Effects Of Fertilization And N,P,K Application Rates On The Growth,yield And Quality Of Pumpkin

Cucurbita Linn.is a large group,native to America,has a long history of cultivation,and is an annual trailing herb of Cucurbitaceae Cucurbita.The yield and quality of pumpkin are not only affected by the variety characteristics,but also by the external conditions such as soil and climate.Among them,fertilizer has the greatest impact.How to choose the appropriate fertilization method,improve the yield and quality of pumpkin,and reduce the amount of fertilizer application is of great significance.In order to provide scientific basis for the production of high yield and high quality of pumpkin,this study discussed how to achieve the best way of fertilization to improve the yield of pumpkin and the appropriate amount of nitrogen,phosphorus and potassium fertilization.The main results showed as follows:1.The effects of different fertilization methods on the growth,yield and quality of pumpkins were studied.The application of planting furrow fertilizer（T1）can increase the content of soluble sugar and soluble solids in pumpkin fruits;planting furrow fertilization（T2）was beneficial to increase the leaf area of pumpkin Index and duration of leaf area promote the accumulation of phosphorus in pumpkin fruits and increase the weight of single fruit;fertilization by planting border border furrow（T3）is beneficial to increase the number of fruits and yield per plant of pumpkin;planting of border crop furrow fertilization（T2）and Planting border border ditch fertilization（T3）can promote the growth rate of pumpkin fruit during the expansion period and increase the soluble protein content of pumpkin fruit.Under this test condition,it is recommended to use planting border furrow fertilization（T3）.2.Balanced fertilization of N,P and K（N,P,K ratio 1.5:1:1）can significantly increase the length of vine,stem diameter,growth amount and yield of pumpkin;balanced fertilization of N,P and K can increase the SPAD value,flavonoids,nitrogen balance index and anthocyanin content of pumpkin leaves.The values of F0,Fv/Fm,Fv/F0,q P,NPQ and Fm of pumpkin leaves increased first and then decreased with the increase of nitrogen application rate,and the nitrogen application rate was 170kg/ha².The effect of different P and K fertilizer application in 55～110kg/ha² could increase the fluorescence Fv/F0 value of pumpkin leaves,but had no significant effect on the fluorescence Fm,Fv/Fm,q P value of pumpkin leaves.Nitrogen fertilizer had a great influence on the fluorescence value of chlorophyll fluorescence curve of pumpkin leaves.The application of low and medium level nitrogen fertilizer（85～170kg/ha²）was beneficial to the increase of fluorescence value of chlorophyll fluorescence curve of pumpkin leaves.The fluorescence value of chlorophyll fluorescence curve of pumpkin leaves increased with the application of phosphorus fertilizer,but the difference of fluorescence value of chlorophyll fluorescence curve of pumpkin leaves was not significant.The absorption of light energy（ABS/RC）and heat dissipation energy（DIo/RC）in pumpkin leaves increased first and then decreased with the increase of nitrogen application rate.Different nitrogen application rates had no significant effect on the light energy（TRo/RC）and electron transfer energy（ETo/RC）captured in pumpkin leaves.Different phosphorus and potassium application rates had no significant effect on the activity parameters of reaction center in pumpkin leaves There was no significant effect of ABS/RC,DIo/RC and ETo/RC.3.According to the single factor analysis of pumpkin yield,the highest yield reached39638.69～41708.09 kg/ha² when the application rates of N,P and K fertilizer was 242.18kg/ha²,98.55kg/ha² and 84.03kg/ha²,respectively.According to the coupling effect of N,P and K fertilizer,the application retes of N,P and K fertilizer was 111.5kg/ha²,108.9kg/ha²and 72.13 kg/ha²,the best yield of pumpkin is 28336.6 kg/ha²～34422.8 kg/ha².According to the single factor analysis of pumpkin starch,soluble solids and soluble protein content,the highest content of pumpkin starch is 15.97-26.49 when the application amount of N,P and K is 165.75kg/ha²,141.625kg/ha² and 122.5kg/ha ²,respectively The highest content of soluble solids in pumpkin was 9.98%～11.7%when N,P and K were applied at 141kg/ha²,143.17kg/ha² and 139.67kg/ha²,respectively.The highest content of soluble protein in pumpkin was 16.09～18.33 mg·g^-1when N,P and K were applied at141kg/ha²,143.17kg/ha² and 139.67kg/ha²,respectively.