| NO.1Jinyou cucumber was selected as experimental material. The treatments includewater and fertilizer two factors, three levels each. Three water levels were:3600m3/hm2(W1),2850m3/hm2(W2),2100m3/hm2(W3), and three fertilizer levels were: N675+P2O5270+K2O702kg/hm2(F1), N525+P2O5210+K2O546kg/hm2(F2), N375+P2O5150+K2O390kg/hm2(F3). The six levels combined at random, nine combinations in total, and thetraditional irrigation and fertilizer amount was set as control, to study their influence ongrowing development, yield and qualities of cucumber under different water and fertilizercombinations. The results showed that:1. Effects of different water and fertilizer combinations on growth indexes of cucumber:At seedling stage, when it was set at the same water level, lower fertilizer condition couldmeet the growth requirements of cucumber for height and leaf number increasing, andmedium fertilizer condition was beneficial to stem diameter. At early and middle fruitingstages, water had significant influence on plant morphological indexes. The effects of wateron plant height and leaves ordered W1>W2>W3under F1level, result of W2treatment wasthe best under F2and F3levels. The effects of water and fertilizer interactions on height, stemdiameter and leaf number of cucumber was not significant. Leaf growing rate was highest atearly fruiting stage. Higher water and fertilizer levels were to the benefit of leaves.2. Effects of different water and fertilizer combinations on physiological indexes: At thesame fertilizer levels, the highest net photosynthetic rate and transpiration rate of cucumberleaves was W1treatment. However, the effects on stomatal conductance had different results,which showed that both indexes of W1and W3treatments were lowest at early fruiting stageand middle fruiting stage respectively; at end fruiting stage, the demand for water of thesethree physiological processes declined. At different fruiting stages, water and fertilizerinteractions had significant or very significant effects on net photosynthetic rate andtranspiration rate of leaves. At middle fruiting stage, the water use efficiency of cucumberleaves was lowest, and when it was set at the same fertilizer or water level, water useefficiency of W2or F2was highest. 3. Effects of different water and fertilizer combinations on yield of cucumber: Water andfertilizer interactions and water had significant effects on yield of cucumber. Under W1andW2levels, the yield increased if more fertilizer were used. But the trend was opposite underW3level. The yields of W1F1and W1F2were significantly higher than other treatments.Except for leaves at early fruiting stage and stem diameter at middle fruiting stage havingpositive correlations with yield, at other growth stages, the plant height, stem diameter, leafnumber and leaf growing rate all had negative correlations with yield. Net photosynthetic rateand transpiration rate of leaves both had significant or very significant positive correlationswith yield of cucumber. The correlation between stomatal conductance and yield was positive,but not significant.4. Effects of different water and fertilizer combinations on qualities of cucumber: Effectsof water and fertilizer interactions on nitrate content of cucumber fruits was not significant ateach stage. Under the same water level, nitrate content increased with the increase of fertilizeramount. When water level was higher, the nitrate content was lower. Soluble protein of fruitsof W1F1treatment was higher at early fruiting stage, but at middle and end fruiting stage, itturned out to be W2F2treatment. Under the same fertilizer level, lower watering amount wasin favor of soluble sugar and Vc content going up; when fertilizing amount was higher, it wasbeneficial to accumulating soluble sugar in cucumber fruit. Water use efficiency had positivecorrelation with qualities of cucumber at each stage. The correlation of yield of cucumberwith soluble sugar content, Vc content and nitrate content at middle fruiting stage were allnegative. |
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