Phase of Overhead Flooding Damage during Maturation of Rice

벼 성숙기 침관수 피해양상

The typhoon and flooding injury in rice were investigated both the region of downpour at the middle of August and the region of typhoon 'Yanni' at the late of September, 1998 in Kyongbuk provincial of Korea. More than 10% of rice stem were buried by soil inundation, the heading was delayed and the high node tiller was brought out. Yield components were deteriorated and yield was reduced. As the clay in the muddy water was attached on grains of rice, the yield was greatly reduced by reason of low grain filling ratio and polished rice ratio. The injury of muddy water was less at yellow ripening stage than at early ripening stage. On the other hand, the muddy water injury was reduced by the fungicide 'Benomyl' and 'Daconil' treatments. The degree of lodging according to varieties and ripening stages was not made a great difference, while the lodging was mainly occurred in the early transplanting time. In a week after lodging, viviparous spikes were occurred in almost all varieties, the degree of viviparity was shown highly in order of early maturing, middle maturing and late maturing varieties in the field as well as in laboratory test. The viviperous spikes were greatly occurred in the lodging toward hill space within row than row space because the more grains were touched on the ground.

'98년과 '99년의 집중 호우시 침관수 피해지역과 태풍 피해지역을 대상으로 벼 생육 실태를 조사한 결과, 벼 감수분열기 토시유입에 의해 지상부의 10%이상이 매몰되면 출수가 지연 되고 고위분얼이 발생하며 등숙비율이 불량해져 수량이 감소하였다. 출수후 탁수가 관수되어 이삭에 흙앙금이 부착되면 등숙비율과 정현비율이 낮아져 수량이 감소하였는데, 흙앙금으로 인한 피해는 등숙이 진전될수록 경감하였으며, 베노밀과 다코닐 처리에 의해 피해가 경감되었다. 벼 도복후 7일정도 경과하면 대부분의 벼 품종은 수발아가 발생하고, 수발아 정도는 조생종>중생종>중만생종의 순이었다.