| Phosphorus fertilizer is an important factor to the yield and quality of kiwifruit trees.Biomass,phosphorus concentration and accumulation were studied in the cortex and xylem in different parts of field-grown Actinidia Deliciosa cv.Qinmei kiwifruit trees in 2005 and 2006 growing seasons in Guanzhong of Shaanxi Province,China.The objective of this study was to find the dynamic variety of phosphorus uptake,transportation and distribution in different parts of kiwifruit trees.The results showed that the biomass of plant vegetated slowly from coppice shoot sprout period to fruit setting period,and developed quickly from fruit setting period to fruit maturity,and dropped rapidly after fruit harvested and defoliation,and the biomass of roots vegetated slowly in the whole year.Phosphorus content order in the organs were roots,leaves and fruits > stems;cortex > xylem.From coppice shoot sprout period to fruit setting period 78.89% of phosphorus needed by leaves came from soil,4.44% came from root transportation,and 16.67% came from stem transportation.The phosphorus absorption capacity of plant is much more than other periods from fruit setting period to the last days of fruit expansion stage,occupying 55.39% of the total uptake,so this period was the maximum efficiency period of phosphorus absorption.Totally 36.95 kg/hm2 phosphorus was absorbed in a year(the harvest was 40.16 t/hm2),10.92 kg/hm2 phosphorus was absorbed from harvest season to fruit setting period and 26.03 kg/hm2 phosphorus was absorbed in fruit growing period,accounting for 29.55% and 70.45% of total uptake respectively. |