Supplemental irrigation effects on yield of two watermelon (Citrulus lanatus) cultivars under semi-arid climate in Kenya

Abstract

The objectives of this study were to determine the effect of the supplemental irrigation using drip, sprinkler and 
furrow methods on two watermelon cultivars (Charleston grey, and Sugar baby) by studying their growth, yield and 
quality (Brix index) and economic feasibility under semi-arid climate in Kenya. Cultivars irrigated with drip produced 
significantly more fruits than those under either sprinkler or furrow. The highest total economic yield of 4.05 Mg/ha 
in the short rain season (SRS) and 4.95 mg/ha in the long rain season (LRS) was obtained in ‘Charleston grey’ 
irrigated by drip. The average fruit weight was 6.07 kg in the SRS and 7.42 kg in the LRS. The highest net benefit was 
US$ 493.3/ha in the SRS and 706.1/ha in the LRS. A 2 or 4-week starter irrigation, drip supplemental irrigation 
boosted ‘Charleston grey’ yields by 1.78-fold, if water stress occurred during the late vegetative growth. 
Supplemental irrigation during late vegetative growth decreased the total soluble solids in fruits. Total soluble 
solids concentration was 5.93Brix in the SRS and 8.16Brix in the LRS. The furrow irrigation supplied the most 
water to the crop resulting in the lowest total soluble solids of watermelons.