Evaluation of the Effects of Plant Growth Promoting Rhizobacteria (PGPR) on Yield and Quality Parameters of Tomato Plants in Organic Agriculture by Principal Component Analysis (PCA)

Our research was carried out to determine the effects of plant growth promoting rhizobacteria (PGPR) on the yield and quality parameters of tomato plants in organic farming conditions. In our study, Bacillus megaterium M-3, Paenibacillus polymxa, Burkholderia cepacia, Azospirillum sp-245 bacterial strains were applied by three different applications methods such as to the soil, root region and leaves. The research was carried out as field experiment in 37 plots and 10 plants per plot. As a result of the study, it was determined that different PGPR applications significantly affect the yield and quality parameters of tomato plant in organic agriculture. When the results were evaluated, the highest yield was obtained as 1533 kg da(-1) with foliar application of B. megaterium M-3 bacteria. B. megaterium M-3 bacteria application to leaves increased that yield by about 20% compared to the control. It was determined that the bacteria applications did not have any significant effect on fruit size, fruit width and fruit weight. However, PGPR applications increased the amount of plant nutrients in the leaf, and pH, soluble solid contents (SSC), the rate of titratable acidity and the vitamin C values in the fruit. In conclusion, some PGPR bacteria as B. megaterium M-3, P. polymxa, B. cepacia, A. sp-245 increased the yield of the product and have a positive effect on quality parameters. As a result of the PCA (principal component analysis), PC1 alone explained 35% of the total variance and PC2 explained 24%. PC1 was found to be associated with soluble solid matter, vitamin C, titratable acidity, pH and EC, PC2 was found to be fruit yield and marketable yield, and PC3 was found to be scrap yield and marketable yield ratio.

Automated summary

The research showed that different plant growth promoting rhizobacteria (PGPR) application methods significantly affect the yield and quality parameters of tomato plants in organic farming, with foliar application of B. megaterium M-3 bacteria resulting in the highest yield increase of around 20%. PGPR applications also led to an increase in plant nutrients and certain quality parameters in the fruit.