel 021 860 8040 of besoek www.nexusag.net.

'n Doelgerigte grondvoorbereidingsprogram is van kardinale belang.

'n Aanplanting van gesonde aartappels.

15

GEÏNTEGREERDE GEWASBESTUURSPROGRAMME VIR VOLHOUBARE GROEI NEXUSAG GEÏNTEGREERDE GEWASBESTUURSPROGRAMME SLUIT DOELGEMAAKTE PLANTVOEDING- EN OESBESKERMINGSPROGRAMME IN WAT GESONDE GROND EN VOLHOUBARE VOEDSELPRODUKSIE BEVORDER!

ONS WIL SAAM MET JOU ’N LANG PAD LOOP! NexusAG geïntegreerde gewasbestuursprogramme kombineer data-analise en die nuutste landboutegnologie om gepaste plantvoeding- en plaagbeheerprogramme te ontwikkel.

Ons wetenskaplike benadering ondersteun ons produsente regdeur die produksiesiklus, vanaf plant tot oes.

TYDENS HIERDIE FASES verskuif die FOKUS vanaf VESTIGING IN GESONDE GROND, tot die bevordering van plant- en grondgesondheid en volhoubare effektiewe produksie, deur die gebruik van PRODUK-AANBEVELINGS en TEGNIESE DIENSTE SOOS:

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INSEK- EN PLAAGBEHEERPROGRAMME

BEROKING

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Kontak gerus u naaste NexusAG Croplife-geakkrediteerde gewasadviseur met navrae oor doelgemaakte aa appel-bestuursprogramme, wat u unieke omgewing en spesifieke omstandighede in ag neem, om volhoubare oplossings vir u boerdery te bied.

KONTAK ONS VIR MEER INLIGTING:

021-860 8040

www.nexusag.net

POTATOES

Awareness – potato spraing causing quarantine pests with confusing symptoms André Wessels POTATO CERTIFICATION SERVICE andre@potatocertfication.co.za

S

PRAING IS THE TERM used for a range of internal and external symptoms occurring in the potato tuber flesh, consisting of brown, necrotic rings, arcs and flecks or spots (Photo 1) (Fera Spraing Disease of Potato, 2020).

Two viruses which do not occur in South Africa can cause these symptoms, namely Tobacco Rattle Virus (TRV) and Potato Mop Top Virus (PMTV). Both these viruses are soil borne with similar symptoms but transmitted through different modes of transmission.

These viruses are of economic importance due to the presence of necrotic symptoms which may lead to downgrading or rejection of a seed lot and be unmarketable, especially if intended for processing.

Tobacco Rattle Virus (TRV) Tobacco Rattle Virus (TRV) is transmitted by free living nematodes, Trichodorus and Paratrichodorus spp., which are migratory root ectoparasites, also named stubby-root nematodes. When present in large populations, they may damage the potato, either directly by feeding on the root system thus causing necrosis or indirectly by transmission of TRV (Stent, 2011:115). In the presence of virus-carrying nematode populations, susceptible cultivars to TRV may show symptoms.

Adults and juveniles can transmit the virus when feeding on root cells and the virus can be retained for many months by non-feeding nematodes. Nematodes spread with surface water and favour light sandy soils, although TRV and its vector have been found in very diverse types of soil.

Symptoms on foliage Certain plants can be healthy when infected seed potatoes are planted but in certain varieties the virus infection may cause mottled and/or distorted leaves. Different forms of mosaic symptoms and mottling, turning into necrotic spots (Photo 2) may be observed on leaves on one or two stems per plant which grows less vigorously. Progeny from infected plants are smaller and misshapen, with yield being affected (Wale et al., 2011:86).

Symptoms on tubers In potatoes, TRV causes Corky Ringspot Disease (CRS), also known as Spraing. Symptom expression varies greatly and is affected by cultivar and environmental conditions (Wale et al., 2011:85). The most typical symptoms of TRV are usually found in the flesh of the tubers with brown necrotic arcs or corky spots sometimes extending over a large part of the tuber (Photo 3 and 4). Symptoms are not always visible on the

Photo 1: Spraing symptoms on TRV infected tubers. Source – Plant Management Network.

Photo 2: Potato leaf necrosis and chlorosis caused by TRV. Source Ephytia.

tuber surface, but superficial necrosis (Photo 5) can sometimes be found, which can form rings around the lenticels (Photo 6) which, when cut, are not always related to internal necrosis and they remain localised, more or less discontinuous, underneath the skin (Photo 7). Symptoms do not increase during storage.

Potato Mop Top Virus (PMTV) Potato Mop Top Virus (PMTV) is only known to be transmitted by the fungus Spongospora subterranea, the causal agent of powdery scab. PMTV is carried in the resting spores that can TO PAGE 18

16

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

Tindrum 20/129

Aartappelprodukte wat werk Die beproefde sukses van die Philagro produkreeks verseker dat ons produkte kop en skouers uitstaan in ‘n koste-doeltreffende aartappelprogram!

