Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2021 59 EVENTS D EVELOPING a robust resistance management strategy in potatoes depends on a willingness to plan, the use of alternative modes of action, and the adoption of future technologies, attendees at an industry-focused webinar heard recently. The session was hosted by Agri-Tech Innovation Centre, Crop Health and Protection (CHAP), and featured keynote speaker Dr Faye Ritchie from ADAS. Dr Ritchie opened discussions by exploring the subject of managing pesticide resistance in potato crops, including the best use of available chemistry in targeting late blight. Owing to the evolution of resistant strains of the disease and withdrawal as a result of legislative changes, Faye said this could eventually leave only eight viable modes Helping farmers develop a robust resistance management strategy of action available to growers. Therefore alternating between these within the spray programme, or using approved tank mixes and co-formulated products, was the most effective approach to help manage resistance development. Other tactics such as adjusting spray timings were not as effective for resistance management. Faye said: “Potato growers are faced with two main challenges when it comes to overcoming late blight – fungicide availability and changes in the pathogen population. The two are linked. Developing a robust strategy for resistance management based on an integrated approach will also help to overcome the issue of fungicide availability - particularly pertinent given the status of mancozeb. “The first steps should always be to take time to devise a plan ahead of the season, that includes non-chemical strategies such as controlling potential sources of the pathogen, for example outgrade piles. “Using fungicide tank mixes, co-formulated products and alternating modes of action in the fungicide programme are known to be effective use of available chemistry. Of course, as we move into the future, we will have to become more reliant on other measures such as resistant cultivars and decision support tools.” Dr Ritchie concluded by discussing the role of resistant cultivars in allowing greater spray programme flexibility and the potential to reduce dose rates. Business Development Manager for CHAP, Chris Delf, discussed the growing role of decision support systems in potato production. This included an introduction to CropMonitor Pro – an independent ➜