The effect of the Pseudomonas fluorescens bacteria and substances of a stimulating nature on the productivity of the soybean plant and seed damage by pathogens

Abstract

Soybeans are a strategic leguminous crop for global agriculture and play an important role in ensuring food security in many countries. Therewith, biotic factors, in particular, pathogens prevent obtaining a rich and high-quality yield of the crop. Their control is conducted using various methods and technques. However, with an excessive increase in the use of chemical protective equipment, the environmental situation in agrocenoses becomes more complicated. Therefore, it is important to reduce the pesticide load in crop cultivation technologies. The purpose of the study is to assess the effect of the Pseudomonas fluorescens bacteria and stimulating substances on soybean plant productivity and seed damage by pathogens. The experiments were conducted in the conditions of the Ukrainian scientific-research station on plant quarantine of the Institute of Plant Protection of the National Academy of Agrarian Sciences of Ukraine. The soil of the experimental plot is grey forest heavy-loamy. The Ksenia soybean variety was used in the study. Field studies were conducted according to generally accepted methods. Soybean crops were sprayed during the growing season in the following periods: true three-leaf, flowering, and bean formation. For the treatment of soybean plants, a preparation based on the Pseudomonas fluorrescens bacteria with a titrant of 3x109 CFU/cm3 was used with a consumption rate of 5.0 l/ha per use in combinations with substances of stimulating action. Over the years of research, the amount of precipitation (in certain months of soybean vegetation) was higher than the average monthly perennial norm. Pre-harvest desiccation of crops was not conducted. Phytopathological examination of seeds obtained from soybean plants for various treatment options was conducted in accordance with DSTU 4138-2002. Studies show a positive effect of the drug based on P. fluorescens and substances of a stimulating nature on biometric indicators of soybean plants and their productivity. In particular, the weight of 1000 seeds in variants with spraying plants increased in the range from 16 to 66 g. Joint application on soybean crops of P. fluorrescens together with substances of the group of ammonium salts of dihydropyrimidine and stimulating substances provided an increase in the yield of soybean seeds up to 1.1 t/ha. There was also a decrease in infection of soybean seeds with pathogens of Fusarium, Alternaria and penicillosis – Fusarium oxysporum Schlecht, Alternaria spp., and Penicillium expanum Link fungi. The investigation of the immunoprotective and stimulating effects of combinations of biocomplexes is promising for the development of environmentally safe measures to increase soybean yield and reduce seed damage by pathogens