穗稻熱病引起水稻產量損失估計

Estimation of Rice Yield Losses Caused by Panicle Blast Disease

蔡武雄(W. H. Tsai)

《中華農業研究》 37卷1期 (1988/03) Pp. 86-90

https://doi.org/10.29951/JARC.198803.0009

摘要

稻穗受稻熱病菌(Pyricularia oryzae)爲害引起之產量損失，依稻穗受害程度分爲0（穗軸上有病斑，但稻穗未受害），1/3（稻穗1/3以上受害），1/2（稻穗1/2以上受害），2/3（稻穗2/3以上受害）及1（稻穗整穗受害）等不同等級時，在民國75年及76年第一期作分別在臺南縣白河鎮及嘉義分所試驗田以水稻品種臺農67號及臺農70號在早植期、中植期及晚植期之單穗穀重估計穗稻熱病引起之產量損失率(%)可以下式求得。產量損失率(%)=5n1，（整穗受害之穗數）＋3n2（稻穗2/3以上受害之穗數）＋2n3（稻穗1/2以上受害之穗數）＋0n5（稻穗2/3以上受害之穗數）＋2n3（稻穗穗軸上有病斑，但稻穗未受害之穗數）＋0n6（健康之穗數）／6N（調查總穗數）。穗稻熱病不同發病等級和產量損失率之關係爲Ŷ=-5.11+84.56X

並列摘要

Yield losses of rice panicles caused by Pyricularia oryzae was studied. Rice cultivars of Tainung 67 and Tainung 70 were cultivated during the first crop of both 1986 and 1987 at Pai-ho and Chia-yi experimental fields, respectively, under early, intermediate and late transplanting stages. The disease severity of the panicles infected by blast disease based on the grains damaged were divided into five degrees: 0 (panicle neck with necrotic lesions but rice grains without damage, 1/3, 1/2, 2/3 and 1 (more than 1/3, 1/2, 2/3 and total of the panicles were damaged). From the grain weight ratio under various disease severity on both cultivars at different transplanting stages and different locations, it indicated that the percentage of yield losses could be calculated by the following formula. Percentage of yield losses (%)=5n1 (number of panicles with all the panicle damaged) +3n2 (number of the panicles with more than 2/3 of the panicle was damaged) ±2n3 (number of the panicles with more than 1/2 of the panicle was damaged ) +1n4 (number of the panicles with more than 1/3 of the panicle was damaged) +0n6 (number of the panicles with necrotic lesions but rice grains without damage) ± 0n6 ( number of panicles healthy)/N. (total panicles investigated). The relationships between percentage of yield loss and disease scale of panicle blast was Ŷ=-5.11+84.56X.