Effect of partial root-zone drying drip irrigation system on valencia orange trees

الملخص EN

This study has beencarried out during 2014/2015 and 2015/2016seasons to improve yield, fruit quality and water use efficiency on ten years old Valencia orange trees (Citrus sinensesL.), budded on sour orange rootstock (Citrus aurantium L.) under sandy loam soil at Belbeis region – El Sharqia Governorate, Egypt.

The investigation aimed to study the effect of time period of alternating wet and dry sides by using partial root-zone drying irrigation (PRD) system on flowering, fruit set, yield, fruit quality, water relations and water use efficiency of Valencia orange trees using Nile river water to determine the most effective treatment.

The data reveal that, the longer period of alternating wet and dry sidesby using partial root-zone drying irrigation system (PRD) improved total number of buds, number of leaf buds, percentage of leaf buds, number of flower buds, number of opened buds, opened buds percentage, leaf free water content, chlorophyll a and carotenoids contents, total number of inflorescences, number of leafy inflorescences, number of solitary flowers per twig as well as yield in both seasons.

The most effective treatment at partial root-zone drying irrigation system (PRD) was alternating wet and dry sides every four irrigations which reached 21.68 and 21.93tons fruit per feddan in the first and the second seasons , respectively.