Antagonistic Activity of Fructoplane Yeast Against Ulocladium Rot of Papaya

Debaryomyces hanseni zopf isolated from the fructoplane of appleswere found to be effective as biocontrol agent against rot of papaya caused byulocladium. chartarum (pr.) simm. the ability of d. hansenii to preventinfection of u. chartarum was lost when the antagonist cells were killed byautoclaving. cell free culture filtrates of antagonist were unable to preventdisease incidence. efficacy of sodium bicarbonate, sodium chloride, sodiumcarbonate (0.25%, 0.5% and 1.0%) and calcium chloride (cacl2 0.25%, 0.5%and 1.0%) solutions alone or in combination with the application of biocontrolagent debaryomyces hansenii (106 and 109 cfu ml-1) were simultaneouslyevaluated for the control of ulocladium rot of papaya. fresh cells of biocontrolagent proliferated inside the wounds and their survival was not adverselyaffected by the presence of residues of calcium chloride salt. sodium carbonateadversely affected the growth of yeast cells in in-vitro and in-vivo experiments.sodium bicarbonate and calcium chloride also reduced the percent rot buttheir integration with biocontrol agent enhanced the activity of antagonist athigh levels as compared to the single treatments of salts and d. hansenii. theintegration of treatments is a promising approach to control the ulocladiumrot of papaya