The effects of leaf water status in a wheat canopy on the accuracy of estimating leaf area index (LAI) and N were determined in this study using extracted spectral characteristics in the 2 000-2 300 nm region of the s...The effects of leaf water status in a wheat canopy on the accuracy of estimating leaf area index (LAI) and N were determined in this study using extracted spectral characteristics in the 2 000-2 300 nm region of the short wave infrared (SWI) band. A newly defined spectral index, relative adsorptive index in the 2000-2300 nm region (RAI2000-2300), which can be calculated by RAI2000-2300 = (R2224 - R2054) (R2224 + R2054)-1 with R being the reflectance at 2224 or 2054 nm, was utilized. This spectral index, RAI2000-2300, was significantly correlated (P < 0.01) with green LAI and leaf N concentration and proved to be potentially valuable for monitoring plant green LAI and leaf N at the field canopy scale. Moreover, plant LAI could be monitored more easily and more successfully than plant leaf N. The study also showed that leaf water had a strong masking effect on the 2 000-2 300 nm spectral characteristics and both the coefficient between RAI2000-2300 and green LAI and that between RAI2000-2300 and leaf N content decreased as leaf water content increased.展开更多
Sweet basil （Ocimum basilicum L.） is a popular culinary herbal crop grown for the fresh or dry leaf, essential oil and seed markets. Recently, basil has been shown to rank highest among spices and herbal crops for x...Sweet basil （Ocimum basilicum L.） is a popular culinary herbal crop grown for the fresh or dry leaf, essential oil and seed markets. Recently, basil has been shown to rank highest among spices and herbal crops for xanthophyll carotenoids, which are associated with a decreased risk of cancer and age-related eye diseases. Nitrogen fertilizer encourages vegetative growth and increases oil yield in aromatic plants by enhancing leaf area development and photosynthetic rate. Our goal was to determine the influence of different concentrations of nitrogen （N） fertilization on basil physiology. The trial examined the cultivation of Ocimum basilicum L. （variety Genovese gigante）. The experiment was carried out under Mediterranean climatic conditions. The experiment considered the adoption of three nitrogen （N） treatments （0, 160, 240 kg N ha-1）. The following biometric parameters were determined： plant height, leaves per plant, leaf to stem ratio, number of branchings per plant, leaf area index （LAI）, above-ground fresh and leaf biomass. Considering the parameters most strictly linked to the economic results （total fresh weight, fresh weight of the leaves and total dry weight）, we found that 160 kg N ha^-1 treatment showed the best performance.展开更多
基金Project supported by the National High Technology Research and Development Program of China (863 Program)(No. 2002AA243011)the National Key Basic Research Support Foundation of China (No. G2000077907)
文摘The effects of leaf water status in a wheat canopy on the accuracy of estimating leaf area index (LAI) and N were determined in this study using extracted spectral characteristics in the 2 000-2 300 nm region of the short wave infrared (SWI) band. A newly defined spectral index, relative adsorptive index in the 2000-2300 nm region (RAI2000-2300), which can be calculated by RAI2000-2300 = (R2224 - R2054) (R2224 + R2054)-1 with R being the reflectance at 2224 or 2054 nm, was utilized. This spectral index, RAI2000-2300, was significantly correlated (P < 0.01) with green LAI and leaf N concentration and proved to be potentially valuable for monitoring plant green LAI and leaf N at the field canopy scale. Moreover, plant LAI could be monitored more easily and more successfully than plant leaf N. The study also showed that leaf water had a strong masking effect on the 2 000-2 300 nm spectral characteristics and both the coefficient between RAI2000-2300 and green LAI and that between RAI2000-2300 and leaf N content decreased as leaf water content increased.
文摘Sweet basil （Ocimum basilicum L.） is a popular culinary herbal crop grown for the fresh or dry leaf, essential oil and seed markets. Recently, basil has been shown to rank highest among spices and herbal crops for xanthophyll carotenoids, which are associated with a decreased risk of cancer and age-related eye diseases. Nitrogen fertilizer encourages vegetative growth and increases oil yield in aromatic plants by enhancing leaf area development and photosynthetic rate. Our goal was to determine the influence of different concentrations of nitrogen （N） fertilization on basil physiology. The trial examined the cultivation of Ocimum basilicum L. （variety Genovese gigante）. The experiment was carried out under Mediterranean climatic conditions. The experiment considered the adoption of three nitrogen （N） treatments （0, 160, 240 kg N ha-1）. The following biometric parameters were determined： plant height, leaves per plant, leaf to stem ratio, number of branchings per plant, leaf area index （LAI）, above-ground fresh and leaf biomass. Considering the parameters most strictly linked to the economic results （total fresh weight, fresh weight of the leaves and total dry weight）, we found that 160 kg N ha^-1 treatment showed the best performance.
