Selection Of Nitrogen And Potassium Interactions And Effect Of Disease Resistance On Cultivation Of Cucumber In Greenhouse

This experiment studied the effects of the different NK ratio on growth, yield andquality，photosynthetic physiological with cucumber for material，Matrix nutrientand related enzymes activities of cucumber in the greenhouse were determined inorder to provide theoretical basis for rational fertilization cucumber. The main resultsare as follows:1. The appropriate add potassium fertilizer can improve the plant growth, promotethe fresh weight and dry weight of roots, stems, leaves in greenhouse cucumber. Thegrowth of treatment T3(N:K=1:1.8) is in good condition.2. Adding potassium fertilizer can promote the photosynthetic index, and promotethe cucumber’s photosynthesis. The highest content of chlorophyll is the treatment ofT3(N:K=1:1.8). The photosynthetic rate, stomatal conductance, intercellular CO2concentrations, and transpiration rate are different with the increased amount ofpotassium fertilizer. Taken together, The strongest photosynthesis is treatment T3(N:K=1:1.8).3. Different NK ratios are relatively obvious different between the early and thelater yield of cucumber, but no significant impact on the middle yield. T4(N:K=1:2.0)behaves the highest yield in organic soil cultivation, the highest yield is the T3(N:K=1:1.8) in ordinary soil cultivation. Ordinary soil cultivation of cucumberproduction is lower than organic soil cultivation. In a certain range of increasedappropriate potassium fertilizer can improve the solid content, total sugar content,Vitamin C content and crude protein content, while reduced the nitrate content. Thebest treatment of the fruit quality of cucumber is T3(N:K=1:1.8).4. The highest activity of nitrate reductase and glutamine enzyme are T3 (N:K=1:1.8), the activity of T4is reduced. The test shows that, the appropriatepotassium fertilizer could improve the nitrate reductase and glutamine enzyme activity,which reduce the nitrate content of cucumber fruits, improve fruit quality.5. Increasing potassium fertilizer appropriately can effectively reduce the soilbulk density, and increase the soil total porosity. The total porosity of T3(N:K=1:1.8)in organic soil cultivation reached for66.35%,than ordinary soil cultivation matrixincreased15.27%~21.62%.The fungi, bacteria, and actinomyces, such as the numberof microorganisms in cultivation matrix, also increased with the potassium fertilizerincreased. The microorganism’s quantity of organic soil is higher than the ordinary soilcultivation.6. Cucumber downy mildew and powdery mildew incidence to deal with T3(N:K=1:1.8) minimum, the application of potassium fertilizer on cucumber fusariumwilt and die strain phenomenon has no effect. The application of potassium fertilizercan enhance the cucumber plant growth, promote the growth and development ofcucumber, resulting in enhanced plant resistance.Summarizing the analysis results, the best substrates NK ratio levels for the highyield, good quality under the study condition were N:K=1:1.8. Organic soil cultivationis better than ordinary soil cultivation on indicators of cucumber growth anddevelopment and fruit quality.