Effect of Biologically Active Bread Yeast on Controlling Meloidogyne incognita Infesting Green Bean and on The Yield Quantity and Quality

A biologically active compound, bread yeast containing the fungus Saccharomyces cerevisiae activated by adding sucrose, black honey and molasses was studied under field conditions. After fermentation, yeast was used at concentrations of 0.25, 0.50 and 1% for biocontrolling of Meloidogyne incognita (Kofoid White) Chitwood root-knot nematode infesting common bean cv. Paulista. All treatments significantly (P≤0.01 and 0.05) decreased M. incognita as indicated by the number of galls and egg-masses on roots. There is a negative correlation between the percentage reduction of the number of galls and eggmasses and different concentration used. One month after application, the highest concentration of yeast caused the highest percentage reduction of galls (66.7%) followed by the moderate and the lowest concentrations (55.6 and 44.4%, respectively) for yeast activated by sucrose. Whereas, yeast activated by black honey at the respective concentrations caused 77.8, 66.7 and 33.3% reduction in the number of galls. Yeast activated by molasses at the highest concentration caused the highest percentage reduction of galls (77.8%) followed by the other two concentrations (66.7%). After three months (at harvest), the same treatments behaved the same trend in reducing nematode parameters. Also, yeast activated by the different materials increased pod production quality (number and weight of pods) and quantity (proteins and carbohydrates) and positively correlated to the tested concentrations. It is concluded that yeast concentrations increase plant nutrition in addition to nematode management.