Effect of Levels and Methods of Potassium and Phosphorus Fertilization on Yield, Fruit Quality and Chemical Composition of "Khalas" Date Palm Cultivar

The present study was carried out during 2010 an d 2011 seasons at the Research and Agricultural Experimental Station, King Saud University, Saudi Arabia in order to study the effect of potassium and phosphorus fertilization rates applied either alone or in combinations with each other on leaf mineral co ntent , yield and fruit quality of Khalas date palm cultivar. Potassium and phosphorus rates were added in either; one, two or three equal doses in 15 th of February ( before flowering), 15 th of April (after fruit set) and 15 th of May (during fruit maturity ). The results showed that potassium and phosphorus fertilization increased the fruit set and yield and improved the fruit physic al characteristics (fruit weight, volume, length and diameter ) at beser stage, and chemical characteristics (TSS, acidity and s ugars contents ) at Tamer stage , especially with high levels of potassium fertilization. The high level of potassium fertilizati on increased the pinnae N, P, K and Fe content s , while decreased the Zn and Mn content s . Thus, it is recommended to add the high level of potassium (2 Kg potassium sulphate ) and phosphorus (1.5 Kg calcium super phosphate) at three and two equal doses, respectively to increase the yield and fruit quality of "Khalas" date palm grown under the present conditions. ( R. S. Al - Obeed; H.A. Kassem and M.A. Ahmed . Effect of Levels and Methods of Potassium and Phosphorus Fertilization on Yield, Fruit Quality and Chemical Composition of "Khalas" Date Palm Cultivar Life Sci J.2013;10( 4 ): 1111 - 1118 ). (ISSN: 1545 - 1003). http://www.lifesciencesite.org . 146