Grapevines can be particularly susceptible to herbicide trespass from other crops, and some active ingredients can travel for many kilometers before settling on grapevines.
While subsequent leaf damage can be evident throughout the growing season, pre-vintage is an ideal time to look out for this damage while you are undertaking activities such as collecting bunches for maturity testing or pest and disease monitoring.
To help growers identify visual symptoms of herbicide drift on grapevine shoots, leaves and fruit, from soon after herbicide contact, to over time, refer to DPI NSW’s fact sheet.
While damage is often patchy, growers are encouraged to assess the extent of symptoms, before reporting to either the Agricultural and Veterinary Chemicals Hotline on 1300 799 684, or emailing pirsa.ruralchemicals@sa.gov.au. We strongly suggest reporting damage to your contracted winery as well. Whole vine panels or rows displaying symptoms should be of concern.
Late 2023, PIRSA – Rural Chemicals Operations released their Chemical Trespass Annual Report 2022-23 on Complaints and Investigations. Notable findings in this report for the wine industry include:
- 32 incidents were reported in 2022/23, but in effect they cover only two trespass incidents, one affecting a winegrape growing region (Clare).
- “Boom-sprayer applications produced the greatest number of complaints, followed by air-blast sprayers (orchard and vineyard sprayers).” Grapegrowers should be particularly wary to avoid spraying across the boundary. Given the higher release height from air-blast sprayers, spray droplets can spread further than from boom sprayers, and are more prone to drift as wind speeds typically increase with increasing elevation.
- “Half of the chemical trespass complaints in 2022/23 involved a separation distance of less than 50m between the complainant and the chemical use.”
- “Off-target herbicide damage to viticulture, particularly summer damage that is generally thought to be caused by spraying of summer weeds in unsuitable weather conditions by dryland cropping farmers, has been a recurring problem in SA. Significant resources have been devoted to educating growers about spraying in suitable weather conditions.”