INFLUENCE OF FERTILIZERS ON YIELD AND QUALITY OF A YOUNG CITRUS ORCHARD IN KENYA

Citrus fruits have been cultivated in Kenya for many years, particularly on sandy soils at the coast (Jackson, 1948). Most trees have been raised from seed, except in recent years when propagation by budding, using improved cultivars, has gained popularity. Small domestic scale gardening has also included citrus cultivation. Oranges - Citrus sinensis, grapefruit - Citrus paradisi (Macf.), lemon Citrus limon (Linn.), limes - Citrus aurantifolia (Swingle) and tangerines - Citrus recticulata (Linn.) are the most important kinds of citrus fruit grown in Kenya.

Citrus growers have applied manure and fertilizers in growing these trees and some have used, or even modified fertilizer programmes from other countries, or based their recommendations on programmes suitable for citrus production in Kenya. No systematic studies appear to have carried out on fertilizer requirements for citrus in Kenya.

The success of any fertilizer programme is dependent upon the nutrient requirement of the crop and upon the nature and characteristics of the soil in which it grows. Most soils in Kenya are very deficient in phosphate and citrus grown on these soils, without supplementary phosphatic fertilizers, are very low in quality (Johnson, 1966). For this reason, a fertilizer study programme will undoubtedly assist in solving the nutritional problems of the citrus industry in Kenya.