Study On The Effects Of N-P-K Ratio And Nutrient Solution Concentration On The Growth And Development Of Mini Cucumber (Cucumis Sativus L.)

Mini cucumber’s alias is stingless cucumber. Mini cucumber as the young fruit belongs to cucurbitaceae is a kind of high-grade fruit vegetables. As our demand for vegetables quality enhances unceasingly, the using of greenhouse soilless cultivation technology can get high quality and high yield cultivation of mini cucumbers, which can realize the annual supply and remarkable economic benefit. However the unreasonable using of fertilizer nutrients can waste nutrient and bring environment pollution, and it can weak the yield and quality of cucumber at the same time. Appropriate concentration and formula of nutrient solution are the key to soilless culture technology. Therefore, it is important with guiding significance to study the influence by different N-P-K ratio and different nutrient solution concentration on the growth and development of mini cucumbers by the ueing of soilless cultivation technology.This experiment studied the effect on the growth physiological indexes of mini cucumber in different concentration of N-P-K, studied the effect of the absorption of N-P-K elements in different ratio of N-P-K of mini cucumbers, established the corresponding mathematical model, and analysed the three factors of N-P-K on the index of the main effects and interaction effects, selected the optimal N-P-K with solution.The effects of different nutrient solution concentration in different period on the growth, yield and quality of mini cucumber were studied by the technology of soilless cultivation in this research. The research analyzed the effects on the indicators of the growth, physiology, yield and quality in different nutrient solution concentration in different period so as to provide theoretical basis for guiding production.The main results are as follows:1. Results of the research on the influence of N-P-K ratio on mini cucumber seedlings indicate:The Appropriate application of N-P-K fertilizer could promote the plant height, stem diameter, biomass, chlorophyll content and photosynthetic rate of mini cucumber seedlings. The influence of N-P-K three factors on the plant height, stem diameter, biomass, chlorophyll content and photosynthetic rate were significant. The contribution degree of the N-P-K three factors on the plant height, stem diameter and biomass was N>P>K. The contribution degree of three factors on the chlorophyll content and photosynthetic rate was N>K>P.The N-P-K content of the mini cucumber’s leaves were mainly affected by the applying of N-P-K fertilizer content. The influence of N-P-K three factors on nitrogen content of plant was in order of N>P>K. The influence of N-P-K three factors on phosphorus content of plant was in order of N>P>K. The influence of N-P-K three factors on the potassium content of plant was in order of K>N>P.Through a comprehensive selection of the optimum fertilizing formula on mini cucumber seedlings, the best solution is:Nitrogen concentration was 19.46-20.798 mmol/L. Phosphorus concentration was 1.23～1.1.30 mmol/L. Potassium concentration was 7.153～7.292 mmol/L.2. The influence of the growth, yield and quality of mini cucumbers under the nutrient solution concentration in different growth indicate:Increasing the nutrient solution concentration appropriately could promote the growth of plants, but high concentration of nutrient solution could inhibit the growth of plants. The prophase 1S, late 1.5S concentration of the processing could promote plant with height value of the maximum. Plant stem diameter value of treatment was the maximum in the processing of prophase 1.5S, late 1S concentration. Prophase 1.5S, late 1S concentration treatment was the most conducive to mini cucumbers’ leaf area growth. Total dry matter reached the maximum under the treatment of prophase 1.5S, late 1S.Plant growth prophase, root activity, chlorophyll content and photosynthetic rate were all positively correlated with the nutrient solution concentration. At later growth stage, chlorophyll content, root activity value were significantly higher than other processing under the BC, BB, CB (early IS, late 1.5S; early IS, late 1S; early 1.5S, late 1S) treatment. Photosynthetic rate value was significantly higher than other treatment under CB, BC, CC (early 1.5S, late 1S; early 1S, late 1.5S; early 1.5S, late 1.5S) treatment.The treatment that high concentration of nutrient solution in early period could increase production, but it was not conducive to raise the output of plants in high concentration processing through the whole growth period.Generally, BC processing (early 1S, late 1.5S) of the plant got the highest yield. It was significantly related between quality and the nutrient solution concentration of mini cucumber in fruiting period. With the increasing of the concentration of nutrient solution soluble protein content presents a downward trend after rising first. Nitrate content presented a tendency of rising with the increasing of concentration of nutrient solution. The concentration of nutrient solution of 1s stage in the treatment was beneficial to the improvement of the quality of mini cucumbers in the later. All in all, CB treatment (early 1.5S, late 1S) was the highest for quality.