INFLUENCE OF NITROGEN AND PHOSPHORUS RATES ON NUMBER AND QUALITY OF STRAWBERRY TRANSPLANTS

Abstract

This study was conducted at a private farm in Abo Ghalib, Giza Governorate, Egypt, during the two successive seasons of 2015 and 2016. The aim of this study was to determine the optimal requirements of nitrogen and phosphorus fertilizations for Festival strawberry cultivar nurseries, since it is an important cultivar which planted widely in Egypt for exportation as fresh or frozen fruits. Nursery mother transplants of strawberry cv. Festival (Super Elite plants) were taken out from the cold storage then dipped in 0.2% Rhizolex solution for 20 minutes and planted as plugs on the 1st and 4th of May in the first and second season, respectively. The transplants were spaced at 1.5 m between plants and 1.75 m between rows. Flowers were continuously removed from mother plants during the first month after transplanting. Drip irrigation system in the first two months was used then the micro sprinkler irrigation system (4 m x 5 m) was used. Four nitrogen fertilization rates (83, 100, 117 or 134 kg N/feddan) were added as ammonium nitrate fertilizer, while commercial phosphoric acid at rates of 0, 40, 60, 80 or 100 l/feddan to make five phosphorus fertilization rates (38, 62, 74, 86 or 98 kg P2O5/feddan) were used. A constant rate of potassium sulfate (96 kg K2O/feddan) was added. The fertilizers were added through the drip-irrigation system three times a week during the nursery period.