• Verbeter die uitloop van moere met ProGibb® 4% en ProGibb® 40 WG. Beheer: • Laatroes met Leimay® 200 SC – Nuwe eN uNieke chemie iN S.A. • Swartskurf en Stamkanker met Rizolex® WP • Afrika bolwurm, Aartappelmot en Tuta absoluta met SumiPleo® • Snywurms, Afrika bolwurm en Aartappelmot met Sumi-Alpha® 200 EC en Sumi-Alpha® 200 EW • Plusia landmeters met DiPel® DF en Florbac® WG • Vroëroes met Sumisclex® SC Praat gerus met jou naaste Philagro-agent oor betroubare aartappelprodukte wat werk.

RAADPLEEG DIE ONDERSKEIE PRODUKETIKETTE VIR VOLLEDIGE GEBRUIKSAANWYSINGS & -BEPERKINGS. DiPel® DF (Reg. nr. L6441, Wet nr. 36 van 1947) bevat Bacillus thuringiensis var kurstaki. Florbac® WG (Reg. nr. L5531, Wet nr. 36 van 1947) bevat Bacillus thuringiensis var aizawai. Leimay® 200 SC (Reg. nr.

L10884, Wet nr. 36 van 1947) bevat Amisulbrom (sulfoamied), versigtig. ProGibb® 4% (Reg. nr. L5118, Wet nr. 36 van 1947) bevat gibberelliene, versigtig. ProGibb® 40WG (Reg. nr. L6777, Wet nr. 36 van 1947) bevat gibberelliene, versigtig. Rizolex® WP (Reg. nr. L6376, Wet nr. 36 van 1947) bevat tolklofosmetiel, versigtig. Sumi-Alpha® 200 EC (Reg. nr. L6452, Wet nr. 36 van 1947) bevat esfenvaleraat, giftig. SumiAlpha® 200 EW (Reg. nr. L8821, Wet nr. 36 van 1947) bevat esfenvaleraat, skadelik. Sumisclex® SC (Reg. nr. L6377, Wet nr. 36 van 1947) bevat prosimidoon. SumiPleo® (Reg. nr. L8377, Wet nr. 36 van 1947) bevat piradaliel dichloropropeen derivaat, versigtig. SumiPleo®, Rizolex®, Sumi-Alpha® en Sumisclex® is geregistreerde handelsmerke van Sumitomo Chemical Company, Japan. ProGibb®, DiPel® en Florbac® is geregistreerde handelsmerke van Valent BioSciences, VSA. Leimay® 200 SC is die geregistreerde handelsmerk van Nissan Chemical Industries LTD, Tokyo, Japan.

Philagro Suid-Afrika (Edms) Bpk l Reg. nr.: 98/10658107 PostNet Suite #378, Privaatsak X025, Lynnwoodrif 0040 Pretoria: 012 348 8808 l Somerset Wes: 021 851 4163 www.philagro.co.za

P R O D U K T E W AT W E R K V A N M E N S E W AT O M G E E

POTATOES

Awareness – potato spraing...

FROM PAGE 16

Photo 3: Internal necrosis on potato tuber caused by TRV. Source – Ephytia.

Photo 5: External necrosis on potato tuber caused by TRV. Source Ephytia.

Photo 4: TRV Internal necrosis. Source – AHDB.

remain viable in soil for many years. Transmission is made possible by zoospores which have flagella that aid them to move in soil moisture (therefore favouring wet conditions) that can infect the roots or tubers.

Transmission of the virus from an infected mother tuber to foliage is limited, and not all progeny tubers are infected. Affected tubers only transmit the viral disease to 20% to 50% of their progenies (Stent, 2011:48). PMTV will therefore self-eliminate due to low rate of transmission of the virus within the plant from seed potato to progeny (UNECE Guide to Seed Potato Diseases, Pests and Defects, 2020).

PMTV will be spread to the next planting in resting spores of Spongospora subterranea carrying the virus and present on potato tubers or contaminated soil. Movement of infected tubers or plants, soil, machinery or manure therefore increases the risk of spreading the disease.

18

Photo 6: Necrosis around lenticels caused by TRV. Source – Wisconsin Department of Agriculture.

Photo 7 More or less discontinuous necrotic arcs and lines caused

by TRV. Source – UNECE.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

AARTAPPELS

flesh of the tuber, almost continuously, unlike TRV-symptoms.

Tubers may also develop superficial raised rings without internal symptoms or develop no symptoms at all. Progeny tubers of infected PMTV material can be distorted cracked and russetted, with net like surface patches. (PMTV AHDB, 2020).

Photo 8: Bright yellow arcs or rings on the bottom leaves. Source – Ephytia.

Confusing symptoms PMTV or TRV can lead to the development of symptoms that may be confused with the following diseases or deviations: • Alfalfa Mosaic Virus (AMV) / Calico – Necrosis begins under the skin at the stolon end and extends to the entire tuber in the form of corky patches (Photo 11) similar to those induced by PMTV or TRV. • Internal Brown Spot – Small necrotic areas or brown spots of irregular shape and size occur in the internal area of the vascular ring (Photo 12) due to calcium deficiency which does not develop further in storage. Spraing caused PMTV and TRV can develop on the inside and outside of vascular ring.

• Potato Leaf Roll Virus (PLRV) – Brown necrotic spots around the vascular ring (tuber net necrosis) caused by PLRV (Photo 13).

• Potato Tuber Necrotic Ringspot Disease (PTNRD) – Thumb nail lesions (Photo 14) or brown blisters in the form

Photo 9: V Shapes on the upper leaves caused by PMTV. Source – Ephytia.

