Preharvesting desiccation of sunflower as the important tool against white and gray rots

It was determined that in the areas where the amount of sunflower plants, infected by white and gray rot, is 10-15 % or more, the desiccants treatment should be carried out after 35-40 days of mass flowering but when the seeds moisture is up to 40 %, which is 3-5 days earlier than the optimum date. The desiccants cause the drying of seeds and plant tissues, creating unfavourable conditions for the diseases development, since the pathogen does not develop on a dry substrate. Depending on the weather conditions after treatment of plant variety and hybrid with application rate of Reglon Super of 1.5-2.0 l/ha, the drying process takes 5-8 days. However, for the hybrids like Kubansky 930 and Kubansky 931, and variety Buzuluk, the plant drying is going slowly in the initial period of up to 3 days, then, it accelerates in the next 5-7 days, and at the time of harvesting the seeds moisture is up to 7-8 %, for the early-season hybrids (RG 64A-03, Triumph, etc.) this process begins from the first days after treatment. The tank mixture of desiccants Reglon and Hurricane provided moisture decrease of sunflower seeds to harvesting moisture for 2-3 days later.