06-08-2013, 04:38 PM
Seed discolouration in rice grains in the intermediate zone of Jammu region Shahid Ahamad and Pawan Sharma
ABSTRACT
Rice (Oryza sativa L.) is one of the most important cereal crops of the world. About 90 per cent of rice produce in world is consumed only in Asia while China is the leading producer of rice (112.4 million tonnes per year) followed by India (87 million tonnes). India has largest area under rice (44.6 million ha.) cultivation in the world. In Jammu and Kashmir, rice is adopted and ascended as the most important cereal crop as staple food of the people, especially for the people of hills. In Jammu and Kashmir, the glume discolouration of paddy has perceived serious proportions both in grain and seed production programme in temperate ecosystem area, where it appears to be surpassing the importance of even previously known major constraints. The appearance of glume discolouration by various organisms before or after harvest, the extent of which varies according to season and also within the season on short, medium and long duration rice cultivars grown under rice growing domain of hills of Jammu region. Following fungi were found to associated with glume discolouration viz. Alternaria alternata and Helminthosporium oryzae caused ash grey and black discolouration in seed respectively, whereas due to Curvularia lunata and Fusarium graminearum, Fusarium moniliforme, eye shaped and light pink discolouration appeared in seed coat, endosperm and embryo of seed respectively. It is caused by complex of fungi with the species of Alternaria, Curvularia, Fusarium, Helminthosporium, Nigrospora, Phyllostic and Sclerotium.The fungi viz., Alternaria alternata, Aspergillus niger, Curvularia lunata, Fusarium spp. Helminthosporium oryzae, Nigrospora oryzae, Phyllosticta glumarium, Penicillium spp. and Sclerotium oryzae are attacked at booting, heading, milking and doughing stages of crop. The heading stage is found to be most vulnerable to grain discolouration.