Aims To ascertain the effectiveness of Aspergillus niger, Trichoderma harzianum, Pochonia chlamydosporia, Bacillus subtilis and Pseudomonas fluorescens against rice root‐knot nematode, Meloidogyne graminicola , and to optimize their application methods. Methods and Results The relative effectiveness of five indigenous biocontrol agents (BCA) against M. graminicola on rice cv. PS‐5 was tested initially in pot culture. The BCAs, A. niger, P. chlamydosporia and P. fluorescens proved more effective, and significantly reduced the nematode disease. It is hypothesized that success of a biocontrol module may vary with the BCA and application methods. Hence, the effectiveness of the above three BCAs as well as seven different treatment schemes were evaluated in naturally infested farmer’s fields during two consecutive years. In nematode infested plots without any BCA treatments, terminal galls formed, and plants suffered a 19‐31% decrease in plant growth and yield. The treatments with P. chlamydosporia or A. niger through root‐dip (RD) plus one soil application (SA) at 15 days after planting were found to be highly effective against the nematode. Conclusions Relatively greater nematode control was achieved with root‐dip plus two soil applications (15 + 30 days after planting) but statistically the effect was on par with root‐dip + one soil application at 15 days after planting. These treatments significantly reduced galling (22–25%), egg mass production (21–29%) and reproduction factor (63‐70%) of M. graminicola , and subsequently increased the grain yield (11–21%). Significance and Impact of Study Application methods enhanced the effectiveness of biocontrol agents against M. graminicola . The root‐dip plus one soil application at 15 days after planting proved to be most effective treatment to control root‐knot disease in rice. Use of multiple treatments (root dip and soil application) appears cumbersome, but in view of effectiveness and limitation of chemical control in rice paddies, farmers may adopt the above module that may lead to 11‐21% yield improvement.

Fusarium oxysporum f.sp. lycopersici (FOL), the incitant of the Fusarium wilt of tomato, is a highly damaging and prevalent disease in the majority of tomato growing areas. Keeping into consideration of high disease occurrence and incidence of FOL in tomato crop, the present investigation was undertaken to develop an effective bio-management approach to combat this disease. Initially, the studies were conducted to evaluate six multi-facial biocontrol isolates of Trichoderma species viz., Trichoderma harzianum AMUTH-1, T. harzianum AMUTH-2, T. harzianum AMUTH-3, T. asperellum (= T. viride) AMUTV-1, T. asperellum AMUTV-3 and T. virens (= Gliocladium virens) AMUTS-1 against FOL in vitro. Among these antagonists, T. harzianum AMUTH-1 and T. asperellum AMUTV-3 exhibited the maximum inhibitory effect while T. virens AMUTS-1 was recorded as the least effective Trichoderma isolate against FOL in vitro. Interestingly, T. harzianum AMUTH-1 and T. asperellum AMUTV-3 were found to produce indole acetic acid, siderophore and possess high enzymatic activities (cellulase, chitinase, ligninase and protease) in vitro. Further, pot trials were conducted and the chemical fungicide, carbendazim was used to compare the effectiveness of Trichoderma isolates. Pot trials also verified the efficacy of T. harzianum AMUTH-1 with 9–28% enhancement in the plant-growth parameters and 15–21% biomass production, and 88% decrease in the soil population of FOL. The effect of T. harzianum AMUTH-1 was also at par with fungicides, carbendazim.