Study On The Irrigation Mode Of Cucumber Under The Condition Of Culture Coconut Bag In Solar Greenhouse

In order to explore the suitable irrigation mode of cucumber under the condition of cocobag cultivation in solar greenhouses,this experiment was conducted in March 2017 to January 2018 at the laboratory of Sunlight Greenhouse and Horticultural Science and Engineering College of Horticultural Experiment Station of Shandong Agricultural University.As the cultivation substrate,cucumber variety“Jinyou No.35”was selected as the test material,and five different irrigation frequencies were set for 1 time/day?R1?,2 times/day?R2?,4 times/day?R3?,6 times/day?R4?and 8 times/day?R5?respectively.0.6 L/strain/day?r1?,0.8 L/strain/day?r2?,1.0 L/strain/day?r3?,1.2 L/strain/day?r4?,1.4 L/strain/day?r5?for five different irrigation amounts,two trials were used to study the effects of different irrigation patterns on physiological characteristics,water use efficiency,yield,and quality of cucumber in solar greenhouses.The optimum irrigation pattern of cucumber under the condition of cocoon bag cultivation in solar greenhouse is to provide a theoretical basis for future research on precision irrigation of cucumber,and to provide theoretical basis and technical guidance for cucumber bag cultivation in solar greenhouse.The main findings are as follows:1.Effects of different irrigation frequency on physiological characteristics of cucumber under the condition of culture coconut bag in solar greenhouse.1.1 The irrigation frequency was increased on the basis of irrigate 1 time per day,and the plant height,stem diameter,leaf area and root activity of cucumber plants were significantly increased,and the aboveground growth of cucumber was significantly promoted,but the influence on the number of leaves of cucumber plants was no significant.The average diameter and total volume of cucumber roots were increased,total root length and root tip number were decreased,dry weight of roots was reduced,and root-shoot ratio was decreased.1.2 The irrigation frequency was increased on the basis of irrigate 1 time per day,which significantly increased the chlorophyll content and carotenoid content of cucumber leaves,increased the net photosynthetic rate of leaves,reduced the intercellular CO₂ concentration of leaves,and increased the stomatal conductance of cucumber leaves,and transpiration rate increase the water evaporation of the plant leaves.1.3 The irrigation frequency was increased on the basis of irrigate 1 time per day,and the single cucumber weight,the yield per plant,the number of individual cucumbers and the water use efficiency were significantly increased.1.4 When the irrigation frequency was increased to 6 times per day,the cucumber plant height,stem diameter,leaf area,root activity,photosynthetic characteristics,yield,and water use efficiency no longer increased;when the irrigation frequency was increased to 8 times per day,the plant height,stem diameter,leaf area,root vigor,photosynthetic characteristics,yield,and water use efficiency of the cucumber decreased,but there was no significant difference between treatments with 4 and 6 irrigations per day.In summary,the yield and water use efficiency of the plants treated with 4 times/day?R3?were higher than those of other treatments and could be used as an irrigation mode under cocoon bag culture conditions.2.Effects of different irrigation levels on physiological characteristics of cucumber under the condition of culture coconut bag in solar greenhouse.2.1 With the increase of irrigation amount,the plant height and stem diameter of cucumber plants increased at first and then remained unchanged.The leaf area,root activity,root-shoot ratio increased first,then decreased,total root length increased,and root tip number decreased.2.2 With the increase of irrigation amount,the chlorophyll content,carotenoid content and net photosynthetic rate of cucumber leaves increased first and then decreased,and the transpiration rate increased.2.3 Different irrigation amounts did not have a significant effect on the temperature of the substrate between treatments,but significantly affected the relative water content of the substrate.The more irrigation,the higher the relative water content of the substrate.Among them,the treatment of 1.4 L/strain/day was performed reached saturation relative water content at per irrigation;2.4 With the increase of irrigation,the yield of cucumber increased first and then decreased,but the water use efficiency showed a decreasing trend.2.5 Increasing the amount of irrigation on the basis of 0.6 L/strain/day treatment can increase the content of cucumber soluble protein,and reduce the content of nitrate and soluble sugar.In summary,the yield of plants treated with 1.0 L/strain/day?r3?was high,the water use efficiency was moderate,and the quality was good.It can be used as an irrigation mode under cocoon bag cultivation conditions.