琉球列島のサトウキビ畑における雑草の生理・生態 : 第2報タチスズメノヒエの生育と種子生産に及ぼす窒素施肥量の影響

概要

論文の詳細を見る
Effects of five nitrogen levels (0, 5.0, 10. 5, 21.0kg per 10 acres) on the growth and seed production of Paspalum urvillei Steud., an agressive sugarcane field weed, were investigated. 1. Plant height increased rapidly at all nitrogen levels throughout the vegetative growth period with a subsequent decrease at 0 level. Plant height at the end of the experiment was the lowest at 0 level in remarkable contrast with values at other levels. 2. Tiller number, leaf area and top dry matter weight increased appreciably with increasing nitrogen level. No substantial variations were observed in maximum root length and root dry matter weight. 3. Differences in nitrogen level had almost no effect on days to heading. 4. Panicle number and panicle weight increased with increasing nitrogen level. Percentage of productive tillers decreased rapidly with the increase of the nitrogen level. 5. In the characters associated with vegetative growth, the coefficient of variation was large for the tiller number and top dry matter weight, especially for the former character. In the characters associated with reproductive growth, the variation was high for the panicle number per plant and panicle weight per plant. The variation in 1,000 seed weight and days to heading was extremely low. 6. In this weed, heavy application of nitrogen in a field may result in the excessive growth of the top part and subsequently it may cause shading on crop.
日本雑草学会の論文
1985-08-26