Symptoms on foliage The initial or primary infection does not give rise to foliar symptoms but on plants developing from infected tubers, depending on the potato variety and environmental conditions, PMTV may cause several types of symptoms. The most common symptom is the yellow spots or patches in the form of arcs or chevrons on the lower leaves (Photo 8).

Other symptoms include the shortening of the internodes of the upper leaves leading to a dwarfed bunched appearance (hence mop top) or yellow or pale green V shapes on upper leaflets (Photo 9), especially under cooler conditions. These symptoms are favoured by cool conditions.

Symptoms on tubers As with the symptoms on foliage, depending on the potato variety and environmental conditions, symptoms caused by PMTV on tubers may vary greatly (Stent, 2011:49). During the season of infection, the tubers of susceptible varieties may develop internal brown necrotic arcs or spraing seen as brown rings on the tuber surface. Sudden or prolonged temperature drop, for example cold storage, can induce concentric rings or lines (Photo 10), which often extend into the

Photo 10: Continuous internal necrotic lines. Source – AHDB.

Photo 11: Internal symptoms caused by Calico - Source (Potato - Tobacco rattle virus (TRV), 2020).

TO PAGE 20

GROENTE & VRUGTE | JANUARIE • FEBRUARIE 2021

19

POTATOES

Awareness – potato spraing...

FROM PAGE 19

of arcs, rings or lines (thumb nail) which remain superficial with only slight penetration into the flesh.

• Tomato Spotted Wilt Virus (TSWV) – TSWV can also induce external or internal concentric brown necrotic arcs, dark spots or internal necrosis and rot in the tuber flesh (Photo 15).

Diagnosis of spraing diseases is dependent upon symptom expression. Due to tuber symptoms being closely related, diagnostic testing is recommended. Soil testing could also be done for the identification of Trichodorus and Paratrichodorus spp.

In the United Kingdom, soil testing is done by allowing simultaneous detection of PMTV and TRV. Regulations limited the import of potato material to disease-free potato tissue culture material and mini tubers (G0 seed potatoes). The Potato Industry and the National Plant Protection Organization of South Africa (NPPOZA) work closely together to protect the potato industry from the introduction of new pests. However, potatoes are not the only pathway of introduction and therefore it is important to stay abreast with symptoms such as shown above to ensure early detected and eradication of such pests.

Should suspicious symptoms are detected, contact Potato Certification Service to assist with identification and the way forward.

20

Photo 13: Net necrosis caused by PLRV. Source – Ephytia.

References Ahdb.org.uk. 2020. Potato Mop Top Virus (PMTV) | AHDB. [online] Available at: <https://ahdb.org.uk/knowledge-library/ potato-mop-top-virus-pmtv> [Accessed 14 July 2020].

King, C., 2020. A Tuber-Damaging Strain of Alfalfa Mosaic Virus - Spud Smart. [online] Spud Smart. Available at: <https:// spudsmart.com/tuber-damaging-strain-alfalfa-mosaic-virus/> [Accessed 14 July 2020].

Mulder, A. & Turkensteen, L.J. 2005. Potato Diseases, Pests and Defects.

Stent, T. 2011. A Practical Guide to Diseases, Pests and Disorders of The Potato. France: FN3PT, GNIS & ARVALIS. Wale, A, Platt, H.W. & Cattlin, N. 2011. Diseases, Pests and Disorders of Potatoes.

Photo 14: Thumb nail type necrotic rings caused by PTNRD. Source – PCS.

Photo 12: Internal Brown Spot. Source – Ephytia.

Photo 15: Internal TSWV-symptoms. Source – PCS.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

BESPROEIING

Fertigation brings optimisation NETAFIM

The word fertigation might sound like something from a complicated medical journal. It is, however, an important concept from the world of irrigation. To farmers, this word means control. It means total control over the timing and quantity of each fertilizer delivery to a plant.

F

ERTIGATION IS THE delivery of fertilizer through irrigation. Flowing from its precision drip irrigation capabilities, the precision irrigation solutions company, Netafim, has coined the term, Precision fertigation™.

Precision fertigation is the optimal root-zone management tool delivering just the right combination of water and nutrients directly to the roots of each plant, according to crop development cycles.

Optimised control Fertigation allows the producer to completely optimise fertilization process and ensure that all fertilization is executed perfectly accurate. This, in turn, allows the producer to better control each plant to ensure optimal growth and minimal resource wastage.

The greatest advantage remains that fertilization can be ‘personalised’. Fertigation allows the producer to fertilize fields, or areas of the same field, where soil type and other factors differ, in a way that is perfectly adjusted to that field or zone. Furthermore, it allows the producer to only deliver the amount of fertilizer required by the plant at a specific life stage, never more and never less.

Fertigation limits fertilizer loss, as leaching is eliminated.

Dosages can be kept small but regular and can be perfectly timed to rainfall patterns and other factors. It further allows the producer to adjust applications according to any influencing factors that may pop up during the season. Be it market fluctuations, extremely low or high rainfall, poor crop growth, extreme weather events or disease occurrence.

Fertigation, if it is properly managed, can be implemented on most crops and in most areas.

