DOI: n/a
Abstract
An experiment with the potato variety Nadehda grown according to the scheme for early field production with polypropylene (PP) cover was carried out in the period 2004-2006 with a N16P12K12 fertilization background at the Maritsa Vegetable Crops Research Institute – Plovdiv. Leaf fertilization with soliphid and potassium nitrate was applied during the vegetation period. The strongest attack by Phytophthora infestans (Mont.) De Barry) occurred in the uncoated control, which was related to the weather conditions during the period. A higher degree of infestation of black leaf spots (Alternaria solani Ell. et Mart.) was established in the variant with PP cover. The fertilization with КNO3 and soliphyd restricted the progress of the disease. The lowest density of adults and larvae of the Colorado beetle (Leptinotarsa decemlineata Say) was recorded in the variants with polypropylene cover and leaf fertilization with soliphid and КNO3. The two-factor analysis established that the systematic factor version (growing conditions) had a proven effect on the variability of the density of the potato beetle larvae (average number of plants).