Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2020 35 MH: FOLIAR APPLICATION Volunteer control ere are other bene ts from MH including volunteer control. Certis trials in the Netherlands suggest an average of 70-90% of treated tubers left behind after harvest are unviable. With volunteers propagating soil borne diseases, late blight, virus and potato cyst nematode (PCN), this will assist IPM around the rotation. MH also reduces secondary growth, is the only treatment to control internal sprouting – where a sprout turns inwards beneath the eye and grows through the inside of the tuber – and limits chain tuberisation. e latter can reduce dry matter content in tuber samples and MH negates this. Adrian says there is a concern that users may not be fully reaping the sprout control bene ts of MH, as he sees some variability in e cacy and sees application timing as the biggest factor. ere is a risk of a yield penalty when the product is applied too early, but Adrian feels this has been overstated, resulting in some growers applying too late and compromising uptake into tubers. Di cult job “However, it has to be acknowledged that unlike treating potatoes in store, where conditions are fairly constant, out in the eld there are many variables which makes it much more di cult to get right.” Simon Alexander, an independent potato specialist advising across East Anglia, believes many growers won’t miss the opportunity to use MH this season and get some peace of mind that dormancy break will be delayed once crops go into store. Like Adrian, his experience of MH has been variable with some crops showing little response and others still dormant the following April. “I think that’s largely down to application timing and conditions and my concern is that there hasn’t been a signi cant amount of UK research into MH use in recent years. “But with an increased focus on the importance of MH now CIPC has gone, I think our application will improve and that variability should reduce. We should get what we need out of the product,” he adds. Application is king While there haven’t been extensive MH trials carried out in the UK, Crown MH marketing company Certis Europe’s technical specialist Fokke Smit has been working with the active in the Netherlands since 2010. ➜ Maleic hydrazide is a good sprout suppressant in its own right, helping to prevent sprouting for months after application. Photo: Gary Naylor WWW.AGRIMECH.CO.UK +44 (0) 1354 638 222 Supporting you where ever, when ever Remote, faster access to engineer support when you need it