INFLUENCE OF THE PROTECTION SYSTEM ON LIMITATION OF THE NUMBER OF MAIN PESTS IN CORN CROPS

Abstract

This article highlights the theoretical generalization and solution of the problem, which consists in the development and substantiated elements of the system of protecting corn from a complex of pests and controlling their number in the conditions of the Vinnytsia district, which is based on the clarification of the species composition of phytophages in corn crops, their harmfulness and limiting the number when applied insecticides for seed treatment and spraying of crops with chemical preparations. The species composition of the harmful entomofauna of corn was clarified and 32 species of insects from 7 orders and one species of mites were identified. The order was dominated by Coleoptera – 45,2% and Lepidoptera – 15,2%. Diptera and thrips were the least numerous in corn crops – 5,3%. The most numerous families in corn crops are determined to be weevils, weevils, lamellae, and leaf-eaters. It was established that the biggest threat to the seeds and seedlings of corn was the larvae of weevils (Elateridae) and the larvae of plate-bearded beetles (Scarabaeidae), and the most dangerous pest of generative organs during the years of corn research was the cotton bollworm (Helicoverpa armigera Hbn.). Therefore, the corn crop protection system was implemented to limit the number of the above-mentioned phytophages. The effectiveness of modern insecticides against the dominant pests of corn and optimized methods of their application were evaluated. It was established that the highest technical efficiency of insecticide poisons was noted in variants with poisoners Force Zea 280 FS (5,5 l/t) and Poncho 600 FS (2,5 l/t). 82,2% and 81,1% for whitefly larvae; Poncho 600 FS – 81,8% and 82,6%, respectively, while the density of pest larvae was almost 4.5 times higher than in the control, and the yield preservation was at the level of 0,69–1,19 t/ha . When testing insecticides against cotton bollworm caterpillars on corn crops, the highest technical efficiency was provided by the insecticides: Koragen 20 hp. (0,15 l/ha) – 86,0% and Ampligo 150 ZC, FC (0.2 l/ha) – 80,5%. With the use of the investigated insecticides, the yield of corn exceeded the control. The saved yield was 0,23–0,32 t/ha.