The initial cost of implementing fertigation may be high, but the reward outweighs the cost over and over. Firstly, it results in saving fertilizer cost, labour costs, energy costs and

Fertigation limits fertilizer loss, as leaching is eliminated.

more. Secondly, the increase in yield, as a result of optimised fertilization, has been substantial time after time in Netafim’s experience.

Contact Netafim South Africa at infoza@netafim.com about solutions to make precision fertigation in a greenhouse or field possible.

The initial cost of implementing fertigation may be high, but the reward outweighs the cost over and over.

21

Take control of nutrient and water delivery with Netafim's Fertigation solutions.

0

FERTILIZATION

Balanced nutrition in potatoes Horticultural crops most suited to potassium nitrate applications are those that are sensitive to chloride, those producing high amounts of carbohydrates, those with regular topdressing frequency, crops grown in sandier conditions, lower pH conditions, fertigated and hydroponically grown crops and crops grown in cold climates.

P

REVIOUS ARTICLES IN Vegetables & Fruit have alluded to correct fertilizer applications in tomatoes; “The right choice for tomato production” (Sep / Oct, 2020) and in horticultural crops; “Excellent response documented with the use of potassium nitrate (Sep / Oct 2019). Potatoes are no exception.

Ultrasol® K Plus on potatoes* – Ultrasol K Plus **/ Qrop® K*** – KNO3 (potassium nitrate) The potato is a high value horticultural crop producing high volumes of dry matter. Potatoes are heavy feeders of both nitrogen (N) and potassium (K). The amount of potassium removed by tubers alone is shown in Figure 1.

Potassium removed by the whole plant is two thirds to double more than that removed by the tuber alone. This means that 8 – 8,8 kg of potassium is removed per ton of potato crop. The plant must obtain this K either from the soil or from applied potassium.

Similarly, potatoes require a total of 4,5 kg of N per ton potato crop. Potassium nitrate supplies both these macro elements.

Potatoes can benefit for the following reasons: • Optimum pH maintained around the roots (rhizosphere) Potatoes are grown preferably on the low buffer (cleaner marketable tubers) and lower pH soils (less diseases) and require large amounts of fertilizer.

At starting pH of around pH 5, if ammonium-nitrogen is applied, then the pH of the rhizosphere can decrease to pH 3.5. If nitrate-nitrogen is applied, the pH of the rhizosphere can increase to pH 6.5. The pH of the soil solution in direct contact with the roots can therefore be 1 000x more acid when ammonium- instead of nitrate-nitrogen is used.

• Competing cations (uptake antagonism) Plants like to maintain an electro-chemical balance. Ammonium-nitrogen is a positively charged cation. This directly competes with the uptake of other important positive cations such as potassium, calcium and magnesium.

Nitrate-nitrogen is a negatively charged anion which synergistically enhances the uptake of the positive cations of potassium, calcium and magnesium.

• Nitrification On sandy soils (<5% clay – predominantly in the Sandveld region of the Western Cape) the nitrification process is non-existent and applied ammonium fertilizer remains in the ammonium form.

Cold temperatures (winter plantings) as well as regular ammonium nitrogen applications will also influence the ammonium to nitrate ratio in the root zone. Any ammonium to nitrate ratio greater than 25:75 respectively is detrimental to plant growth and yield due to all the factors described in this article.

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Figure 1. The amount of potassium removed by tubers.

• Energy conservation Nitrate is converted into organic compounds largely in the leaves of plants. The energy for this process is driven by electrons excited by light energy in the chloroplasts of the leaves.

On the other hand, ammonium is converted to nitrogen compounds exclusively in roots. The energy used to drive this reaction is derived only from the burning of carbohydrates transported down from the leaves. An excess of ammoniumnitrogen causes a depletion of carbohydrates, which results in reduced dry matter accumulation reducing both yield and quality.

• Chloride and Potato Quality Although sometimes conflicting, chloride-free fertilizer has been shown to increase dry matter content, starch content and specific gravity of tubers. Chloride-free fertilizer is the preferred source for processing and chipping potatoes.

Growers using potassium sulphate exclusively as a potassium source to avoid chloride application, are applying excess sulphates creating nutrient imbalances in the soil solution. Sulfur, although important in plant nutrition, is required in much lower quantities and applied excesses can be loosely termed as “useless salts” creating unwanted salinity in the root zone.

• Balanced nutrition Using potassium nitrate, growers can maximise the application of nitrates and minimise the application of ammonium, a situation that cannot be obtained by using either potassium chloride (KCL) or potassium sulphate (K2SO4.). Therefore, with Ultrasol K Plus, the potato is being supplied with two of its main nutritional elements with the nitrogen in the correct form facilitating the uptake of the important cations. *All claims in this article can be substantiated with references which can be made available on request. **Reg No K5020 Act 36/1947. Registration holder Sociedad Quimica y Minera (Africa) (Pty)Ltd ***Reg No K5021 Act 36/1947. Registration holder Sociedad Quimica y Minera (Africa) (Pty)Ltd Disclaimer The information herein contained is given to the best of SQM’s knowledge and is believed to be accurate. The conditions of use and application of the suggested recommendations, are beyond SQM’s control. No warranty is made as to the accuracy of any data or statements contained herein. SQM specifically disclaims any responsibility or liability relating to the use of the recommendations and shall under no circumstances whatsoever, be liable for any special, incidental or consequential damages arising from such use.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

GENERAL

Landbou deur die oë van môre se leiers ‘n Groep van 17 jong landboukundiges het ‘n inspirerende blik op en visie vir landbou in Suid-Afrika aangebied tydens die afsluitingsfunksie van 2020 se ontwikkelingsprogram, Leadership in the Connection Economy. Hoewel die fokus akademies van aard was, het die krag van persoonlike ontwikkeling die kalklig gesteel.

