Supplementing biocontrol agents with botanicals improved growth and yield of coriander (Coriandrum sativum L.) infected with Protomyces macrosporus Unger

This investigation was carried out to examine the effect of some biocontrol agents (Trichoderma viride, T. harzianum, Azotobacter chroococcum, Pseudomonas putida) and botanicals (Melia azedarach, Eucalyptus globulus, Calotropis procera) both alone and in combination on growth, yield and stem gall disease of coriander (Coriandrum sativum L.) caused by Protomyces macrosporus Unger in a pot experiment. Plants inoculated with P. macrosporus caused significant reduction in growth and yield attributes as compared to untreated control. Stem gall intensity was recorded 59% in plants treated with pathogen alone. The results revealed that, application of biocontrol agents / botanicals both alone and in combination caused significant reduction in stem gall intensity (20.33-84.82%) as compared to control. Among the tested biocontrol agents, T. viride was found superior in enhancing the growth and yield as well as reduction in stem gall intensity (44.37%). Application of biocontrol agents in soil supplemented with botanicals was found more beneficial in enhancing plant growth and yield attributes as well as reducing stem gall intensity (52.54-84.82%). Among various combinations tested T. viride + Melia azedarach and T. viride + E. globulus caused greater increase in plant growth and yield characters both in pathogen inoculated as well as uninoculated plants.