May 31, 2019, 9:00 AM
Warm and dry weather has finally arrived and will hopefully continue. Some growers will just be getting started, but for others, their sunflowers have been sitting in the cold, wet ground for 14-21 days. We hear about growing degree days (GDD) a lot with corn, but not as much as sunflowers. How many GDD are actually needed from planting to emergence for sunflowers? Are there any concerns for growers that have had their sunflowers sitting in the soil un-emerged?
Figure 1. Sunflower in the VE
(emergence) stage with cotyledons
Current accumulated growing degree days (AGDD) for various sunflower locations in ND, May 13th-27th
*Departure from normal
Figure 2. Downy Mildew symptoms
apparent by the yellowing of the leaves.
If you were able to get your sunflowers planted early, make sure to keep an eye on them now as they start emerging to know if there could be any potential stand concerns.
Seed treatments, like the new Plenaris®, can help with issues
such as downy mildew. Besides fungal pathogens, there are still other concerns that may arise. Cutworms (especially now that it’s warming up), wireworms and soil crusting are just some examples that can contribute to stand loss.
Warmer weather this week should give the sunflowers that were planted early enough growing degree days to emerge out of the ground. Make sure to check your fields after emergence to ensure that a good stand was established.
Figure 3. Sunflower seedlings cut at the soil surface from cutworms
Author: Nuseed Product Development Manager Alison Pokrzywinski
NDSU Sunflower Production Guide, revised September 2007