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YNGENTA BIED JAARLIKS die Leadership in the Connection Economy program in samewerking met die Noordwes Universiteit se Sakeskool en Thinking Fusion Africa aan, met ondersteuning van Graan SA. Die program val onder die sambreel van die Leadership Academy for Agriculture.

Die ontwikkelingsprogram vir leierskap is spesifiek gemik op jong boere en rolspelers regoor die landbousektor.

Dit is in die lewe geroep om te help verseker dat landbou se toekoms nie aan toeval oorgelaat word nie, maar gevorm word deur jong boere toe te rus vir die uitdagings in hul bedryf.

“Met die Leadership Academy blaas ons lewe in leierskappotensiaal onder alle omstandighede,” sê Antonie Delport, sakehoof van Syngenta SA. “Sterk leierskap was selde meer nodig as nou. Verlede jaar se kontras tussen landbou se hoogs positiewe bydrae tydens die COVID-grendeltyd en die rasgedrewe botsings in Senekal, laat geen twyfel oor die kompleksiteite waarmee die bedryf worstel nie. Binne hierdie konteks staan die Leadership Academy met sy missie om toekomstige landbouleiers te vorm en te bemagtig.”

Die program was aanvanklik slegs op graanboere gemik, maar in 2019 is dit uitgebrei om alle soorte boerdery in te sluit en voorsiening te maak vir samewerking met ander rolspelers in die landbousektor. Saam met graan- en beesboere, was landbou-ekonome, voerkraalbestuurders, ‘n voorligtingsbeampte en ‘n grondgebruiksbeplanner

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Sommige studente van die ontwikkelingsprogram was Louis Steyl, René Uys, Mbali Nwoko, Mhlali Xhala, Harry van der Merwe, Gerswin Louw, Matthew Worrall en Carel Olckers.

deel van die 2020-groep.

Oor die afgelope sewe jaar het 225 landboukundiges die Academy se program voltooi.

Jong leiers in die kalklig Danksy die verslapping van die Covid-regulasies om geleenthede met beperkte bywoning toe te laat, kon die kandidate dít wat hulle geleer het persoonlik met ‘n paneel van belanghebbendes deel. ‘n Hoogtepunt van die geleentheid was ‘n toespraak deur Niko Mtimkhulu, ‘n melkboer en melkverwerker wat die leierskapontwikkelingsprogram in 2019 voltooi het.

Die ondervinding het ‘n blywende indruk op hom gemaak. “Ek het onder meer besef dat die lewe vir niemand perfek is nie, nie eers vir wit boere nie,” sê Niko. “Ek het besef dat ons almal in dieselfde bootjie is en dat ons dieselfde wense het, soos om suksesvol te wees en ‘n erfenis vir ons gesinne na te laat.”

Hy noem dat boerery ‘n eensame besigheid kan wees, veral vir jong mense, en dat die netwerke wat boere en ander rolspelers in die bedryf tydens die program bou, ‘n belangrike bron is van die ondersteuning wat in die bedryf nodig is.

As ‘n talentvolle en welsprekende debatvoerder, voeg Niko by dat die

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

ALGEMEEN

‘n Paar tema’s het soos goue drade deur die studente se aanbiedings geloop: geen genade vir korrupsie, die noodsaaklikheid vir sterk bestuur en ‘n bevoegde staatsdiens, vertroue wat tussen alle belanghebbendes in die landbousektor gebou moet word, verbeterde kommunikasie, en leiers wat dapper is en hoop verkondig.

Die afgeronde aanbiedings was egter net ‘n voorsmakie van die groot persoonlike ontwikkeling wat die kandidate ondergaan het sedert die program in Februarie 2020 afgeskop het. In getuigskrifte wat ná die formele aanbiedings gelewer is, het die jong manne en vroue gepraat van groei in selfwaarde, selfvertroue en bevoegdheid in Engels, saam met beter begrip en meer empatie oor ras- en geslagskeidslyne heen.

Die verhoudings wat tussen nasionale leiers gebou word, moet op plaasvlak weerspieël word.

leierskapontwikkelingsprogram hom ook geleer het om regtig te luister en te verstaan voordat hy reageer.

Hierdie perspektief van ‘n alumnus onderstreep die belangrikheid van die Academy se klem op self-ontdekking en bemagtiging, die ontwikkeling van leierskapvaardighede en om môre se landbouleiers betrokke te kry by die sektor se huidige uitdagings.

Die manier waarop die studente drie sulke uitdagings bestudeer het, was die hoof-item op die afsluitingsgeleentheid se sakelys. Ingedeel in drie groepe, het hulle hul begrip van elke uitdaging uiteengesit, gevolg deur moontlike resultate en die strategieë wat nodig is vir die verlangde toekoms.

