Entomopathogenic biopesticides - an alternative increasing the adaptability of plants to stress impact and eco-friendly source for the control of pests

Abstract

The aim of the work was to establish the possibility for application of entomopathogenic strains Bacillus thuringiensis ssp. kurstaki (Bt) and Bacillus thuringiensis ssp. thuringiensis (BT) in a tank mixture for spraying. For this purpose, the effect of the recommended and half concentrations of para-aminobenzoic acid (PABA) on the above-mentioned bacteria colonies was examined in vitro. Bacteria were cultivated in liquid mineral nutrient medium for 48 hours at 290C to the titer of 109 CFU/ml. The suspension was inoculated on the solid CGA nutrient media in Petri dishes. After bacterial cultures had grown for 24 hours, sterile disks (five disks per three Petri dishes) impregnated with biologically active substance emulsions were placed on their surfaces. After a week of incubation, the interaction of the studied concentrations of para-aminobenzoic acid (PABA) with bacterial culture was recorded. Bacterial growth inhibition zones were not found. This allows to assume that it is possible to combine working solutions of bioregulators with bacterial strains suspensions and at the same time to reduce the para-aminobenzoic acid (PABA) after effect.The similar results have been reported for B. thuringiensis mixtures with the pesticides Sumi-Alpha, Regent, Decis and Pseudomonas sp., Bacillus sp. with the pesticides Ridomil, Quadris, Raxil and Colfo-Super (Адрианов Ф.Д., 2011; Попов Ю.Б., 2008; Войтка Д.В.,2018).