Impact of rice harvest on diapausing yellow stem borer, Scirpophaga incertulas (Walker) populations [in Bangladesh].
1991
Islam Z.
The effect of transplant aman and deepwater rice harvest on diapausing populations of rice yellow stem borer, Scirpophaga incertulas (Walker), were studied during 1983-85 in Bangladesh. Harvesting of deepwater rice removed only 12% of borers from the field with straw of 83 cm long but had no effect on borers in transplant aman harvested at 15 cm height. It might be possible to harvest deepwater rice straw length from 83 cm to 100 cm without affecting the straw quality as cattle feed, but reduction would not be possible by the manipulation of harvested straw length in transplant aman rice. During the winter, S. incertulas remained in the stubble on an average 110 cm away from the base of deepwater rice but below the soil surface in transplant aman stubble. The present practice of destroying most deepwater rice stubble by burning during March-April has little effect on borer populations as moths emerge earlier (February- March). To derive benefit, stubbles are to be destroyed in a large scale by the end of January. An easy and economic method of destruction of short and isolated transplant aman stubble is needed.
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