Development, yield, and quality of melon fruit (Cucumis melo L.) inoculated with Mexican native strains of bacillus subtilis (ehrenberg)

Strains of Bacillus subtilis increase plant growth and yield. Consequently, the application of Mexican native strains of B. subtilis on greenhouse-grown melon (Cucumis melo L.) plants should induced a significant improvement on plant development and fruit quality. The objective of this study was to evaluate the effect of LAL-36, BEB-23, BEB-22 and BEB-13 B. subtilis strains, native to Mexico, on melon plant development and fruit quality. The strains were placed separately into the rhizosphere of melon plants under greenhouse conditions. Plants were grown in clinoptilolite type zeolite. Five treatments were evaluated: four inoculated with one of the four B. subtilis strains and one control without bacterial inoculum. A completely randomized design with nine repetitions was used in the experiment. The data were statistically analyzed with a one way-ANOVA and a mean comparison using the Tukey's test. The root wet and dry weight depicted a sustained tendency with the greatest values and with significant statistical differences with LAL-36 and BEB-22 strains. The greatest values for shoot dry weight were 164.76 g for the LAL-36 and 162.14 g for BEB-22. The highest value for root dry weight was 64.55 g with the LAL-36 strain. The greatest values in height and foliar area (482.22 cm² and 398.41 cm²) were observed in the plants treated with BEB-23 strain. Utmost fruit yield (97.76 t ha^-1) was observed in the plants inoculated with LAL- 36 strain; this strain also induced exceptional fruit quality, although the differences were lower compared to the other. The inoculation of B. subtilis LAL-36 strain on melon plants caused the most outstanding effects during the production of greenhouse-grown melon fruits, increasing the yield in 20 %. Therefore, using Mexican native strains of B. subtilis is possible to obtain high quality melon fruits with increased profits.