Potato Review

38 POTATO REVIEW JULY/AUGUST 2020 STORAGE “In some situations, sprout control with ethylene has actually been better than with CIPC because, as a dynamic gas, it distributes easily in stores and is less reliant on even ventilation.” Je added that it is important to manage CO 2 levels in store with daily ushing with fresh air as CO 2 , particularly in combination with ethylene, can a ect fry colour. Concern about ethylene use in leaky stores is also misplaced, with a well-sealed environment less critical than if using a volatile alternative such as spearmint oil applied as a hot fog. “ is is because the generator will try to [constantly] maintain ethylene at the required level. You also get the added bene t that leakier stores will have less CO 2 build up,” he said. Fry colour McCain has seen a slight shift in fry colour when compared to equivalent CIPC stores, but any shift tends to be slow or gradual, slight and experience has shown it to be manageable. To date the company has not had any issue with potatoes delivered to factory that speci cally relate to ethylene use. Je says with limited options post-CIPC, it is positive for the industry that McCain’s work has demonstrated the good e cacy of ethylene for its French fry variety storage. is e cacy is particularly apparent when used in conjunction with a well-timed foliar application of maleic hydrazide (MH) ahead of haulm destruction. However, he appreciates that ethylene may not be the solution for all situation or markets and McCain do allow the use of spearmint oil on its crops. e company would also welcome the UK registration of 1,4-dimethylnaphthalene (DMN), expected this autumn. “It is already approved and being used in a number of European countries. We would like to gain commercial experience with it here in the UK and see it possibly as a rst application to enhance dormancy then in combination with ethylene,” said Je . McCain has opted to use an ethylene delivery system from Peterborough-based Restrain “In some situations, sprout control with ethylene has actually been better than with CIPC because, as a dynamic gas, it distributes easily in stores and is less reliant on even ventilation.”