Performance of Grapefruit Under the Ecological Conditions of Central Sudan I. Growth, Flowering .and Yield

Abstract

Growth, flowering, production efficiency and fruit quality of 13 grapefruit (Citnls paradisi) cultivars on a sour orange root stock were evaluated for over a 15-year-period in central Sudan. The newly introduced cultivars showed vigorous vegetative growth and were slow to come to bearing as they were nucellar line selections compared the locally adapted cultivars. Two peaks of flowering were detected with a major peak during winter (December-March) , induced by temperature rhythun, and a minor one coinciding with the rainy season (June-September). Both leafy bouquet types of bloom were observed, but the leafy type was dominant and resulted maxunum fruit set. During early cropping seasons, the newly introduced cultivars trailed the locally adapted ones in yield. However, by the 6th Croppuing season (11 years after planting) all trees apparently reached full cropping capacity and the newly introduced cultivars started to excel the locally adapted ones. The yield ranged from 22.4 to 40.8 t ha-1 during this cropping I season.