Determination of toxicity of various preparative forms of pesticidal fungicides for nodule bacteria inoculants

All-Russia Research Institute for Agricultural Microbiology, Podbelsky Chaussee, 3, 196608, Pushkin, St. Petersburg, Russia

^* Corresponding author: Laktionov@list.ru

Abstract

The aim of our study was to determine the effect of fungicide formulation, brand of fungicide, its concentration in the solution, holding time and temperature regime of the solution on the number of survivors of nodule bacteria of soybean, lupine, peas and lentils in a solution. Bacterial suspensions of soybean nodule bacteria (Bradyrhizobium japonicum 634b), lupine (Bradyrhizobium lupini 367a), pea (Rhizobium leguminosarum 261b), and lentils (Rhizobium leguminosarum 712) were studied. Wetting powders Benomil (active substance benomil 500 g/kg, LLC “Soyuzagrohim”, Russia), Benorad (active substance benomil 500 g/kg, JSC “August”, Russia) and Fundazol (active substance benomil 500 g/l, LLC “Agro-Kemi”, Russia) and concentrates of suspension Maxim KS (active substance fludioxonil, 25 g/l; “Syngenta International AG”, Switzerland), Protect KS (active substance fludioxonil, 25 g/l; LLC “Agro Expert Group”, Russia), Protect Forte VSK (active substance fludioxonil, 40 g/l + flutriafol, 30 g/l; LLC “Agro Expert Group”, Russia) were studied as fungicidal disinfectants. Compatibility was determined after the preparation of tank solutions of biological products and fungicides, followed by an assessment of the percentage of surviving rhizobia depending on the brand of fungicide, its concentration (10 and 20%), the holding time of the solution (2, 4, 8 h) and the temperature regime of the solution (2-5, 16-18, 27 °C).