Application of Biocontrol Agents and Plants Extract Against Fungal Phytopathogens of Vegetable Crops

The yield of vegetables is under threat due to climatic changes and resistance of pathogens against synthetic treatments and fertilizers. The soil-borne phytopathogens fungi and some climatic factors are responsible for decreasing the production of vegetables all over the world. In the present study, the vegetable plants showed symptoms of wilting, root-rot, stunted growth, chlorosis, blotch, etc. with soil collected from lower regions of Sindh, Pakistan. A total of twelve phytopathogen fungal genera Aspergillus, Alternaria, Cladosporium, Curvularia, Nigrospora, Drechslera, Fusarium, Rhizoctonia, Macrophomina, Penicillium, Sclerotium, and Rhizopus were isolated from the 80 samples of different vegetables including cabbage, Chilli, Cucumber, Okra and Tomato. But Aspergillus, Fusarium, Macrophomina, Alternaria, and Rhizoctonia were found dominant and recorded almost in all soil and root samples of vegetables. The infection was found due to several climatic factors including humid climate, the existence of moisture in the vegetable crop, the excess of water in the soil, transmission of infection by wind, gales and dust storms, packing, and the presence of moisture in storing units. For biological control and plant extract screening, two biocontrol fungal agents (Trichoderma harzianum, Paecilomyces lilacinus) and two plants leave extracts (Striga hermonthica, Ocimum basilicum) were applied in controlled lab conditions against the above-mentioned dominant phytopathogenic fungi. On the basis of this study, it is concluded that the leaves of S. hermonthica can be utilized as a biofertilizer in the soil. But it is necessary to need to extend this study and weed S. hermonthica should be studied furthermore before using it on large scale.