Onions NZ Inc

GROWER TOOLS FOR DOWNY

MILDEW AND DISEASE MODELLING: A PROACTIVE APPROACH TO THE COST OF INPUT CRISIS

Kazi Talaska : Onions NZ

With agriculture input costs at an all-time high, the pressure to achieve more for less is increasing for growers in our sector. There is a power struggle between yield, quality and cost of input that will only increase when disease pressure is high.

A wet and warm season is predicted with the oncoming La Niña southern oscillation weather pattern. These conditions are favoured by fungal diseases and will increase the likelihood of spore germination and spread between plants. Onions New Zealand has been working with New Zealand agri-tech company HortPlus to develop a disease modelling tool – the Onion Downy Mildew Tool – that supports growers to identify when conditions are high for infection and germination. Considered an industry-leading digital tool based on HortPlus’ MetWatch Platform, the model uses a nationwide network of scientific-grade weather stations and pest and disease models to provide local weather insight, powerful forecasts and agricultural weather data. HortPlus maintains weather stations located in key growing regions, with an emphasis on coverage in Pukekohe, Canterbury and Hawke’s Bay. Key features of the tool include risk models for diseases, including onion downy mildew and Stemphylium, as well as weather and forecast information and daily email reports that are sent to growers in a PDF format that are easy to read and shareable. This information is available online and accessible from any device. Disease models display an infection summary that summarises favourable sporulation and germination – by hour and by day. These tables are supported by wind, drift risk, wetness and rainfall data. For growers, this could mean the difference between spraying or choosing not to spray during a disease susceptible period. “The Onion Downy Mildew Tool is particularly important to growers because if this disease gets away on you it can be really devastating, and is a gateway for secondary diseases such as Stemphylium,” says HortPlus director Mike Barley. “The disease models are particularly useful for timing key sprays in the early season, and the daily email reports give a great indication of the disease risk pressure, that you can assess over your morning coffee.” The Onions New Zealand Weather and Disease Portal is free to access for Onions NZ members. Growers and agronomists across the country can use it daily to make business critical decisions about pest and disease risk periods, spraying and irrigation schedules, the best times to plant and harvest crops and more.

To access the Onions New Zealand Weather and Disease Portal, visit: www.onionsnz.com Login, then click “Weather and Disease Platform”

Tools such as the Weather and Disease Portal are a step towards better integrated pest management (IPM), which when practiced well, will decrease the reliance on agrichemicals, improve environmental outcomes, and decrease the cost of production. Visit the Onions New Zealand resource library to access best practice IPM resources and guides.

The MetWatch portal can send daily email reports to users