Mechanism and activity spectrum of microbiological preparation batsikol with phytoprotective action

Various groups of agents are involved in biological crop protection to control pests and diseases. Of them, Bacillus genus possessing activity against harmful insects and phytopathogens is most promising and widely used. In this, the biologicals based on Bacillus thuringiensis (Bt) dominate. More than 70 varieties of Bt have been identified. These bacteria can survive for a long time after treatment. Preparations based on three Bt serovars (A, B, C) are mostly used for insects’ biocontrol. Serovar A Bt subspecies can form crystal endotoxins which are active against Lepidoptera ; serovar B Bt subspecies attack the larvae of mosquitoes and black flies, and phytophagous Diptera ; and serovar C Bt subspecies are active against Coleoptera beetles. A new serovar F (fungi) of this bacillus was identified. Physiological and biochemical properties of Bacillus thuringiensis provide the assimilation of nutrient substrates and antibiosis against biocenosis partners. Batsikol, the biological preparation based on B. thuringiensis var. darmstadiensis (H 10) with entomopathogenic action, was created at All-Russian Research Institute of Agricultural Microbiology (St. Petersburg). Batsikol contains components of culture liquid, spores, insecticidal and fungicidal exo- and endotoxins, due to which it possesses multifunctional properties. The article presents the mechanisms of entomopathogenic and antifungal action of microbial preparations based on Bt. Results of testing Batsikol effectiveness against various pests and diseases in field trials and vegetation experiments are shown. Liquid form of biological product was used in the study (spore titer of 3.5½10 9/ml). Field and vegetation tests were carried out in 1994-2013 in different regions of Russia (Leningrad, Novosibirsk, Volgograd region, North Ossetia, Stavropol and Primorsky regions). Batsikol was sprayed against phytophagous pests on vegetating plants. The efficacy against pests varied from 50 to 100 %. Different modes of application against phytopathogen were tested according to the type of parasitism and environmental characteristics of fungi (i.e., spraying, irrigation, seed treatment). In field experiments the efficacy of spraying strawberry plants against gray mold was 60-74 %. Soil watering was used against Fusarium wilt on tomatoes and flax with efficacy of 74-87 % and 34-42 %, respectively. When seeds were treated prior to sowing the efficacy was 66-71 % in case of soaking barley seeds against root rot, and 40-45 % while soaking potato tubers against damping-off. Based on the tests conducted with Batsikol in different regions of Russia, the spectrum of its activities against wide range of phytophagous pests and pathogenic fungi was revealed on different crops. The obtained data expand the understanding of Bt biology and, in particular, the action spectrum against various pests and diseases dangerous for many cultivated plants. Presented materials allow considering Bacillus thuringiensis as the basis of microbiological preparations with a multifunctional activity. The obtained data will allow expanding the scope of its application, and it will help to improve ecological situation.