NDSU Sunflower Information
SUNFLOWER PRODUCTION
The "Sunflower Production Guide," NDSU extension publication A1995 includes information about hybrid selection, understanding the growth and development of sunflower plants, field selection and preparation, planting date guidelines, seeding rates, frost tolerance and damage, soil fertility requirements, weed control, insect pest and disease management, drying and storage.
SUNFLOWER GROWTH AND DEVELOPMENT
Growth and development of sunflower is mainly driven by growing degree day (GGD) units. GDD for sunflower is calculated as follows: Daily Sunflower GDD = ((Daily Max Temp °F + Daily Min Temp °F)/2) - 44 °F. If the daily maximum or minimum temperature is less than 44 °F the number in the formula is set at 44 °F. Table 1 provides an indication of how many GGD’s are needed to reach the different development stages in sunflower. The GGD’s needed are an estimate and may differ between hybrids and growing conditions. The GGD’s and estimated growth stages can be calculated for any location in ND by using the NDAWN sunflower GGD and growth stages model. Location and planting date can be selected to calculate local GGD’s and estimate of growth stage of the crop
Table 1. Selected Growth stages and GGD associated with plant development.
Growth Stage |
Description of growth stage |
Accumulated GGD |
V10 |
Vegetative sage with 10 true leaves |
557 |
V20 |
Vegetative sage with 10 true leaves |
908 |
R1 |
Terminal bud miniature floral head |
1048 |
R5.1 |
Beginning flowering 10% of head area |
1609 |
R6 |
Flowering complete ray flowers wilting |
1889 |
R 9 |
Bracts yellow and brown, physiological mature |
2310 |
For stages of sunflower development see publication A1145
SUNFLOWER LINKS
Fertilizing Sunflowers and Sunflower Nitrogen Calculator
Sunflower Disease Diagnostic Series and web version
Sunflower Best Management Practices, SDSU
Sunflower Treated with Avipel Bird Repellent (2008)