Response of garlic to irrigation water

The effect of irrigation frequency, irrigation water cutoff date, and amount of applied water on garlic yield was investigated. Project location was the west side of the San Joaquin Valley in California. Randomized plots replicated six times were used for the irrigation frequency and the cutoff experiments. Frequencies were one irrigation per week, one irrigation every 1.5 weeks, and one irrigation every 2 weeks. Cutoff dates were 12, 19, 25 May and 4 June. Sprinkler line-sources were used to develop relationships between garlic yield and applied water on sandy loam and clay loam. The highest yield occurred for the one irrigation per week treatment of the irrigation frequency experiment. The cutoff experiment showed highest yield for the 12 and May 12 cutoff dates. No yield response to applied water occurred for the line-source experiment in clay loam. Soil-moisture content data showed that garlic extracted soil-moisture deeper than 1.07 m to compensate for deficit irrigation. Garlic yield decreased linearly with applied water in sandy loam. The limited amount of stored soil-moisture in the sandy soil was insufficient to compensate for deficit irrigation. These results suggest that on sandy soil, weekly irrigations of an amount equal to the crop evapotranspiration plus losses due to irrigation inefficiencies should be applied. On fine-texture soil with the soil-moisture profile at field capacity in February, deficit irrigations can occur without reducing yield.