Seeding Rate and Row Spacing Effects On Growth and Yield of Safflower.

Safflower has been an important crop in Utah’s dryland production systems for decades.  As the demand for safflower oil rises, many growers are considering transitioning their safflower acres from birdseed to oil.  With that comes a need to evaluate agronomic recommendations for these new varieties.  The objective of this study is to determine effect of plant population and row spacing on growth and yield of three safflower varieties.  Studies were conducted at North Logan (irrigated) and Blue Creek (dryland), UT in 2010 and 2011.  Treatments were arranged in a randomized complete block split-split plot with row spacing (15, 46, and 76 cm) as the whole plot, variety (S-208, Hybrid 9049, and CW 90L) as the sub-plot, and seeding rate (6.7. 13.4, 20.2, 26.9, and 33.6 kg/ ha^-1) as the sub-sub-plot.  Treatments were replicated four times.  Safflower stem density, pod counts, yield, and seed characteristics were determined.  Variety had little to no effect on safflower yield but greatly influenced quality.  Safflower yields were highest in 15 cm rows and 46 and 76 cm rows did not differ from each other.  Seeding rate did not influence the number of pods m^-2 or yield at either site.