The 2010 growing season was warmer and slightly wetter than normal through the majority of the spring. The month of May was considerably drier than normal, though June’s rainfall exceeded 30-year averages. No effect was apparent on germination rates. Accumulated growing degree days (GDDs) for the sunflower season totaled 3,120 from the beginning of June through the middle of October, when the sunflowers were harvested, which was 264 higher than the 30 year averages (table 1). These data were recorded at weather stations in close proximity to the research site.
Vermont, University of Vermont
Darby, Heather; Halteman, Philip; Cummings, Erica; Gervais, Amanda; and Madden, Rosalie, "Sunflower Seeding Rate x Nitrogen Rate Trial Report" (2010). Northwest Crops & Soils Program. 275.