Die landbou-uitdagings wat uitgelig is, was: ‘n verdeelde sektor met ‘n swak openbare beeld; openbare-private vennootskappe kan help om groei te ontsluit, transformasie te verbeter en voedselsekuriteit te verseker; die vyandige ekonomiese omgewing wat kommersiële boere in die gesig staar.

Landbou kan die leiding neem ‘n Atmosfeer van persoonlike outonomie het geheers, saam met die oortuiging dat landbou baie meer kán en behoort te doen as om vir mense kos te gee. Soos Jannie de Villiers, hoofbestuurder van Graan SA gesê het: “Landbou kan hierdie land heel maak”.

Hy het die klas van 2020 aangemoedig om dít wat hulle in die Leadership Academy vermag het, op hul plase en in hul landboubesighede en gemeenskappe

te gaan herhaal.

“Die verhoudings wat tussen nasionale leiers gebou word, moet op plaasvlak weerspieël word. Die sagte vaardighede wat by die Leadership Academy geleer word, is broodnodig om verhoudinge te verbeter. Ons land kan nie die khaki-vs-rooi-stryd bekostig nie.”

In sy toespraak het Antonie Delport, sakehoof van Syngenta SA, die hernieude waardering vir boere as voedselprodusente wat uit die Covid-19 ondervinding gespruit het, uitgelig.

“Ons het deur die grendeltyd gekom sonder dat produksie gestop het. Nou moet ons aanhou wys hoe ons kan saamwerk en hoe suksesvol ons kan wees. Meer as ooit het ons ‘n volledige stel vaardighede nodig om slimmer te kan boer, en dit is waarom die Leadership Academy bestaan.”

As ‘n alumnus en agri-entrepreneur, het Niko die klas van 2020 uitgedaag om dapperheid bo gemak te kies. “Ons het die geleentheid om die toon aan te gee vir ons nasie. Almal hou ons as boere dop. Laat ons dus die land in die rigting stuur waarin ons wil hê hy moet gaan deur ons waarheid te praat en geïnspireerde aksie te neem.”

Besoek www.leadagri.co.za vir meer inligting en om aansoek te doen.

Onder die studente wat 2020 se program voltooi het was Lindiwe Nkoala, René Uys, Nobuhle Gumede, Harry van der Merwe, Jan Teubes, Johan Potgieter en Johan Nel.

GROENTE & VRUGTE | JANUARIE • FEBRUARIE 2021

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GENERAL

PMA Fresh Summit – a technological marvel JAN GREYLING Co-worker The learning curve initiated by a need for new technology continues to spike upward in the value of dynamic and innovative communication, networking and exhibition platforms engaged by the Fresh Produce Association (PMA) and its affiliates. As a figure of speech, the very first virtual Fresh Summit organised by PMA, in its existence of more than 70 years, was a remarkable feat on top of what has been achieved by the PMA through continual PMA Talks and regional conferences, since initial lockdown regulations first kicked in internationally.

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T SEEMED TO be virtually impossible to visualise the physical possibility of a global Fresh Summit bringing together 64 nations represented by 360 exhibitors and attendees during this milestone event. To contribute even more to the wide array of events, 2020 PMA Fresh Summit offered 21 hours of educational material shared by 31 hand-selected speakers.

Due to the actual need for a proper international gathering for the industry, the opening State of the Industry presentation was presented by PMA’s CEO, Cathy Burns, and was attended by almost 2 000 live viewers.

Not only did key industry role players and decision makers tune in and networked from across the globe to attend and share in essential and intriguing information sessions over the course of three days. They actively visited the virtual exhibitions and information desks throughout the event, without having to leave their homes.

Participating exhibitors embraced the opportunity and they experienced the virtual platform to be constructive. According to PMA’s Crystal Chavez, from Gold Coast Packaging, it was very user-friendly. “Being able to virtually meet the companies we deal with and all attendees while having insights in their interests, was really useful.”

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She added that physical exhibition attendees often do not wear name badges, or they purposely flip it around. At virtual Fresh Summit 2020 everything was visible. It was great to see the identity of everyone.

According to Michael DuPuis with Divine Flavor, Fresh Summit time is set aside each year to interact and let customers and buyers know that their business is a dependable supplier. “We need to be there for our customers. Participating in this annual showcase is part of that,” he said.

DuPuis mentioned that it is not easy doing the exhibition virtually while trying to achieve the same goals one can achieve personally. “Nonetheless, overall we enjoyed a great turnout.

To us, Fresh Summit 2020 has been a functional platform to take advantage of.”

Another word of approval came from Andy Garcia III with Altar Produce. “Given the circumstances, I’m very positive about the opportunity to connect, interact, and engage with others in the industry versus having no show at all.”

Oppy’s Gardner showed gratitude for being able to participate as a presenting sponsor. Oppy observed the advantages of effective analytics on the virtual platform. “Receiving the daily list of visitors to our booth from the organisers really enabled

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

ALGEMEEN

us to act swiftly. We could give direction to attendees and put them in touch with the right people.”

Shannon Boase endorsed this remark. “Look, no one wants to waste anyone’s time, so knowing who could be interested in your product, is helpful in targeting a message that’s succinct and on-point,” she noted.

