Potato Review

www.potatoreview.com POTATO REVIEW SEPTEMBER/OCTOBER 2020 13 DISEASES canopy with rotating nozzle increases chemical deposition on the seed tubers.” Operator training and seasonal equipment testing is a vital part of any system, he stressed. All equipment should be purchased with a back-up parts and service contract as in-season breakdowns can be costly. PA 12 training and NSTS certi cation should be part of any machinery purchase. Both David and Paul feel there will be a di erent approach required for individual varieties and this may change with harvesting conditions. High risk varieties and high risk end markets need special attention. Treatment options Treatment programmes to consider: When harvesting high risk varieties in dry conditions an application of Gavel is bene cial. Stocks should be graded and boxed on the grading line before going onto a drying wall. ere is the option to treat with a combination of Storite Excel and Gavel to the seed fraction only. Using a roller table and canopy gives good coverage. Variable speed motors will keep the roller table full at di erent throughputs. Harvest straight on to the drying wall and cure the skins with good quality air. Stocks that have been loaded straight onto a drying wall & cured can be split graded & the seed fraction treated at the earliest is may be an option if lifting in di cult conditions. ere is an option to treat just prior to dispatch in the spring “ is is currently popular but we feel is not a good option as the current chemicals have little activity on established disease and it is shutting the door after the horse has bolted,” said Paul. It costs approximately £10 for a Gavel and Storite Excel mix and is not cost e ective to treat later, David added. “If the ware grower has concerns, there is an option to use Maxim 100 FS that has some activity in reduction of dry rot and skin spot. It also brings in black scurf control. It is a broad spectrum fungicide and good value for money,” he said. Both David and Paul believe the seed industry needs to make the logistics of seed delivery to the ware grower more integrated. ey say less grading and better co-ordinated delivery to the ware growers would help avoid issues of rejection and high seed losses at nal grading. While most growers would like clearer chemical labels and an answer to the stock feed issue which blights many current active ingredients, this is not likely to happen any time soon so we must all take a new look at what actions we can take ourselves, the agronomists stress. ey advise discussing the seed treatment you require with your supplier and ensuring it will play an active role on the pre delivery treatments and storage. While seed labels give information about what has been applied, you should still check WHEN this was applied – an oversight which happens all too frequently. Emergence issues in a ware crop from dry rot. Late expression of dry rot