Role of previous crops and mineral fertilizers in pathogenesis of potato black scab and crop productivity

Abstract

One of the main factors limiting the potato yield in Western Siberia is various crop diseases, among which soil and tuber infections hold a special place. The sore issue in potatoes production is black scab. The economic significance of this disease is estimated at 50 % yield loss during the growing season. The results of analyzing the effect of previous crops (potatoes, oats and tendergreen) and mineral fertilizers (N40P40K80) on pathogenesis of black scab in potato plantations, and also crop productivity are presented in the paper. Evaluation of the used techniques effect on development of black scab was performed on natural backgrounds in conditions of forest-steppe zone of Priobye in the Novosibirsk region. The seasonal dynamics of the Rhizoctonia solani fungus in the soil has a characteristic increase in the number at the end of plants growing season. In the conditions of Western Siberia, in the course of pathological process of black scab, the soil infection (proportion of the factor effect from 50 % during the phase of full germination to 90 % to the flowering phase) plays the most important role. Oats and tendergreen had been affecting on the agent of black scab disease during two years after cultivation as a precursor, and oats affected the pathogen more strongly in the second year of potato cultivation. On average according to factors, oats and tendergreen with mineral fertilizers (N40P40K80) reliably reduce development of black scab on plants 1.1-1.3 times as compared to potatoes cultivated in monoculture, and mineral fertilizers significantly (1.3 times) increase the plants performance. The predecessors (on average) had practically no effect on this indicator. The yield of potatoes in monoculture and after oats is almost the same, and after tendergreen it is insignificantly higher (1.1 times). Mastering environmentally friendly technologies for protecting potatoes from soil and tuber infections and implementation of those into production will contribute to obtaining stable crops of a high quality culture, and, as a result, formation of efficient agro-industrial complex ensuring the country’s food security.