The Comparison Research On Growth, Physio-Ecology Characteristics Of Different Varieties Of Pecan

This paper discussed23varieties of pecan directly introduced from the U.S.A.Through studied on the growth, the beginning year yield of nut, nut characters, photosynthetic physiological indexes. The author also compared the soil structure and nutrient indexes of different plots, which used for plant pecan for10years. The results showed as following:1. The survival rate was significantly different from different sites and varieties. The survival rate was high in Hefei and Hanshan site, but was low in Zongyang site. The highest survival of pecan varieties were Cater csv18-24、Moore, at73%above. Hnghes csv6-1-、Harris svper csv18-0had lower preservation, were only26%. Moore, Cater csv18-24had higher survival in Hefei site.Sdling csv10-5, Forkert csv5-5had higher preservation in Hanshan site; Sdling csv16-11, Sdling csv10-5had higher survival in Qianshan site; Moore, Sdling csv3-6had higher preservation in Zongyang site.2. The growths were significantly different from different varieties. Overall, the pecan had most adaptability in Hanshan site, Hefei and Zongyang sites to the second, Qianshan site to the worst. Among different varieties, Sdling csv16-11,Magenta csv17-14had most adaptability in Hefei site. Elliott,Wankeenah had most adaptability in Hanshan site; Sdling csv15-10had most adaptability in Zongyang site; Sdling csv13-14had most adaptability in Qianshan site.3. The nut characters and the beginning year yields of nut were also different from different varieties. Overall, the yield of nut was large in Hefei; Zongyang sites to the second; Qianshan site to the worst. Among different varieties, Elliott, James had large yields of nut in Hefei site; Moore, Moneymaker had large yields of nut in Hanshna site; Magenta csv17-14, Moore had large yields of nut in Zongyang site.4. All Nitrogen and total Phosphorus content of each site was increased with the reducing of the soil depth, but the content of Kalium had positive correction with the soil depth. The soil nutrient had influence with the growth and the beginning year yield of nut, all Phosphorus had significantly positive correlation with tree height and the weight of single nut. And all Kalium and the beginning of fruit production was significantly positive correlation.5. The net photosynthetic rate and watershed utilization of James and Elliott were significantly changed, but the volum and the peak time were differences.The net photosynthetic rate of the two varietes had negative correlation with photosynthetic active radiation, intercellular CO2concentration and air temperature, but were significantly positively correlated with the stomatal conductance. James’s light compensation point was lower than Elliott, but the maximum net photosynthetic rate and the quantum efficiency was higher than Elliott.It indicated that the James variety had stronger shade tolerance and drought resistence, larger range of light adaptation.6. The graft methods, the collection period of scion and the different treatment of scion all effected graft survival rate. The most ideal combination was the Al×Bl×C2, which the mean survival rate reached25%. So the best combination was using cut method, using by the scion with the on-demand access and use of exogenous hormones.