Bacterial antagonists Bacillus sp Q3 and Pseudomonas chlororaphis Q16 capable to control wheat powdery mildew in wheat

This paper outlines effects of the usage of two plant growth promoting (PGP) strains: Bacillus sp. strain Q3 and Pseudomonas chlororaphis strain Q16 trough vegetative experiments, performed in semi-controlled conditions on acid soils (Lessivated Cambisols). The studied parameters were chemical properties of soil and PGP effects of strains and their mixture on two wheat (Triticum aestivum L.) cultivars - NS 40S and CCB Ingenio. The seeds treatments with Q3 reduced the occurrence of Blumeria graminis f. sp. tritici natural infection only on CCB Ingenio (46.1%). The additional foliar treatment with Q3 decreased disease incidence (DI) 76.22% (CCB Ingenio) and 75.87% (NS 40S). Reduced initial DI of 77% caused Q16 solely or mixed with Q3 on cv. NS 40S and additional foliar treatment reduced DI to 16.30% (CCB Ingenio) and to 6.35% (NS 40S). The mixture of strains decreased DI to 14.69% (CCB Ingenio) and to 6.09% (NS 40S). Despite the effects of applied strains on wheat growth were affected by limited production capacity of soil and the extreme climatic conditions, SDW of inoculated cultivars were increased by 17-39% (NS 40S) and 35-43% (CCB Ingenio). The N increment ranged from 59% (Q3) to 152% (Q16) for cv. CCB Ingenio. Finding that the seeds treatments improved the plant biomass and N content (Q16) and decreased powdery mildew DI, we can recommended application of Q16 strain as biofertilizer for both wheat cultivars. Depending on wheat cultivar, the additional foliar treatments to prevent powdery mildew infection will be set up for further trial