Influence of some fertilizer treatments on productivity and fruit quality of strawberries

Abstract

Field experiment was carried out at Shebeen El-Kanater region, El-Qulybiya Governorate, Egypt, during 2005/2006 and 2006/2007 seasons, on fresh strawberry plants cv. Camarosa. This work aimed to determine the optimal N and K fertilizer levels and investigate the effect of nitrogen sources on the productivity and fruit quality of strawberries. The experiment was arranged in split-split plot design with three replicates. Three nitrogen levels (100, 80 and 60 kg N/fed.) were arranged in the main plots, three nitrogen sources (100% ammonium sulphate, 100% poultry manure and 50% poultry manure + 50% ammonium sulphate) were distributed in the sup-plots and two potassium levels (150 and 200 kg K2O/fed.) were assigned in the sub-sub plots. Results showed that increasing nitrogen levels resulted in increasing of vegetative growth parameters (plant length, leaf number and leaf area) and early marketable yield but decreased number of flowers per plant and total marketable yield. Increasing nitrogen levels also increased average fruit weight but decreased fruit firmness and had non-significant effect on T.S.S %. Results also showed that 100% ammonium sulphate (as a nitrogen source) was the remarkable treatment for vegetative growth, fruit yield and quality of strawberries, followed by 50% poultry manure + 50% ammonium sulphate treatment. High potassium level (200 kg K2O/fed.) produced the highest values of vegetative growth, flowering, fruit yield and quality. Concerning the effect of interaction among nitrogen levels, nitrogen sources and potassium levels, the results revealed that application of 60 kg N/fed. of 100% ammonium sulphate and 200 kg K2O/fed. was the best treatment for early, total marketable yield and fruit quality characteristics.