Antimicrobial activity of medicinal plants against Xanthomonas campestris pv. campestris causing black rot of cabbage

Abstract

Cabbage is considered as the fifth most important vegetable crop in India and major constraint in its production is black rot caused by Xanthomonas campestris pv. campestris (Xcc). The management of the disease is difficult and the chemicals are least effective and are hazardous. Hence, a study was carried to test the potentiality of few medicinal plant extracts against the pathogen as the effective ones could be exploited as an alternate, cheap and eco friendly method of management. The water extract from only two botanicals viz., Ocimum gratissimum and Tylophora asthmatica were effective in inhibiting the growth of Xcc. O. gratissimum extract showed highest inhibition zone of 29.33 mm at 1:0 dilution and had inhibitory effect upto 1:10 dilution with 22.33 mm inhibition zone. Alcohol extract of O. gratissimum was the most effective in inhibiting the growth of Xcc followed by Calotropis gigentea, T. asthmatica, O. sanctum, Nigella sativa and Ruta graveolens.