Fungal Flora of Solanaceous Vegetables in and around Yamuna Khadar Delhi Belt and Implication for Root-Knot Nematode Management

Yamuna Khadar Delhi belt faces serious pollution due to industrial effluents containing heavy metals and agrochemicals used by the farm growers in and around khadar region. In fact, the toxins adversely impacted soil biodiversity particularly beneficial mycoflora in these areas. In the present investigation, an attempt has been carried out to evolve growers' friendly IPM package by using vermicompost, neem oil seed cake, mustard oil seed cake and indigenous isolate as core component through 'field to lab' and 'vice-versal' studies. The aim of in vitro investigation was isolation and categorization of fungal flora recovered from solanaceous vegetable grown at Yamuna khadar, Delhi on the basis of their nature either toxic or egg parasitic against Meloidogyne incognita. The tested fungal species were Aspergillus niger, A. terreus, Trichoderma harzianum, T. viride, Fusarium solani, Rhizoctonia solani, Alternaria alternata, Cladosporium oxysporum, Penicillium crysogenum. The frequency of beneficial fungi particularly Trichoderma was very low in fields of Usmanpur, Mayurvihar phase II and Kalindi Kunj while Aspergillus niger and Fusarium solani were dominant in most of the soil and root samples of root knot affected tomato, brinjal and chilli. It was noticed that ignorant and non-traditional growers of Kalindi kunj were using wastewater of Abu Fazal drain for irrigation.However, the status of fungal flora was much better in solanaceous vegetable crops of Madanpur and Rajpura villages where traditional farmers are using bore wells for irrigation purpose. Trichoderma was most consistent fungus in healthy fields of tomato, brinjal and chilli crops in Madanpur and Rajpura. In vitro investigation clearly showed that Aspergillus niger has been discretely observed to be extremely toxic and showed remarkably high mortality against M. incognita in larvicidal and egg hatching inhibition tests with almost negligible percentage of egg parasitization. The second highest toxic nature was performed by Fusarium solani while T. harzianum was mild toxic in nature. These fungi characterized as toxic on the basis of their degree of toxicity. Interestingly, local isolate of T. harzianum showed dual nature, egg parasitic and mild toxic which proved an ideal biocontrol agent. In the present investigation,integrated approach of sustainable components viz. vermicompost, neem oil seed cake, mustard oil seed cake and local isolate T. harzianum showed outstanding performance in terms of plant growth parameters and reduction in root knot nematode M. incognita population at field level.