dc.description.abstract |
Lowland rice ecosystem in India is infested with complex weed flora including semi-aquatic and aquatic
weeds. Recently weeds having mimics with rice, perennial and other weeds which propagate by
vegetative means are emerging as major threat. Weeds cause yield losses from 15 to 76% in rice crop.
Besides, weeds remove about 21-42 kg N, 10-13.5 kg P and 17-27 kg K/ha in transplanted rice. Research
on weed management in lowland rice in India has been reviewed in this paper with respect to weed flora
and their impact, biology and ecology of weeds, weed management methods and future thrust areas of
research and management. The weed flora in lowland rice is very much diverse and dynamic over times
and places. Very limited information is available on biology and ecology of major weeds. Studies have
been carried out on cultural, manual, mechanical, chemical means of weed management. Shortage of
labours, lack of suitable weed control implements and problem of specific weeds have compelled the
farmers to think for alternative strategies and herbicides have been the obvious choice to the farmers.
Many herbicides either alone or in combinations as ready or tank mixed have been recommended in India.
Studies on integrated weed management have also been undertaken. But majority of researches focused
on herbicide based IWM. Future research and weed management in lowland rice should be focused on
ecophysiology and biology of major weeds, HR genetically modified rice, integrated weed management,
exploring biocontrol agents and screening and use of allelopathic and weed competitive rice cultivars. |
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