The Research On Growth Regulators And The Correlation Between The Growth And Soil Nutrition In The 10 Poplar Clones

Under the premise of the timber is relatively lack in our country,as an important tree species,the cultivation and breeding of poplar has been paid high attention by the state and industry.In this study,the seedling performance of 10 poplar clones was measured after singling,and the afforestation experiment of 10 clones was arranged in three different test regions(HongBei regionalization experimental forest(Wuhan,Hubei,China),Junshan regionalization experiment(Yueyang,Hunan,China)and Xidongting regionalization experimental forest(Changde,Hunan,China)).The diameters at breast height and growth heights of the 10 clones were determined in the first 3 years.The logistic growth models of 10 clones were fitted in the young period(three years)for diameters at breast height and growth heights.By measuring soil condition of 3 regions,the correlation between the poplar growth parameters and soil conditions was analyzed.The results showed that:(1)In the process of seedling growth,seedling heights and ground diameters of 10 poplar clones within six months after singling,seedling performance were significant different(P<0.05).The performance of clone 147 was the worst,it is not suitable for popularization and application in production;seedling performance were better of clone 476,623 and 680,and were better than the superior clone 77.(2)The 10 poplar clones afforested in three different regions,the growth differences between ten clones were significant(P<0.05),and the growth differences of the same clone grew in different regions also were significant.Diameters at breast height and tree heights of the clone 623,423 and 680 were relatively high,and were better than the superior clone 77;In addition,diameter at breast height and tree height of the clone 147 and 451 were relatively low.Such as,in Xidongting regionalization experimental forest,the height and diameter at breast height of the clone 623,423 and 680 respectively were over 16m and 22cm,but the height and diameter at breast height of the clone 147 and 451 respectively were below14.5m and 17cm.Therefore,in the selection of poplar young growth period,the clone 623,423 and 680 were better,and can to be further identified whether they are suitable for popularization and application in practical production through other ways.In the three regions,soil condition of Xidongting is more suitable for the growth of poplar clones.(3)The changes of diameter at breast height and tree height of 10 poplar clones were determined within three years after afforestation.Respectively,the logistic growth model of 10 clones were fitted,and the fitting degrees were higher than 0.900,model fitting effects were good.The models have important guiding significance for the production and management of ten clones in the future.(4)There were significant differences between the soil nutrient conditions of the three regions;and the growth of the same clones grow in different regions were very different.The correlation analysis results showed that the growth of 10 poplar clones were negatively related with rapidly available potassium(K),and the correlations between the clones growth and available nitrogen or available phosphorus were positively correlated.Some clones of tree height and diameter at breast height was significantly positive correlated with available N and available P.The results showed that nitrogen and phosphorus are main impact nutrient for the growth of young poplar,and the effect of potash fertilizer on young poplar growth is not obvious.