EFFECTIVENESS OF SOME PATHOGENIC CONTROL AGENTS AGAINST PESTS IN GREENHOUSE VEGETABLE CROPS

Abstract

Greenhouse tomato and cucumber are attacked by a great number of pests. The most frequently occurred pests are: greenhouse whitefly (Trialeurodes vaporariorum Westw.), cotton aphids (Aphis gossypii Glov.), tobacco and western flower thrips (Thrips tabaci Lindeman, Frankliniella occidentalis Perg.), cotton bollworm (Helicoverpa armigera Hb.) and two spotted spider mite (Tetranychus urticae Koch.). Plant protection products applied in practice are not always efficient enough due to arising of resistance to these products in the populations. Moreover their use could results in accumulation of residual amounts and environmental pollution. Recently a great interest to find alternative solutions for pest control is observed. Some viruses, bacteria and fungi which are pathogenic to the pests but safety for human, could be used. There are products with good efficacy, which are developed on this basis and applied for pest control.

Investigations for determining of the biological activity in the following products were carried out during the period 2016-2017 in the “Maritsa” Vegetable Crops Research Institute - Plovdiv: Naturalis (a. i. Beauveria bassiana strain АТСС 74040) at a dose of 100 ml/da, Rapax (a. i. Bacillus thuringiensis subsp. kurstaki strain EG 2348) at a dose of 100 ml/da and Helicovex (a. i. Helicoverpa armigera nucleopolyhedrovirus Hear NVP, DSMZ-BV0003 – 7,5 x 10¹² NPV/liter) at a dose of 20 ml/da. The product Naturalis at a dose 100 ml/da has a good effectiveness (over 75%) against greenhouse whitefly, cotton aphids, thrips, and movable forms of the two spotted spider mite in tomato and cucumber grown under greenhouses. The products Rapax at a dose of 100 ml/da and Helicovex at a dose of 20 ml/da have a good biological activity (E = 76,32% and E = 76,92%, respectively) towards to the larvae of the cotton bollworm in greenhouse tomatoes.