ABSTRACT. Introduction of mycorrhizal associations is a complementary alternative to improve fertilizer absorption efficiency of black pepper (Piper nigrum Linn.

An experiment was conducted to evaluate different combinations of biofertilizer and biocontrol agents on the vegetative growth of nursery plants of black pepper (Piper nigrum L.). Treated plants showed a significantly higher (p<0.05) leaf area, shoot height, root volume, shoot dry weight and root dry weight compared to the untreated control. The highest leaf area of 244.47 cm 2 was recorded in black pepper plants treated with Trichoderma sp. and Pseudomonas fluorescens while the lowest (118.82 cm 2 ) was recorded in the untreated control. The highest root volume was recorded in plants treated with Trichoderma spp. The highest shoot height, shoot dry weight and root dry weight were found in plants treated with P. fluorescens. Results showed that the combination of above three organisms has not shown a significant impact on growth (p>0.05) than that of the respective individuals. As certain biological control agents may mechanistically be incompatible, one strain may interfere with the mechanism of the other. Hence, only the mixtures composed of mechanistically compatible strains can give better results in biocontrol and bio-fertilizer activities. The results of the experiment confirmed that black pepper plants treated with different biocontrol agents and bio-fertilizer showed a higher vegetative growth in the plant nursery.