The efficacy of bioagents against Fusarium oxysporum f. sp. udum causing wilt disease of Pigeonpea

Fusarium oxysporum f. sp. udum is one of the most destructive soil-borne diseases of Pigeonpea. The main target of present investigation was to evaluate the antifungal activities of bioagents which can be used to control wilt disease of pigeonpea. The bioagents viz.Trichoderma viride, T. harzianum, T. hamatum, T. longibrachiatum, T. (Gliocladium) virens, T. koningii, Aspergillus Niger, Trichoderma lignorum,Pseudomonas fluorescens andBacillus subtiliswere screened in vitro for their antifungal activities against F. udum by using dual culture technique. Trichoderma viride was found most effective with least linear mycelial growth (10.50 mm). The second and third best antagonists were T. koningii and T. harzianum, which recorded less mycelial growth of 13.00 mm and 15.50 mm, respectively. They were followed by Aspergillus Niger, T. (Gliocladium) virens, T. hamatum, T. longibrachiatum, T. lignorum, Bacillus subtilis and Pseudomonas fluorescens. In field evaluation under normal soil and semi sick soil condition, Trichoderma viride was shown minimum wilt incidence i.e. 19.24 % and 37.92 % and recorded maximum yield i.e. 773.78 and 531.20, respectively followed by Trichoderma harzianum shown 21.75 % wilt incidence with 709.59 kg /ha yield under normal soil and in semi sick soil condition, 40.14 % wilt incidence with 510.84 kg/ha yield recorded. In various dosages of T. viride (15 g/kg seed) showed minimum wilt incidence i.e. 20.58, 37.22 and 61.25 %, respectively with maximum yield compared to other treatments i.e. 756.74, 508.18 and 316.51, respectively.