Effects Of Phosphate Fertilizer On The Growth Of Leaves And Fruits,and Yield Of Camellia Oleifera

Camellia oleifera Abel is an evergreen shrub or arbor Camellia genus.It is a native woody edible oil tree species in southern China.It have high ecological,economic and social benefits.Jiangxi province is the main producing area of C.oleifera plantations with749,000 hm².Phosphorus is the most important limiting factor for the growth of C oleifera in the acidic red soil of Jiangxi province.Therefore,in order to improve the theoretical basis of phosphorus nutrition about C oleifera,and provide scientific basis for intensive nutrient management of high efficiency and high yieid about C oleifera,this experiment carried out the effects of phosphorus fertilization on the growth of leaves and fruits,foliar phosphorus fractions and fruit yield of C.oleifera.The project was designed by a randomized block to conduct in situ control tests,and four treatments were set to investigate the response of the growth of leaves and fruits,foliar phosphorus fractions and yield and oil content about C.oleifera with the application rates of phosphate fertilizer,which added monometallic sodium orthophosphate（containing 58%of P₂O₅）single plant as 0g（P0）,34.55g（P1）,69.11g（P2）and 103.66g（P3）.The main results were as follows:（1）Phosphorus fertilization can promoted the growth of C.oleifera leaves.Phosphorus fertilization promoted the growth of leaf area,leaf length and leaf width of C.oleifera.Leaf area was the largest under P3 treatment than under other treatments.Total nitrogen and total phosphorus in leaves was increased and then tend to stable with phosphorus fertilization rates.Total potassium in leaves showed an"N"change with phosphorus fertilization rates.Organic carbon was decreased with phosphorus fertilization rates.N:P was the highest under P3 treatment.N:K was the highest under P2 treatment and K:P was the highest under P1 treatment.C:N and C:P was decreased with phosphorus fertilization rates.The nutrient reabsorption rate of total nitrogen,total phosphorus and total organic carbon reached the maximum in P2 treatment,and the total potassium reabsorption rate was the highest under P3 treatment.The correlation analysis shows that the increase of N:P promoted total nitrogen,total potassium and organic carbon reabsorption,the increasing of N:K and the decreasing of C:N promoted total nitrogen and total potassium reabsorption,C:P reduction contributed to the reabsorption of total phosphorus.（2）Phosphorus fertilization showed a positive effect on the content of structural phosphorus and metabolic phosphorus in C.oleifera leaves,but no significant effects of phosphorus fertilization were observed on the content of nucleic acid phosphorus,the residual phosphorus content decreased with phosphorus fertilization.The total phosphorus component accounts for more than 90%of total phosphorus.The proportion of structural phosphorus and nucleic acid phosphorus were not basically affected by the rate of phosphorusv fertilization.The proportion of metabolic phosphorus was higher in April and October under P2 and P3 treatments.The proportion of residual phosphorus was lower under phosphorus fertilization treatment than under none phosphorus fertilization treatment.There was a synergistic effect between different phosphorus components on phosphorus content in leaves,and there was an inhibition effect between different proportions.Phosphorus content decreased with the leaf area,increasd with leaf shape index and the total phosphorus content,and showed no significant correlation with N:P.（3）Phosphorus fertilization promoted fruit growth and development.Fruit height and diameter of C.oleifera was larger under P2 and P3 treatments than under P0 treatment.Fruit shape index decreased with phosphorus fertilization rates.Total nitrogen content,total phosphorus content and total potassium content was the highest under P3 treatment than under other treatments.（4）The fruit yield in single plant of C.oleifera was the highest under P2 treatment than under other treatments.Dry seed rate,dry seed kernel rate,seed kernel oil content,oil content in fresh fruit and oil production in single plant were all the highest in P3 treatment.The oil production in single plant grew slower with the increase of phosphorus fertilization.The fruit height and fruit diameter showed a significant positive correlation with the total phosphorus and total potassium content of fruit,the yield and oil content in single plant showed a significant positive correlation with total nitrogen and total potassium.There was a significant correlation between dry seed rate,dry seed kernel rate and total phosphorus and there was a positive correlation between fresh fruit oil content with total nitrogen,total phosphorus and total potassium.In conclusion,reasonable phosphorus fertilization in C.oleifera plantations can effectively promote the growth of C.oleifera leaves and fruits,the accumulation of metabolic phosphorus of leaves,and the yield of fruits.The indexes of leaves and fruits P2showed better under 69.11g or 103.66g phosphorus fertilizer per plant than other treatments in this study,and the oil production of single plant was the hightest under103.66g phosphorus fertilizer per plant than other treatments.Hence,in order to obtain high oil production,103.66g phosphorus fertilizer per plant was recommended for C.oleifera plantations with intensive management.And this study provided theoretical basis and technical support for improving the development of C.oleifera industry on P limited soil in south China.