Abstract
Effect of dried pine (Pinus roxburghii) needles, and fresh leaves and twigs of eucalyptus (Eucalyptus longifolia), lantana (Lantana camara), eupatorium (Eupatorium adenophorum), Persian lilac (Melia azadirach), and pea (Pisum sativum) crop refuse as mulch and okra (Abelmoschus esculentus), maize (Zea mays), sorghum (Sorghum bicolor), and pearl millet (Pennisetum americanum) as intercrops on the management of disease in the field was evaluated, and the effect of their extracts and leachates on zoospore germination inhibition of the pathogen in vitro was assessed. Aqueous leaf extracts and leachates of all the test plants caused significant inhibition of zoospore germination. Aqueous extract of Persian lilac and leachate of eucalyptus were found to be highly effective and inhibited zoospore germination of P. colocasiae by >94.0%. Mulching delayed the appearance of disease by 5-9 days over unmulched plots. Mulching with leaves and twigs of eupatorium was found to be highly effective in delaying the disease, in reducing the terminal disease severity, and enhancing the corm yield, whereas, that with pea crop refuse was least effective. Intercropped taro had less disease than the pure crop. Two rows of all intercrops except okra when grown alternately with one row of taro, were found to be more effective than a single row of intercrops in reducing the disease. Single and double rows of okra as intercrop was ineffective in managing the disease. Amongst the different intercrop-taro combinations, taro intercropped with sorghum and pearl millet as a single row or double rows were more effective in managing the disease.
