Response of sweet potato (cv. Georgia Jet) to water limitation under drip and sprinkler irrigation

Sweet potato is moderately tolerant to water stress, but irrigation can stabilize and increase production potential. This study evaluated sweet potato yield as affected by irrigation quantity and frequency, comparing drip and sprinkler systems under field conditions at the South Agricultural Research and Development Center, Eshkol, Israel. In 2020, treatments consisted of two irrigation amounts: full irrigation (100% of actual crop evapotranspiration, ETc) and 60% of full, applied using drip or sprinkler irrigation. In 2021, irrigation frequency was examined using daily drip irrigation (Drip 1 × 1), daily drip irrigation switched to every two days at 40 days after planting (Drip 1 × 2), and daily sprinkler irrigation switched to every two days at 40 days after planting (Sprinklers). In 2020, sprinkler irrigation significantly reduced the percentage of marketable storage roots and fresh storage root mass by 34% and 17%, respectively, compared with drip irrigation. In 2021, Drip 1 × 1 irrigation increased the total number of storage roots, the number of marketable storage roots, the percentage of marketable storage roots, and the marketable yield (mass of storage roots between 150 and 600 g) relative to the sprinkler irrigation treatment. Drip 1 × 2 reduced water productivity (yield per unit of irrigation water applied), total, and marketable storage root numbers relative to Drip 1 × 1. Sprinkler irrigation was associated with reduced fresh storage root mass, total storage root yield, and water productivity, the latter likely due to lower yields and greater evaporative water losses. Sprinklers produced a greater proportion of small storage roots than drip irrigation. Overall, the findings indicate that, under the environmental conditions of this study, sweet potato productivity can be maximized when provided with sufficient and frequent irrigation water supply through drip irrigation.