Ecological Studies on Rice Sheath Blight Caused by Rhizoctonia solani II. Forecasting and Control of Rice Sheath Blight

벼잎집무늬마름병의 생태학적연구 II. 발생예찰과 방제

  • Kim Chang Kyu ;
  • Min Hong Sik
  • 김장규 ;
  • 민홍식
  • Published : 1983.03.01

Abstract

To develop forecasting methods of rice sheath blight caused by Rhizoctonia solani, two rice cultivars Jinheung (Japonica type) and Yushin (Tongil type) were used from 1976 to 1981. Severity of rice sheath blight disease at maturing stage was estimated by top lesion height, percentage of top lesion height vs. plant height in July and lesion index on September 11. The relationship between top lesion height on July 11 and degree of damage at maturing stage for a cultivar Yushin was represented by the equation of Y=4.64x-13.2, and $r=.840^{**}$, where Y is degree of damage by shea4h blight at maturing stage and x is top lesion height on July 11. Considering the percentage of infected hills/stems was rapidly increased from July 11 to August 1, the most effective period and time for fungicide spray were considered July 15 and July 25 or July 25 and August 5.

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