Given the scarcity of water and the concentration of watermelon cultivation in areas with low productivity and high-water requirements, this research aimed to develop an economic plan for watermelon production using linear programming. This study revealed that watermelon production was concentrated in the Makkah region at 70.42%, followed by Riyadh at 13.98%. Watermelon productivity also varied between regions, with most regions exceeding the estimated productivity of the Jazan region, ranging from a minimum of 3.3% for the Najran region to a maximum of 37.1% for the Eastern Province. The total water used for watermelon production amounted to 274.12 million m3, representing 2.58% of the average amount of water used for agricultural purposes, which amounted to 10.62 billion m3 during the period 2019-2023. The proposed plan includes cultivating the same area of 25.53 thousand hectares, of which 21.23 thousand hectares are allocated to the Eastern Province, followed by Riyadh with an area of 3.47 thousand hectares, then Medina, Tabuk, and Hail with areas of 595.1, 154.4, and 81.1 hectares, respectively. The proposed economic orientation requires the use of 213.56 million m3 of water for watermelon production, representing 77.91% of the available water amount of 274.12 million m3. This leaves a water resource surplus of 60.56 million m3, representing 22.09% of the available water amount. Total watermelon production amounts to 701.05 thousand tons. Therefore, production under the proposed economic orientation increases by 90.7 thousand tons compared to its current counterpart, an increase of 14.86%. Finally, this study recommends the need to reconsider the agricultural policy for watermelon production, with the aim of increasing production and rationalizing water consumption.
Ghanem et al. (Wed,) studied this question.