Bio-efficacy of plants extract against Alternaria brassicicola causing Alternaria leaf spot of cabbage

Abstract

Cabbage (Brassica oleracea) is most important vegetable crop and several bacteria, fungi and virus infect it and cause disease. Alternaria leaf spot of cabbage is very worst disease and is distributed worldwide in all cabbage growing countries. The growth inhibition of mycelium of Alternaria brassicicola was tested by treatment of culture by five botanical extracts viz. Azadirachta indica, Capsicum annum, Calotropis giganta, Barbadoes aloe, Aegle marelos and compared with control culture. These botanical extracts were added to the culture media at two concentration viz. 15 % and 25 % and tested by poisoned food technique. Neem and chilli plant extracts were found highly effective against pathogen at both 15 % and 25 % concentration and mycelial inhibition was recorded 68 % at 25 % concentration. Another two plant extracts Aloe vera and madar were also found to be effective against pathogen and both showed 55.33 percent inhibition at 25 % concentration. Minimum mycelia inhibition was recorded from Bel with only 37.77 percent inhibition at 25% concentration. Presently many farmers are using chemicals for control of Alternaria leaf spot of cabbage however, they cause health hazards. Therefore, this investigation will be helpful to the farmers for selection of suitable plant extracts, used as a control of Alternaria leaf spot of cabbage.