| Watermelon（Citrullus lanatus（thunb.）Matsum&Nakai.）is an important horticultural crop in China and even in the world.In the middle and late stages of watermelon growth,the root system slows down,its function gradually declines,and the plant’s ability to absorb nutrients also tends to weaken.Application with foliar fertilizer can compensate for insufficient soil fertilization,prevent premature plant senescence,and promote nutrient balance in watermelon.However,the current market has a wide variety of foliar fertilizers with varying quality,and farmers lack scientific and effective technical guidance when selecting and applying them.Excessive or blind fertilization is a common phenomenon.This study studied the effects of selenium fertilizer,trehalose,phosphorus and potassium fertilizer and their combination on the growth,yield and fruit quality of watermelon cultivar’Nongkeda No.5’,providing theoretical guidance for scientific application of foliar fertilizer in watermelon production.The main results are as follows:1.The effect of foliar spraying with different concentrations of selenium fertilizer(0,0.005,0.015,0.030,0.050 g·L-1)on watermelon yield and fruit quality.The appropriate concentration of selenium fertilizer treatment can significantly improve the quality and yield of watermelon fruit.Among them,0.050 g·L-1selenium fertilizer treatment had the best effect on improving fruit quality.Compared with the control,the content of soluble solid,total soluble sugar,and soluble protein in the center of the fruit increased by 7.61%,29.90%,and 32.00%,respectively.0.005,0.015,0.030,and 0.050 g·L-1selenium fertilizer treatments all significantly increased watermelon yield,and there was no significant difference among the four treatments.Therefore,considering the fruit quality and yield comprehensively,the optimal application concentration of selenium fertilizer is 0.050 g·L-1.2.The effect of foliar spraying with different concentrations of trehalose(0,2,4,6,8 g·L-1)on watermelon yield and fruit quality.The appropriate concentration of trehalose treatment can significantly improve the quality and yield of watermelon fruit.Among them,6 g·L-1trehalose treatment had the best effect.Compared with the control,the content of central soluble solids,marginal soluble solids,soluble protein and lycopene in fruits treated with 6 g·L-1trehalose increased by 11.24%,18.64%,30.43%and 12.69%respectively.In terms of yield,the treatment with 6 g·L-1trehalose increased yield by 19.32%compared to the control.Therefore,considering both fruit quality and yield,the effect of 6 g·L-1trehalose is better than that of 0.050g·L-1selenium fertilizer3.Based on the good effects of trehalose,further research was conducted on the effects of trehalose(6.0 g·L-1),mineral potassium fulvic acid(0.5 g·L-1),potassium dihydrogen phosphate(1.0 g·L-1),potassium phosphite(1.5 g·L-1)and their combination treatments on the quality and yield of watermelon fruit.Based on the comprehensive fruit quality and yield,trehalose+potassium fulvic acid from mineral sources has the best treatment effect.Compared with the control,the content of soluble solids,total soluble sugar,reducing sugar,soluble protein,vitamin C and lycopene in the center of the fruit treated with trehalose+potassium fulvic acid increased by 53.85%,40.99%,18.94%,20.51%,22.01%and 77.63%,respectively,and the organic acid content decreased by 10.91%,increased by 33.17%,and the relative income increased by 4100 RMB/667 m2.In summary,reasonable application of foliar fertilizer can promote the growth of watermelon plants,improve fruit quality,yield,and relative income.The optimal spraying concentrations for selenium fertilizer and trehalose are 0.050 g·L-1and 6g·L-1,respectively.The optimal application plan for foliar fertilizer combination is 6g·L-1trehalose+0.5 g·L-1mineral source potassium fulvic acid. |
PDF Full Text Request