Chemical control effectiveness against autumn cutworm and cotton bollworms in the tobacco agrobiocenosis

¹ Samarkand Agroinnovations and Research University, 141001, Samarkand, Uzbekistan
² Samarkand Regional Branch of the Research Institute of Plant Quarantine and Protection, Samarkand, Uzbekistan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

This article presents data on the chemical control efficacy against the autumn cutworm and cotton bollworm when cultivating the Virginia variety of tobacco under typical gray soil conditions of Urgut district, Samarkand region. Over the years of research, the most prevalent and dominant species were identified as the autumn cutworm (Agrotis segetum Denis & Schiffermüller, 1775), the cotton bollworm (Helicoverpa armigera Hübner, 1808), and the heart-and-dart moth (Agrotis exclamations Linnaeus, 1758). The degree of damage caused by the cotton bollworm to tobacco leaves was assessed at 3.1 points in 2019, 4.1 points in 2020, and 3.2 points in 2021, while for the autumn cutworm the corresponding values were 2.9, 3.5, and 3.7 points. In chemical control against the autumn cutworm, the highest biological efficacy was observed in the variant treated with Engeo 24.7% SC, reaching 96.6% by the 14th day after application. In the control of the cotton bollworm, the highest biological efficacy for all preparations was also recorded on the 14th day, with the Indox Super 20% SC preparation applied at 0.3 l/ha showing the highest efficacy at 93.7%. The correlation between the applied chemical preparations and biological efficacy for both pests followed a linear regression equation of the form Y = ax + b, with identical correlation coefficients of r = 0.98, indicating a strong relationship. Based on these results, an agrotechnological guideline was developed and recommended for chemical control: Engeo at 0.25 l/ha against the autumn cutworm, and Indox Super at 0.3 l/ha against the cotton bollworm.