Determination of the effect of plant growth promoting bacteria (PGPB) on bread and durum wheat development, yield and yield components

This study was carried out at Siirt University Faculty of Agriculture, Department of Field Crops trial field and laboratories with 3 replications and 24 parcels according to randomized complete blocks trial design between 2017 and 2018 as two seperate experiments. Study was planned to determine the effects of previously identified Stenotrophomonas maltophilia TV14B (phosphate solubilizing),Bacillus atrophaeus TV83D (nitrogen binding), Bacillus-GC group TV119E (phosphate solubilizing),), Cellulomonas turbata TV54A (nitrogen binding) and combined effects of Bacillus atrophaeus TV83D and Bacillus-GC group TV119E on the development of Ceyhan-99 and Fırat-93 bread wheat cultivars. Plant height (cm), spike length (cm), number of tillers, number of spikes per square meter, number of spikelets per spike, number of seeds per spike, thousand grain weight (gr), grain yield (kg / da), biological yield (kg / da), hectoliter weight (kg / 100 l), and harvest index (%) were determined. At the end of the study; In Fırat-93 durum wheat cultivar; plant height was 68,2-74,10 cm, the spike length was 5,23-5,92 cm, number of tillers was 2,52-2,93, number of spikes per square meter was 291,7-450,0, number of spikelets per spike was 15,93-18,10, number of seeds per spike was 27,93-36,40, thousand grain weight was 43,88-47,99 gr, grain yield was 218,75-288,89 kg / da, biological yield was 565,97-756,95 kg / da, hectoliter weight was 74,13-77,60 kg / 100 l and harvest index was determined as % 32,91-40,16. In Ceyhan-99 bread wheat cultivar; plant height was 71,67-80,07 cm, spike height was 6,45-7,92 cm, number of tillers was 2,07-3,27, number of spikes per square meter wass 370-535, number of spikelets per spike was 14,43-17,57, number of seeds per spike was 25,63-33,63, thousand grain weight was 38,28-40,03 gr, grain yield was 256,95-360,00 kg / da, biological yield was 615,28-850 kg / da, hectoliter weight was 74,73-77,73 kg / 100 l and harvest index was determined as % 41,70-45,34. As a result, the highest grain yield in Fırat-93 durum wheat cultivar was obtained from full dose chemical fertilizer application (288,89 kg / da); while the highest grain yield (283,33 kg / da) in bacteria applications was observed from Bacillus atrophaeus TV83D, nitrogen-binding bacteria,the difference between these two was not significant, and this bacteria can be seen as an alternative to chemical fertilization. In Ceyhan-99 bread wheat cultivar, the lowest grain yield (256,95 kg / da) was obtained fromthe uninoculated and unfertilized control and the highest grain yield (360,00 kg / da) was obtained from full-dose chemical fertilizer application, The highest yield among bacterial applications was obtained from Bacillus atrophaeus TV83D, a nitrogen-binding bacteria with 319,45 kg / da, and the difference between them was statistically significant. In both cultivars the lowest grain yield was determined in untreated and unfertilized control applications. At the end of the study it is thought that Bacillus atrophaeus TV83D bacterial strain can be used as a microbial fertilizer because of its ability to increase grain yield significantly in both genotypes. Keywords: PGPB, wheat, yield, yield components.