Abstract

The present investigations on Alternaria leaf spot of cabbage caused by Alternaria brassicicola (Schw.) were undertaken with regard to occurrence, identification, pathogenicity, epidemiology and management of the Alternaria leaf spot through chemical and non-chemical methods. Pathogenicity tests was used to confirm the pathogenicity of fungus which was isolated from leaves. In dual culture test of bio control microorganisms with Alternaria brassicicola showed that Trichoderma harzianum had more mycelia growth inhibition of pathogen was 40% inhibition over control B. bassiana and T. polysporum was proved to be second best BCAs which inhibit the growth percentage. By using different fungicides, management of Alternaria leaf spot were done and epidemiological data was collected. In-vitro evaluation of fungicides against Alternaria brassicicola showed that at 500ppm of all fungicides were effective and higher gave 100% inhibition. But 500ppm is quite environmental friendly and disease killer too. In-vitro evaluation of different plant extracts against Alternaria brassicicola showed that neem and garlic extract showed better results as compared to others. The epidemiological studies revealed that moderately low temperature coupled with wet humid conditions prevailing during cropping season favor the rapid Alternaria leaf spot development on cabbage crop. The study further indicated the positive correlation of the disease progression with rainfall and relative humidity where in these meteorological parameters contributed to the extent of 99.99% towards the development of Alternaria leaf spot.

Key words: Cabbage, Alternaria leaf spot

Reference

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