Two field trials were clone to evaluate the effects of plant density on the growth, development and yield of safflower. The results showed that plant density and season of growth had significant (P ≤ 0.01) effects ...Two field trials were clone to evaluate the effects of plant density on the growth, development and yield of safflower. The results showed that plant density and season of growth had significant (P ≤ 0.01) effects on growth, development, yield components, yield and oil content of safflower. Increasing safflower plant density from 100,000 to 250,000 plants ha^- significantly reduced plant height (13.2%-21.3%), branch number plant^-1 (37%-54.7%), leaf number plant^-1 (39%-39.2%), leaf area (19.5%-53%), plant spread (39.6%-54.4%), root length (28.1%-54.4%), plant biomass (17%-50%), capitula size (12%-12.7%), capitula number plant^-1 (39.5%-50.5%), seed number capitula~ (39%-45%), capitula weight (3.3%-3.6%), seed yield (67.9%-69.8%) and seed oil content (14.7%-20.8%). The reduction in vegetative growth, yield components, yield and oil content of safflower due to increased plant density was attributed to inter and intra-plant competition for light, nutrients and water necessary for growth and development. The differences between winter and summer grown safflower were attributed to difference in day and night temperature (DIF) and the average daily temperature which were optimum for safflower growth in winter. It was concluded that under Botswana conditions or in semi-arid areas, safflower should be planted at 50 cm × 20 cm or wider in order to maximize yield and oil content and allow the plants to express their maximum genetic potential.展开更多
文摘Two field trials were clone to evaluate the effects of plant density on the growth, development and yield of safflower. The results showed that plant density and season of growth had significant (P ≤ 0.01) effects on growth, development, yield components, yield and oil content of safflower. Increasing safflower plant density from 100,000 to 250,000 plants ha^- significantly reduced plant height (13.2%-21.3%), branch number plant^-1 (37%-54.7%), leaf number plant^-1 (39%-39.2%), leaf area (19.5%-53%), plant spread (39.6%-54.4%), root length (28.1%-54.4%), plant biomass (17%-50%), capitula size (12%-12.7%), capitula number plant^-1 (39.5%-50.5%), seed number capitula~ (39%-45%), capitula weight (3.3%-3.6%), seed yield (67.9%-69.8%) and seed oil content (14.7%-20.8%). The reduction in vegetative growth, yield components, yield and oil content of safflower due to increased plant density was attributed to inter and intra-plant competition for light, nutrients and water necessary for growth and development. The differences between winter and summer grown safflower were attributed to difference in day and night temperature (DIF) and the average daily temperature which were optimum for safflower growth in winter. It was concluded that under Botswana conditions or in semi-arid areas, safflower should be planted at 50 cm × 20 cm or wider in order to maximize yield and oil content and allow the plants to express their maximum genetic potential.