環境條件對水稻收穫指數之影響

Influence of Environmental Conditions on Harvest Index of Rice

林富雄(Fu-Hsiung Lin)

《花蓮區農業改良場研究彙報》 4期 (1988/04) Pp. 1-2

摘要

水稻收穫指數對環境因素很敏感。本試驗利用不同種植月份，氮肥及密度進行探討，其結果顯示二品種經周年種植，其收穫指數受種植月份之影響。一月份及二月份種植區產量及收穫指數均最高，而七月份種植時其收穫指數亦較夏季其他月份要高。增施氮肥使谷產量及總乾物量均增加，但使第一期作之收穫指數減低，此因谷產量因增施氮肥而增加之速率比總乾物量增加速率較低。此種關係在第二期作則不明顯，因為第二期作之收穫指數受氮肥用量影響小。一般而言，收穫指數、谷產量及總乾物量均隨族群密度增加而增加，但收穫指數對密度之反應較谷產量及總乾物量小。

並列摘要

Monthly plantiings of two rice cultivars throughout the year (1975) showed that harvest index was affected by planting date. January and February plantings gave highest grain yield and highest harvest index, and July planting also gave higher harvest index than plantings in other summer months. The application of nitrogenous fertilizers brought about increases in grain yield and total dry weight, but a decrease in harvest index in the first crop season. This was because the rate of grain yield increase in response to nitrogen was lower than that of total dry weight. These relations were not observed clearly in the second crop season as harvest index did not change much in response to nitrogen application. In general, harvest index, grain yield and total dry weight increased with an increase in population density, but harvest index showed smaller differences due to planting density than those in grain yield and total dry weight.