Sunday, August 12, 2012
Columbia Hall, Terrace Level (Washington Hilton)
Fusarium oxysporum f. sp. lycopersici is a known pathogen of tomato plant, an economically important crop. Tomato yield is significantly reduced by fusarium wilt because it can destroy roots of tomatoes at growth stages. The study was conducted to assess the efficacy of antagonist fungi; Aspergillus niger, Penicillium citrinum, Penicillium sp., Trichoderma harzianum and cyanobacteria; Nostoc linckia and Phormidium autumnale for the management of wilt disease of tomato. Dual culture method showed that A. niger, P. citrinum, Penicillium sp. and T. harzianum inhibited the radial colony growth of the test pathogen. Minor to moderate zone of inhibition was observed with methanol extract of N. linckia and P. autumnale. GC-MS of these methanol extract showed the presence of several phenolic compounds. Seeds treated with N. linckia showed maximum increase in seed germination; followed by the seeds treatments of T. harzianum, P. autumnale, P. citrinum; minimum increase in seed germination was exhibited by A. niger treated seeds. Under pot conditions, the plant heights, fresh and dry weight of plants increased significantly (p ≤ 0.05) in all treatments except in P. autumnale amended soil. Similar results were also observed in chlorophyll (a+b) content of treated plants. Maximum control of wilt disease was observed with T. harzianum (44.4%) treated plants as compared to pathogen alone inoculated plants. Whereas, effectiveness of the other antagonists was recorded in the following order: A. niger (35.6%), N. linckia (33.3%), P. citrinum (24.4%) and P. autumnale (0.9 %).