Onion‐Seed Yield and Quality as Affected by Irrigation Management1

Abstract

AbstractThe effects of soil moisture, sprinkler irrigation, and misting (5 min at 30‐min intervals) on hybrid onion‐seed (Allium cepa L.) production were evaluated at Kimberly, Idaho. Sprinkling and misting treatments were included to determine if sprinkler irrigation could be used for onion‐seed production, and if evaporative cooling (misting) would alleviate the scalding of umbels at excessively high temperatures. Results showed that reasonable onion‐seed yields could be obtained with sprinkler irrigation in spite of anticipated adverse effects on pollination. In areas with high daytime temperatures, misting could be used to cool the umbels, as much as 15 C for about 20 min, although it does not seem necessary for the low 32 to 35 C daytime temperatures at Kimberly. The highest onion‐seed yields were obtained with the furrow‐irrigation treatment where water was applied when tensiometers at 20‐cm depth read about 0.5 bar soil moisture tension (furrow adequate). The addition of misting to furrow irrigation decreased seed yields 19%. Furrow irrigating at 0.4 bar decreased yields 26% below those obtained with irrigation at 0.5 bar. While overirrigation adversely affected yield, irrigation treatment had only a slight effect on seed weight and vigor.