Studies On Key Technology For Cultivated Standardization Of Rheum Palmatum L

Rheum palmatum was selected as material, the key technologies of standardizedcultivation including seedling, fertilization, transplanting density, and harvesting time Lixian,Gansu Province. The main results are as follows:1. The study of sowing quatity showed that the comprehensive indicator of R.palmatum seedlings under sowed at65kg/hm²of seeding quantity was outstanding ingrowth and development resulting in medium size and good quality of seedlings and highsurvival rate of transplant, indicating65kg/hm²was the best density in seedling cultivationfor the seedlings in Lixian considered both the benefits and seedlings quality.2. The study of sowing time showed the comprehensive index of R. palmatumseedlings was excellent when sowed from April9thto April19th, resulting good seedlingswith strong root activity, good quality, high yield and high survival rate of transplant,indicating the best time for R. palmatum to be sowed in Lixian, ensured the quality ofseedlings and economic benefits.3. The results of fertilized experiment showed that the nitrogen and potash fertilizerapparently promoted R. palmatum plant growth, especially the height of plant, the leafnumbers, the weight of fresh root compared with the control without fertilization. The120kg/hm²of N,60g/hm²of P₂O₅and30g/hm²of K₂O were the adapted fertilization quantityfor R. palmatum resulting in good comprehensive index. The amount of fertilized N was thekey factor to influence the production of R. palmatum, suggesting that the soil shouldpriority to be frtilizated mainly with nitrogen under combined reasonable fertilization withP₂O₅and K₂O. The fitted equation of yields with fertilizated quantity indicated that theoptimum amount of N, P22O5and K₂O was132.947kg/hm²,25.548kg/hm²,30.435kg/hmrespectively resulting12981.29kg/hm²of yield.4. The study of planting density showed the yield of R. palmatum could be improvedunder reasonable planting density. With the density further increased, the plant showeddecrease in plant height, root length, the lateral roots, the size of leaves even the weight ofper root. The seedlings were excellent under the70cm and75cm of row and plant spaceshowing healthy growth and developed roots resulting in outstanding production andeconomic benefits, suggesting the debsity at the level of19048plants per hectare with70cm and75cm of row and plant space was suitable for the production of R. palmatum inLixian, ensured the best production and economic benefits.5. The study of year and harvest time showed that the appropriate growth years andharvest time could improve the yield and quality of R. palmatum. The triennial plants werethe best in production with the harvest duration from October10thto November10thandbest time around November10th. The harvest time should vary with the area flexiblelydepending on its specific situation.