Effects Of Phosphorus Nutrition On Growth And Photosynthetic Characteristics Of Jerusalem Artichoke At Different Growth Stages

Jerusalem artichoke(Helianthus tuberosus L.)belongs to family Compositae,and the genus of sunflower,which originated in North America and was introduced into China by Europe.Because of the characteristics of Jerusalem artichoke,it can be widely used in ecological rehabilitation,food processing,animal feed,biomass energy and so on.Jerusalem artichoke has good growth characteristics,that make it can grows in marginal land where the food crops can't grow up.Scale planting of Jerusalem artichoke in marginal land,can not only meet the needs of industrialization of Jerusalem artichoke,also can have the effect of improving ecological environment,Implement its economic benefit,social benefit and ecological benefit,avoiding the problem of land dispute with grain in the process of developing Jerusalem artichoke industry,and safeguard the country's food security.Phosphorus is one of the essential elements for plant growth,and is involved in various life activities in plants.Abundant phosphorus supply plays an important role in the growth and development of plants.Based on the excellent cultivar of lan zhou university which is suitable for cultivation in the northwest semi-arid region 'lan yu1 'as the research object,explore the effect of p nutrition on Jerusalem artichoke photosynthetic growth characteristics,the optimal p levels of Jerusalem artichoke,for Jerusalem artichoke marginal land in the northwest arid areas of high-yield cultivation and utilization to provide theoretical basis for phosphorus removal.Experimental results show that:(1)Phosphorus nutrition had a significant effect on the plant height,Stem diameter and leaf area of Jerusalem artichoke in different growth period.Phosphorus nutrition promoted plant height,stem diameter and leaf area of Jerusalem artichoke at different growth stages.Under the P3 treatment,the plant height of Jerusalem artichoke respectively increased by 69.98 %,44.99 %,15.07 % and 10.98 %;The Stem diameter increased by 54.91%,34.76%,27.31% and 43.40%;leaf area increased by 181.57%,112.10%,11.87% and 43.78%.The increasing phosphorus had no significant effect on the number of leaves of Jerusalem artichoke during seedling stage.In the other growth stages,the number of leaves of the artichoke leaves showed an increasing trend,but the effect was much lower than that of leaf area.(2)The effect of phosphorus nutrition on the photosynthetic characteristics of Jerusalem artisan at different growth stages.P can promote the net photosynthetic rate of Jerusalem artichoke at different growth stages,especially at seedling stage,compared with CK,the net photosynthetic rate(Pn)of Jerusalem artichoke increased by 67.74 %,97.29 % and 89.83 %.The Pn of Jerusalem artichoke increased significantly at different growth stages under P2,and increased by 97.29 %,40.31 %,23.09 % and 31.55 % respectively compared with CK.P has an effect on stomatal conductance of Jerusalem artichoke at different growth stages,the stomatal conductance of Jerusalem artichoke decreased first and then increased during seedling stage and florescence stage.During rhizomes formation stage and mature stage the stomatal conductance of Jerusalem artichoke increased between different treatments.The transpiration rate of Jerusalem artichoke had no significant difference between different treatments in the seedling stage.The transpiration rate of Jerusalem artichoke increased first and then decreased with the increase of phosphorus nutrition level during other growth periods.The transpiration rate of Jerusalem artichoke was the highest under P3.Phosphorus had different effects on the water use efficiency of Jerusalem artichoke at different growth stages.The water use efficiency of Jerusalem artichoke increased first and then decreased at flowering stage.In the other growth stages water use efficiency of Jerusalem artichoke increased with the increase of phosphorus nutrition.(3)Phosphorus nutrition significantly promoted the biomass of different organs of Jerusalem artichoke at different growth stages.The leaf biomass of Jerusalem artichoke increased by 95.67 %,123.13 %,131.48 % and 180.88 % at different growth stages under P3.The biomass of stem increased by 260.4 %,209.84%,137.10% and 226.13 % respectively.The biomass of roots increased by 98.89%,213.63%,77.46% and 152.65% respectively.There was no significant difference in tuber biomass between different treatments at flowering stage.The biomass of Jerusalem artichoke tuber increased by 46.90 %,82.86 % and 97.42 % respectively under different phosphorus nutrition levels at maturity stage.(4)Phosphorus nutrition affected biomass allocation of Jerusalem artichoke organs at different growth stages.Phosphorus promoted the biomass increase of Jerusalem artichoke organs and promoted the biomass distribution to the ground.With the increase of phosphorus nutrition level,the root weight ratio of Jerusalem artichoke decreased significantly in seedling stage,and decreased in other growth stages.The tuber proportion decreased from flowering stage.