TECHNICAL
HIGHLIGHTING BIOSECURITY RISKS FOR FRESH VEGETABLE GROWERS Words by Lisa Wong : Research & Technical Specialist, Market Access Solutionz Ltd
Cucumber green mottle mosaic virus is a Vegetables New Zealand priority pest CGMMV is a pathogen that affects cucurbit host crops such as watermelon, honeydew melon, rock melon, cucumber, zucchini, scallopini and pumpkin, and is one of Vegetable New Zealand’s priority pests. It is also important for the New Zealand Buttercup Squash Council. CGMMV was first described in England in 1935. Since its discovery it has spread across Europe, Asia, and North America. Its spread accelerated from the mid-1980s, and by 2016 it had spread to North America and arrived in Australia. If CGMMV arrived in New Zealand, it would have a major impact on the local production of cucurbit crops. There is no known cure for CGMMV.
Figure 1: Fall armyworm larvae and damage to a corn ear, Image source: University of Georgia, Bugwood.org. Creative Commons 3.0
Monitoring the activity of emerging pests and diseases around the globe helps growers prepare for and manage biosecurity risks that could threaten vegetable production in New Zealand. New pests and diseases are continually emerging and causing damaging effects on many crops and could be a risk to New Zealand. Vegetables New Zealand regularly monitors several pests and diseases because they have a greater potential to enter, spread, and become established in New Zealand on vegetable crops – these are termed ‘priority pests’. Many of Vegetables New Zealand’s priority pests are common to other vegetable product groups, such as fall armyworm (Spodoptera frugiperda), vegetable leafminers (Liriomyza spp.), and chilli thrips (Scirtothrips dorsalis), while other exotic pests and diseases are important to only one or two vegetable product groups (see VR&I article in this issue), for example, Cucumber green mottle mosaic virus (CGMMV).
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NZGROWER : MAY 2021
CGMMV is a pathogen that affects cucurbit host crops such as watermelon, honeydew melon, rock melon, cucumber, zucchini, scallopini and pumpkin, and is one of Vegetable New Zealand’s priority pests Symptoms of CGMMV infection are light green mottling and mosaic patterns on the leaves, blistering and distortion (Figure 2). It can also cause plants to be stunted, and importantly, it can cause severe crop losses. New Zealand imports a large quantity of cucurbits from Australia, especially watermelons, melons, and zucchinis. In December 2019, CGMMV was intercepted on a consignment of fresh watermelons being imported from Queensland. The consignment was suspended, and Australian authorities asked to investigate the situation. After Australian authorities put in place measures to satisfy the Ministry for Primary Industries that future exports of cucurbits would be free of the virus, importing cucurbits from Queensland was reinstated in March 2021. Fresh cucurbit imports from Australia are now required to be sourced from an accredited property that is a ‘pest-free place of production’. The Import Health Standard for Fresh Produce has also been amended to reflect the requirement for a ‘pest-free place of production’.
