Potato Review

www.potatoreview.com POTATO REVIEW JANUARY/FEBRUARY 2023 15 In the 2020/21 season, we only had BIOX-M for sprout control for crisping potatoes and, after a nervous start, we soon realised it would work successfully. Now that we have an alternative option, we feel con dent that we can manage sprout control through to July. “A word of warning - make sure the ARGOS fog isn’t hitting the crop in large quantities because it will scorch or burn the potatoes. We fogged many stores last season and experienced crop damage issues in just two. We feel con dent with our current knowledge it will not happen again.” ‘Good e cacy in store’ Tim Kitson, an independent potato storage consultant, and Potato Solutions Ltd Director, also has extensive experience with Argos. “Over the last season, ARGOS tted very well into my storage management. e product shows good e cacy in store and controls sprouting within a speci c range,” he said. “With the new oil sprout suppressants, good air ow is fundamental to provide that full coverage of a contact kill. Moisture, condensation, and damp refrigeration coils can cause ‘crop scorch’. Refrigeration coils on certain units are narrow, so cooling and fall out has been seen on the tops of crops. “All these risks I reduce by good store practices before and during applications. Certain varieties and stores had a eld MH application followed by only one application of ARGOS and left the store in April without sprouting. Fry colour is unaltered during the season which for certain end users is critical. Where my customers require a minimal harvest interval for exible marketing it ts well. e ability to ‘sit and wait’ for movement rather than proactively treat, can also be advantageous and save money in shorter term storage. I will continue to use ARGOS again this season and be mindful as with any chemical of its usage.” ARGOS is applied at a rate of 100ml per tonne of potatoes and a 21-day minimum interval must be observed between applications. e frequency of multiple applications is dependent on the susceptibility to sprouting. For best results carry out regular inspections to spot the break of dormancy. Although much larger sprouts have been successfully controlled, the best control and shortest intervals come from timing the fog to when 20% of tubers have the ‘white points’ of new sprouts visible. Every combination of store, stacking pattern and ventilation system is unique but one objective is true for all operations and that is to start with potatoes and structures at the same temperature and to maintain a gentle and uniform ow of air during treatment for improved e cacy and to avoid condensation. Fans should run for 24 hours prior to fogging with the relative humidity controls switched o . Fans should deliver a uniformmovement of air to all parts of the store during fogging and steps should be taken to avoid jetting of the air ow or short-circuiting leading to over or under dosing. Energy costs prompt reconsiderations ARGOS can be applied up to nine times a season and be used right up to 48 hours before leaving storage, giving good shelf life to a fresh product and very useful when unloading date is uncertain. e contact nature means no unnecessary applications – growers can save money by waiting until dormancy break before making the next application. It can also be used in boxed or bulk situations, in all varieties for chipping, crisping and fresh markets, and is exible for use in a programme with other sprout suppressants such as following eld applied maleic hydrazide. e fog is light and dry and readily reaches all parts of the store, the manufacturer states, adding that the vapour disappears within a few days and produces no taint or smell on the treated potatoes or store structure. High energy costs are causing some growers for the fresh market to examine how they store potatoes. Normally they rely on cold temperatures of 2.5-3.0°C to do most of the work- particularly for short term storage - but some will now be looking at storing at slightly higher temperatures of around 4°C with the possible use of an in-store product when dormancy breaks. Work done at AHDB Sutton Bridge in the past has shown a minimal e ect on tuber diseases and some signi cant energy savings. “The ability to ‘sit and wait’ for movement rather than proactively treat, can be advantageous and save money in shorter term storage.” Tim Kitson, Independent Potato Storage Consultant STORAGE