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.

Key words: Drought management, irrigation methods, watermelon cultivar.