Pre-planting treatment of potato tubers with biopreparations in conditions of Central Yakutia

Abstract

The results of the study of the influence of pre-planting treatment of tubers with biopreparations based on Bacillus subtilis bacterial strains on the growth, photosynthetic activity of plants, disease damage and yield of the Yakutyanka potato variety under the conditions of Central Yakutia are presented. The experiment scheme included control (tubers without treatment), treatment of the tubers before planting with the biofungicide Phytosporin-M and the suspension of an equal ratio of B. subtilis TNP-3 and B. subtilis TNP-5 bacterial strains isolated from permafrost soils of Yakutia. It was found that treatment of tubers before planting with biopreparations accelerated sprouting by 2-4 days, increased biomass and photosynthetic activity of the plants (by 6-19%), the number (11) and weight (48–57%) of tubers, reduced the damage of the plants by a complex of diseases by 1.8–2.9 times and increased the yield by 7.4–8.8 t/ha (54–64%). The share of biopreparation influence in the variability of economically valuable indicators and yield was shown to be 45–96%, weather conditions 1–38%, factor interaction 1–11%. Significant positive correlation of the yield, number and weight of the tubers with the height, number and weight of the plants, leaf area, photosynthetic potential (r = 0.81...0.98), and negative correlation with rhizoctonia disease, potato scab, and common mosaic (r = –0.80...–0.96) were revealed. There was an inverse relationship between disease prevalence and indices of plant growth and photosynthetic activity (r = –0.33...–0.96). Damage by potato scab and rhizoctonia disease increases 1.4–1.8 times in arid conditions, while blackleg, rugose and common mosaic damage decreases 1.6–2.5 times. Regression equations were calculated, which allow to predict leaf area, photosynthetic potential and yield by plant mass promptly and with high accuracy (R2 = 0.85...0.95). When the bush weight in the flowering phase increased by 100 g, the leaf area of the plants increased by 2.3 thousand m2/ha, photosynthetic potential during the growing season by 120 thousand m2 · day/ha, and the yield by 9.7 t/ha. The difference between actual and calculated values amounted to 2.7–4.7%.