关键词: 土壤熏蒸, 生物有机肥, 连作土壤, 尖孢镰刀菌, 枯萎病防控

Abstract: In this study, the adaptability of Phytolacca americana to light environment was analyzed based on the investigation of the photosynthetic performance indices, specific leaf area, calorific value, carbon and nitrogen use efficiency in P. americana under both shaded and unshaded environments. The results showed that the light saturation point, light compensation point and respiration rate all decreased significantly in the shaded P. americana, but the apparent quantum yield, maximum net photosynthetic rate and photosynthetic performance index showed no significant difference between the shaded and unshaded plants. In addition, the specific leaf area of the shaded P. americana was much larger, while the chlorophyll a/b ratio, the calorific value, carbon use efficiency and water use efficiency were significantly lower than those of the unshaded plants. Furthermore, the photosynthetic nitrogen use efficiency, mineral element use efficiency and light use efficiency in the shaded plants were significantly higher than those in the unshaded plants. The results suggest that P. americana can adjust its adaptability morphologically and physiologically to varied light environments, so as to make an efficient use of available radiation.

Key words: soil fumigation, Fusarium wilt disease control., continuous cropped soil, Fusarium oxysproum, biofertilizer