Expediency of protecting corn crops from progressive phytophages

Abstract

Monitoring of phytophages of corn crops in the conditions of Kabardino-Balkaria in the steppe arid zone for 2000–2021 was carried out in dynamics. It was noted that climate change in the direction of warming and significant increase in the areas of corn crops changed the phytosanitary situation, which led to the formation of foci of high numbers and harmfulness of cotton budworm. Control agents against cotton budworm and corn borer from different groups of chemical and biological compounds were studied. Protective measures were planned and implemented based on the predicted and actual phytosanitary situation in order to obtain ecologically cleaner and biologically nutritious grain products. Based on long-term observations, the outbreak of cotton budworm and corn borer was found to be periodic for 5 ± 1 years. This will allow timely spraying in years of maximum outbreaks of these pests. Determination of biological efficacy and competent rotation of the group of chemical insecticides will reduce their resistance to progressive pests on corn crops. Values of biological efficiency of insecticides in the variants of Voliam Flexi, SC and Avant, EC preparations corresponded to 97.1 and 95.6 %. The economic efficiency of the insecticides was evaluated by grain yield increment, where Voliam Flexi, SC, Avant, EC and Lepidocid, SC and had the values of 1.1; 1.0 and 0.5 t/ha, respectively. Long-term studies have established that yields depend on the degree of damage to cobs and corn grain by cotton budworm caterpillars. The reserve of significant increase of corn grain yield by 0.5–1.1 t/ha is the use of effective insecticides of chemical origin with low rates of consumption (Voliam Flexi, SC, Avant, EC). It has been revealed that 2-fold spraying with bioinsecticides Lepidocid, SC and Bioslip BT, P on the beginning and mass hatching of caterpillars significantly reduced the harmfulness of these pests, the biological efficiency of which amounted to 77.9 and 73.5 %, respectively.