Since virtual business is a given within the new normal and many stakeholders are in the process of adapting, not all exhibitors experienced the virtual ‘show ground’ to be an effective way to interact. Garcia found the scheduling of meetings with (potential) customers to be complicated. “I reached out to several people trying to pre-arrange meetings, but only a few responded. From exhibitor feedback it became clear that the platform has been of good use to reinforce existing relationships. It seems however, that it was extremely difficult to initiate new business. As one respondent mentioned, ‘It’s not the fault of PMA, but it’s just the nature of a fully virtual setup for an industry that relies so heavily on relationships.’ ” Garcia added that according to him, the one outstanding contrast for each exhibitor between in-person and virtual exhibitions were that daily duties of each participating exhibitor continued during the three-day event since they did not leave the physical office or market environment.

Representing CFK, Inc, Shannon Boase was excited about the interaction they generated during virtual Fresh Summit 2020.

“There was definitely a lot of upfront work that was required, from new content creation to sales training. However, we were able to get meetings with retailers that we are not normally about to get at the face-to-face show. That was a big benefit,” Boase said.

Oppy’s Gardner shared that: “We had a nice blend of customers, media, friends, and friendly competitors popping by virtually, but we dearly missed seeing the international produce community in person.”

As is the case during in-person events, Sandra Somford with JASA Packaging Solutions pointed out that they had good first meetings with potential customers but expects “most of the conversations will take place after the event.”

During Fresh Summit, the annual Fresh Ideas showcase presented 150 products. Exhibitors were positive about the attention paid to their new products. “Our new fresh organic ginger packs caught the eye of visitors,” Oppy’s Gardner said.

According to Sandra Somford of JASA Packing Solutions, their Exhibitors Highlights and the introduction of the new Sleever for tomatoes definitely caught the attention of most attendees. She remarked that their participation in the Fresh Ideas showcase yielded them the most new contacts.

Gold Coast Packing impacted on visitors with their all-new broccoli slaw and a garden blend in 0,91 kg (2 lb.) format, according to Chavez from the group.

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Are you doing business with a REGISTERED AGENT? FRESH PRODUCE

LIVESTOCK

EXPORTS

It is a criminal offence for a person to act as an agent without registering with the Agricultural Produce Agents Council (APAC).

Do not support illegal traders and only use the service of a registered agent as reflected on our website.

Tel: (011) 894-3680, 087 095 1335, Fax: 086 669 9178

www.apacweb.org.za

GENERAL

A salad for every palate JAN GREYLING Co-worker An amazing world of innovation and convenience is getting unwrapped within the world of salad combinations and presentations. Amidst fierce competition and daily adaption to fast changing consumer preferences, the virtual 2020 Fresh Summit learned much about the creative and imaginative salad revolution.

O

N AN ON-GOING rotation of the wheel of improvement new consumer friendly varieties of traditional salad favourites are cultivated and fine-tuned to be tastier, healthier, more shelf life friendly, easier to use, more nutritional and – wait for it, more eye-catching and lifestyle friendly.

Be it aimed at individual office dweller lunches, home alone singles, small or larger families or the catering industry the competition is open, it is intense, and to the benefit of the end consumer, growers, processors and the packing materials industry.

A cornerstone of the industry With their recent salad launches, Taylor Farms in California is taking the salad consumables sector up a notch, to tease the palates of consumers. According to Quincie Gourley, Marketing Coordinator, the packaged salads category is regarded as a cornerstone of the fresh produce industry. She said the salad department is “a source of inspiring flavour, recipes, and innovation throughout any retailer’s fresh space.”

Gourley said their motivation is the increasing consumer need for convenience and more unique and trending salad flavours. By researching consumer needs and launching demand driven products Taylor Farms is truly laying the groundwork for addressing what the consumer wants and desires in their daily diets and convenience preferences.

These innovative salads are making their way to retail shelves as shoppers look for more convenient and flavourful ways to shop. “We continue to innovate and provide pro-

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ducts and services that fit our customers and consumer needs.”

Clean plant-based preferences In New York, Ark Foods introduced a new line of packaged salads at the PMA virtual show, during the summit. The Clean Label Salad line-up “is sure to bring in the consumer crowd who are adjusting to the new normal swiftly, some tasty and healthy new clean and plant-based salad offerings,” said CEO, Noah Robbins.

Robbins said these new salads are prepared from “ingredients your great-grandma would recognise. These prepared salad meals serve as easier, healthier, affordable lunch options, amidst a 40 percent rise in home cooking seen from the COVID-19 pandemic, as stated by The Food Industry Association.”

The interesting new kids on the Ark Food salad block feature updated nods to classic salads, with vegetables “rarely seen in ready-to-eat salads, including watermelon radish and golden beets”. These salad innovations range from 330 -410 calories and deliver between 13 - 18 grams of protein for consumers focused on getting energised while achieving health goals.

South African produce growers and ready-to-eat salad suppliers should also note the inclusion of pepitas, cashews, red carrots, red cabbage, sundried tomatoes and brussels sprouts, combined with dressings including vegan pesto, plant based ceasar, ginger sesame and chickpea croutons. These new options are wellness based and will be on shelves in the United States in January 2021.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

ALGEMEEN

Healthy living will pay off JAN GREYLING Co-worker It might be a crazy time to take the chairmanship of the Produce Marketing Association, but incoming chairman Dwight Ferguson, President and CEO of the California Agricultural Leadership Foundation, has some ambitious but realistic goals.

