Irrigation of Safflower in Northern Utah.

Most safflower in Northern Utah and Southern Idaho is grown under dryland conditions; however irrigated safflower can provide higher yields.  Two perceived concerns with irrigated safflower are an increase the severity of alternaria leaf spot disease and delayed maturity in the fall.  Safflower irrigation research was conducted at the Utah State University Greenville Farm in North Logan, Utah (41°45'47.00"N, 111°48'58.79"W, 4595 feet elevation) in 2013 and 2014.  The objectives of the studies were to determine impact of irrigation on yield and alternaria leaf spot disease.  Safflower yields up to 4,000 lbs./acre were obtained when adequate water and fertility were available for the safflower.  The soil moisture, irrigation, and yield data indicate that adequate soil moisture during vegetative growth and flowering stage (up through first week in July for April planting) is important to produce high irrigated safflower yields.  The anaylsis also looked at the oil content and seed quality.  In this study, the application of a fungicide did not significantly impact yield and provided only minor improvements in seed quality