NUTRITIONAL STATUS OF FOSTER GRAPEFRUIT IN SUDAN CENTRAL CLAY PLAIN

A detailed survey was carried out for 8 Foster grapefruit (Citrus paradisi Macf.) groves in Sennar area (13˚ 37΄ N, 33˚ 37΄ E) representing Sudan Central Clay Plain. Trees were budded on Sour orange (Citrus aurantium L.). Soil and leaf samples were collected and analyzed according to standard procedures. Soil analyses included particle size distribution, pH (paste), ECe, SAR, N, P, K, Ca, Mg, Na, Zn, Fe and Mn. Leaf nutrient  levels  determination included N, P, K, Ca, Mg, Zn, Fe and Mn. Yield per tree was recorded for one season and quality parameters were measured for fruits sampled from representative trees. Results indicated that, soil texture of the orchards ranged between clay and clay loam. Although the orchards were receiving the same cultural practices, yet, they were significantly different in some soil and plant constituents. All orchards were non-saline and non-sodic of slightly to moderately alkaline reaction. Soil and plant were deficient in nitrogen and zinc with high leaf phosphorus, magnesium, iron and deficit calcium levels. Mean fruit yield ranged between 0.93 and 7.76 tons ha^-1 with an average of 4.35 tons ha^-1, which is considered lower than world average. A low % TSS (total soluble solids), low ascorbic acid content and high % green color on fruit surface are evidents of low quality fruits. The low yield and poor quality fruits in this area were attributed to unsuitable soil conditions and the poor management practices