Efficiency of insectofungicide dressing agents in suppressing potato rhizoctoniosis in the Novosibirsk region

The scientific research aims to establish the effect of modern insectofungicides Prestige and Respect on the development of potato rhizoctoniosis in agroecosystem crops in the region. The authors evaluated the effectiveness of the preparations under the conditions of production planting of potatoes in JSC “Sea Fields” during the period from 2015 to 2020. Under farm conditions, seed tubers are heavily (on average 38.5%) infested with sclerotia of the fungus R. Solani. Such requirements ensure that the pathogen is transmitted with the planting material yearly. During the study, the authors found that seed dressing reduced the infestation of tubers with the sclerotia form of the rhizoctoniosis pathogen by a factor of 4, thereby ensuring the interruption of the epiphytotic process. Insectofungicides protected potato seedlings already in the early plant growth and development stages. Insectofungicides reduced the number of dead potato seedlings in the field from 8.5% to 0.13%. Rhizoctoniosis in this farm developed on stalks in the form of an epiphytosis. Without seed tubers dressing, the prevalence of rhizoctoniosis was 72% to 88%. And the development of rhizoctoniosis disease was 27.1%, reaching almost 40% in some years. With the application of dressing, the growth of rhizoctoniosis on the stolons decreased by three times and did not exceed 8.8%. The number of damaged stolons was reduced by 2.2 times, and fallen stolons by 2.3 times. Introduction in the technology of growing potatoes dressing of seed tubers by insectofungicides allowed to reduce the total score of plants affected by rhizoctoniosis by 6.8 times. At the same time, the protective effect of insectofungicides Respect and Prestige was identical. The biological efficacy of insectofungicides ranged from 54.9% to 98.8%, while the economic efficiency was 17.7% to 24.2%.