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HARING HIS INAUGURAL thoughts, Ferguson said during the historic virtual Fresh Summit that he is excited about the contribution he might be able to make in helping to execute PMA’s new strategic plan. “I really look forward to increase our PMA membership base globally.”

Measured against the revolutionary innovative thought, strategy and plan implementation by PMA since the start of Covid-19 lockdown restrictions in March 2020, he noted that PMA has “delivered the industry more content than ever before, and we should look for that to continue”.

Ferguson invited members and the industry to see even faster progress in the field of technology as he anticipated the launch of an extensive new consumer research platform in the early parts of 2021. “This development will address market intelligence gaps in produce and floral,” he said.

He committed PMA to continue promoting fresh fruits and vegetables as part of a healthy diet “but also essential to a healthy life. “Our vision remains to bring together the global

produce and floral communities to grow a healthier world”.

He said that PMA will use some new “filters” to unite floral and produce stakeholders internationally. These include: • A sharper focus on improved global relations with produce and floral sectors.

• A renewed and continuing effort to deliver non-stop differentiated value in “ produce safety, technology, sustainability, talent, and demand creation.”

• A view of inclusion of a more diversified membership “to ensure we do all that we can to welcome new talent and new thinking into our community”.

• An exponential expansion of the PMA reach to include all who are passionate about “the joy of fresh produce and floral”.

The newly elected PMA Chair concluded in saying: “Now more than ever we must reinforce the importance of produce and floral as part of a healthy lifestyle – in body and spirit.”

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Contact us on: +27 (0)11 692 1658 www.knittex.co.za clientliaison@knittex.co.za

PROTECTS YOUR CROP AGAINST SEVERE WEATHER CONDITIONS (I.E. WIND, SUNBURN, HAIL DAMAGE, BIRDS AND LARGER INSECTS)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ INSECT COLUMN

Potato tuber moth (Lepidoptera: Gelechiidae)

Potato tuber moth is indigenous in South America and is now distributed all over the world. Potato is the main host plant of the potato tuber moth. However, it also attacks other Solanaceae plants such as tomato, tobacco, chilli, aubergine and cape gooseberry. It has also been reported to attack several related wild host plant species. Other common names of the potato tuber moth include potato moth, tobacco leaf miner and tobacco splitworm.

Nozibusiso Maphumulo IPM-PROGRAM, NORTH-WEST UNIVERSITY POTCHEFSTROOM

e-mail:mashimanenozi03@gmail.com

Potato tuber moth classification:

Class: Insecta (Insects) Order: Lepidoptera (moths and butterfIies) Family: Gelechiidae Genus: Phthorimaea Species: Operculella

E

GGS OF THE POTATO tuber moth are oval in shape and yellowish, iridescent in colour. Larvae are about 15 mm long when fully grown. The body is greyish-white or pale greenish-grey with a dark brown head. The pupa has a yellowish or reddish brown colour. Adults are small and elongated with a length of 8-10 mm. They are pale brown in colour with darker marbling and brown antennae.

Potato tuber moth lays its eggs either singly or in batches on the leaves or exposed tubers of the host plant. It lays between 40 to 290 eggs. Egg laying is completed within 3 days.

Eggs hatch within 3 to 15 days in summer, and it may take up to 58 days before hatching occurs in winter. After hatching, the larvae bores into the petiole or young shoot or the main leaf vein, where it mines the leaf, resulting in the formation of a blotch. It then bores into a tuber at a later stage and forms a long irregular gallery (passage). The larval stage takes approximately between 13 and 33 days to complete. Pupation occurs in the soil and the pupal stage ranges between 6- 29 days. Moths can survive for a period of up to 10 days.

They are nocturnal and are attracted to light. Its life cycle can be completed within 17 - 125 days. Potato tuber moth can

Figure 1: Potato tuber moth. https://cropserve.co.zw/potato-tuber-moth/

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Figure 2: Potato tuber moth larva inside the potato tuber and its inflicted damage. https://news.cornell.edu/stories/2016/05/potato-plants-get-defensive-after-underground-attacks

Figure 3: Signs of potato tuber worm damage on the potato tuber. http://entnemdept.ufl.edu/creatures/veg/potato/potato_tuberworm.htm

have up to 13 generations per year where climatic conditions are favourable.

Potato tuber moth is a major pest of potatoes, more especially in areas where climatic conditions are favorable. It is also an important post-harvest pest of potatoes. Feeding damage can be observed as mines in the leaves, leaf stalks and stems.

Tunnels inside the tubers are a clear indication of infestations by the potato tuber moth. The larvae of the potato tuber moth mines potato leaves during the growing season and tunnels through the tubers while feeding on them and filling them with their frass. Damage inside tubers is only noticeable during harvest time.

Prevention and control measures can be achieved by using specific chemicals. Cultural control can also be used to control this pest by using healthy tubers during planting to minimise infestation levels, because re-infestation occurs as a result of using infested seed tubers. Integrated pest management (IPM) is the best solution towards tackling this pest.

JANUARY • FEBRUARY 2021 | VEGETABLES & FRUIT

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