Effects of different nitrogen rates on yield and leaf nutrient contents of drip-fertigated and greenhouse-grown cucumber

Abstract

The aim of the present study was to investigate the effect of the nitrogen concentrations (0-100-150-200 mg N L-1) and their application frequencies (one and twice per week) on yield and leaf nutrient content of drip-fertigated cucumber on sandy-loam soil under the glasshouse conditions and also to determine whether there was a difference between the application of low nitrogen concentrations (50 and 100 mg N L-1) continuously and high nitrogen concentrations (200 and 250 mg N L-1) twice per week in terms of investigated characteristics. The highest yield (75.21 ha-1) was obtained with the application of 200 mg N L-1 nitrogen twice per week. Irrespective of application frequency, the highest total yield was produced with 200 mg N L-1 nitrogen concentration (71.2 t ha -1). Nitrogen application twice per week also resulted in higher early yield compared to once a week application. Nitrogen concentration and application frequency also affected fruit number. The highest fruit number was obtained with 200 mg N L-1 nitrogen concentration (59.4 fruit m -2). While the chlorophyll content of the leaf was affected by only nitrogen concentration, the nitrogen (N) and phosphate (P) content of the leaf were affected by both the nitrogen concentration and the application frequency. Whereas potassium (K) content of the leaf was influenced by the application frequency of nitrogen. The N, P and K contents of the leaf were within the sufficiency level. In the study where different nitrogen concentrations were applied at each irrigation (continuously) or at twice per week, the best result obtained with application of 200 mg N L-1 nitrogen concentration twice per week (86.6 t ha-1). Based on these results it was concluded that application of 200 mg N L-1 nitrogen twice per week irrigation together with 200 mg K L-1 +40 mg Mg L-1 +2.5 mg Fe L -1 once a week was adequate in terms of yield and leaf nutrient contents. Also, application of lower nitrogen concentrations at each irrigation did not produced greater yield when compared to 200 mg N L-1 nitrogen applied twice per week. It can be concluded from this result that there is no need to continuous nitrogen supply in fertigation. © 2006 Asian Network for Scientific Information.