Effect of Seeding Seasons of Rice Varieties on the Occurence of Sheath Blight

수도품종(水稻品種)의 파종기(播種期) 이동(移動)이 문고병(紋枯病) 발생(發生) 소장(消長)에 미치는 영향(影響)

This study was done to find out the effect of seeding seasons of rice varieties on the occurence of sheath blight caused by Corticium sasakii. The results obtained are summarized as follows; 1. The percentage of infected stems and susceptibilities to sheath blight wered ecreased as the transplanting dates were delayed. 2. The susceptibilities to sheath blight of early maturing varieties were high, medium maturing varieties were intermediate and late maturing varieties were least. 3. The percentages of infected stems of Indica X Japonica varieties checked on 28th July were lower than those of Japonica varieties, but the susceptibilities were not significant between them. 4. At all varieties, highly significant correlation was recognized between the susceptibilities and the heading dates. Also relatively high correlation was appeared between the susceptibilities and the accumulated temperatures from 10 days before heading date to 30 days after it. This indicates that the susceptibility was much influenced by high temperature of the latter part of the rice plants growth.

수도품종(水稻品種)의 파종기(播種期) 이동(移動)이 문고병(紋枯病) 발생(發生)에 미치는 영향(影響)을 조사(調査)하였던 바 다음과 같은 결과(結果)를 얻었다. 1). 이병경률(罹病莖率) 및 피해도(被害度)는 이앙기(移秧期)가 늦을수록 피해(被害)가 적었다. 2). 조생종(早生種)의 피해도(被害度)가 가장 크고 다음이 중생종(中生種)이며 만생종(晩生種)이 가장 적었다. 3). 7월(月) 28일(日) 조사(調査)한 이병경률(罹病莖率)은 통일계(統一系) 품종(品種)들이 Japonica계(系) 품종(品種)들보다 낮았으나 피해도(被害度)에는 유의성(有意性)이 없었다. 4). 피해도(被害度)는 출수기(出穗期)와 높은 상관(相關)을 보이고 있으며 이는 출수전(出穗前) 10일(日)부터 출수후(出水後) 30일(日)까지의 적산온도(積算溫度)와도 높은 상관(相關)을 보이고 있어, 수도생육후기(水稻生育後期)의 고온(高溫)이 문고병(紋枯病) 피해도(被害度)에 크게 작용(作用)하고 있음을 알 수 있다.