Application of Associative Rhizobacteria for Increasing the Soft Wheat Productivity and Reducing the Diseases Harmfulness

The search for environmentally friendly biological approaches to increase the productivity and resistance to phytopathogens of wheat is an urgent task for agriculture. For this purpose, the effect of plant growth-promoting rhizobacteria on yield and disease development of soft wheat was studied.

Two soft wheat varieties (Trizo and Sudarynya) were inoculated with Bacillus subtilis 124-11, Pseudomonas fluorescens SPB2137 and Sphingomonas sp. K1B under field conditions during 2017-2021 years. Wheat development was monitored at different stages using a set of indicators characterizing morphological traits and yield structure. Susceptibility of plants to root rot pathogens and leaf diseases (brown and yellow wheat rust, powdery mildew, septoria-pyrenophorous spotting) was analyzed using a number of phytopathological indicators.

The maximal increase in yield by 1.14 g plant^-1 and 0.87 g plant^-1 was revealed after treatments with B. subtilis 124-11 and Ps. fluorescens SPB2137. The minimal ecological variation in wheat productivity elements was observed when B. subtilis 124-11 was used. The bacteria reduced plant damage caused by helminthosporiotic root rot, leaf-stem infections, yellow and brown rust and septoria-pyrenophorous spotting. The effects of bacteria on wheat growth and biocontrol of phytopathogens significantly varied depending on meteorological conditions and plant cultivar.