Potato Review

18 POTATO REVIEW JULY/AUGUST 2021 SPROUT SUPPRESSION T HERE is a consensus that potato sprout control now starts in the eld following very positive results from a timely application of maleic hydrazide before haulm destruction last summer. Many column inches have been dedicated to the subject in recent years, initially covering the uncertainty around long- standing in-store treatment CIPC and how the industry might prevent its withdrawal. Once that was announced, there followed a knowledge exchange drive to help growers manage sprouting in store without the safety blanket of three or four CIPC applications. What has now emerged is the importance of maleic hydrazide as the rst step in sprout control programmes, which must begin before the crop is even lifted from the ground. at’s according to agronomy group Frontier’s crop protection commercial manager Nick Badger, who says there was a huge uptick in its use in potato crops in 2020, mostly on the processing side, but also in crops destined for packing. Nervousness While CIPC’s withdrawal was the obvious driver, he says there was also nervousness Sprout suppression starts in the field with maleic hydrazide As we approach the nal stages of the 2020-21 storage period, Potato Review nds out how growers have managed sprouting in the rst year without CIPC. about relying solely on products growers and store managers had no experience with. “For many, it was the rst year using mint oil or an ethylene system. ere has also been uncertainty about the availability of DMN (1,4-dimethylnapthalene), with the product still not fully approved for use in the UK,” he said. “ is meant that not only was there more focus on the use of maleic hydrazide to help manage sprouting early in the storage period, but also the acceptance that application must be spot on to maximise e cacy.” Nick says reports on the e cacy of maleic hydrazide have been very positive and attributes this to increased attention to detail ahead of application. Because growers have just one shot to get it right, he says many carefully identi ed the “sweet spot” – a window about three to ve weeks prior to haulm destruction. “Planning was much better, along with monitoring of weather and managing other jobs that can impact on uptake of MH by the crop, such as irrigation. “In the past, it has often been an afterthought, because everyone had the insurance that CIPC could get you out of trouble.” “We put a lot more e ort into planning application than we had before.” John Benton, grower Nick Badger says sprayer e ciency has been key to helping growers apply MH during the sweet spot. Adam Palmer’s business grows 200-220ha of processing potatoes each year on organic soils around Ely. Norfolk grower John Benton focused more attention to application of maleic hydrazide this year. A new label requirement this year sees the IBCs combined with a FasTran 850 closed transfer system.