Harnessing the Antifungal and Antinemic Potential of Trichoderma in Integrated Crop Management System for Mitigating Fungal Nematode Complex in Cucumber

Abstract

The fungal saprophyte Trichoderma is ubiquitous in nature. This micro fungus plays a macro role in the suppression of soilborne fungal pathogens and nematodes infecting crop plants. Being a potential producer of hydrolytic enzymes and cellulases it colonizes the crop plants both at rhizosphere and spermosphere. Colonization by this unique fungus helps in preventing the entry of inimical microbes and nematodes infecting crop plants. Increase in the area under protected cultivation of vegetable crops has increased the outbreak of fungal nematode complex. Among the different vegetable crops, cucumber is an important vegetable crop cultivated across the globe. The area under protected cultivation of cucumber in India is being increased year after year. Continuous cultivation of cucumber for more than 2–3 years predisposes the crop for the infection of Fusarium nematode complex and thus becomes as a challenging task in the cultivation of cucumber under open field and protected conditions. However, judicious use of Trichoderma under integrated crop management will pave the way for successful cultivation of cucumber. 486 Trichoderma produces hydrolytic enzymes, such as glucanases and chitinases. These enzymes interact with Fusarium and Meloidogyne incognita and thereby suppress fungal nematode complex. This microbe not only stops with it, but also produces an array of volatile and nonvolatile organic compounds of antimicrobial in nature. In addition, it also secretes ceratoplatanin-like small molecules with antimicrobial nature. Further, Trichoderma complements the crop growth through the production of growth hormones that in turn alters the root and shoot architecture of cucumber and thus results in enhanced yield and suppression of fungal nematode complex. Delivering of Trichoderma through seed treatment and soil drenching at periodical intervals aids in the proliferation of the antagonist in rhizoplane and serves as a line of control to prevent the ingress of fungal nematode complex into plant system. Fusarial wilt of cucumber is effectively managed under protected cultivation through biopriming and soil application of Trichoderma. Combined application of talc formulation of Trichoderma spp. viz., T. virens TRI 37, T. harzianum TRI 35, T. harzianum TRI 36 through seed treatment @ 10 g/kg and soil application 2.5 kg/1000 m 2 reduced the disease incidence and promoted plant growth, increased the yield, and number of fruits in cucumber in comparison with control. Hence, the application of Trichoderma spp., not only suppresses the biotic stress but also indirectly complements for the production of residue free produces.