(42(2):99-111)Varietal Difference in Yield and Yield Component of Rice in Response to Crop Seasons and Regions

本試驗以秈稉稻各十五個品種為材料，分別於臺北及臺中地區進行兩期作之田間試驗，調查各品種之抽穗期，並於成熟期測定產量與產量構成要素。目的在探討水稻品種於不同期作或地區間，對於產量及產量構成要素之表現狀況，及其品種間之差異，所得試驗資料，可供育種家之參考應用。 由試驗結果得知，秈稉型品種第一期作之產量高於第二期作，臺中大於臺北地區。產量及產量構成要素之期作間或地區間之差異，及品種間差異皆達1％水準的顯著性差異。其他之交感作用大部分亦極顯著。而產量構成要素方面除了千粒重之外，其餘與產量之變異並不一致。 不論期作或地區，表現高產品種為臺農67號（Tainung 67）、臺南5號（Tainan 5）、臺東29號（Taitung 29）、臺中秈10號（Taichung Sen 10）及嘉農秈11號（Chianung SEN 11），而期作性豐收之品種，第一及第二期作分別為臺農62號（Tainung 62）、高雄秈7號（Kaohsiung Sen 7）與豐錦（Toyonishiki）、臺農秈12號（Tainung Sen 12）這些品種大部分屬於穗數型。穗數之環境（期作、地區）間之品種相關係數皆為正相關，表示穗數對不同環境有較穩定性之表現。 Fifteen each of Japonica and Indica rice cultivars were grown under natural conditions in both the 1st and 2nd crop seasons at Taipei and Taichung. Heading data was investigated. Yield and yield component in maturing stage were also calculated, The purpose was to investigate the varietal difference in yield and yield compoment between crop seasons and between locations. Based on the information, it could be utilized as breeding programs. Experimental results indicated that grain yield was higher for the 1st crop than for the 2nd crop, and higher at Taichung area than Taipei area. Yield and yield component were all significant at 1% level when the comparison were made among varieties, and between crop seasons, and between areas. Interaction between types, crop seasons and locations had also been detected, indicating significantly environmental impacts on the yield and yield components. In addition to 1,000-grain-weight, the other three yield components did not correspond consistently to the variation of grain yield. Five varieties, namely Tainung 67, Tainan 5, Taitung 29, Taichung Sen 10 and Chianung Sen 11 yielded better than other varieties regardless of location and crop season. It was found that the varieties with high yield were quite stable. For the varieties of high yield in corp season, there were Tainung 62, Kaohsiung Sen 7 and Toyonishiki, Tainung Sen 12 for the first and second crop respectively. They all belonged to the panicle number type. And the positve correlations existed between crop seasons and between locations for the panicle number per hill, indicating stable responses to the environments