Effects of Different Nitrogen Fertilizer Application Rates on Yield and Nutritive Quality of Cucumber in Soilless Culture

Experiments were conducted to study the effects of different nitrogen fertilizer application rates on the fruiting period,yield and nutritive quality of cucumber varietyLufengcultivated in the mixed substrate of cassava residue. The results were as follows:( 1) When the application rate of nitrogen fertilizer( urea) was enhanced in the range of 0 ~ 15 g / bucket,the fruiting period of cucumber became earlier and extended,the yield,single-fruit length,single-fruit weight,soluble solid content and soluble sugar content were increased,and the fruit acidity was decreased. The single-fruit length,single-fruit weight,and the contents of soluble solid,soluble sugar and nitrate in fruits in all treatments decreased with the consumption of nitrogen fertilizer in the substrate.( 2) When 25 g / bucket urea was applied,the contents of soluble sugar and nitrate in fruits at later fruiting stage were higher than those at flourishing fruiting stage,but the fruit acidity was lower.( 3) As the application rate of urea was 15 g / bucket, the fruiting period was the longest,the plot total yield was the highest( 25. 14 kg),and the nutritive quality of fruits was better.