CROP
DEVELOPMENT: Emerges 7 to 12 days after
planting. Flower buds appear 30 to 40 days after planting.
Flowering occurs about 55 to 65 days after planting, and lasts
for 7 to 10 days, depending upon temperature. Maturity occurs
about one month after flowering is completed. Matures in 95 to
110 days, depending upon hybrid and accumulated growing degree
days (GDD's). Typical plant height is 60 inches to 90 inches.
SOILS:
Adapts well to many soils. Fertile, well drained soils are
usually best.
PLANT
POPULATION: When seeded as a row crop in 30
inch rows, the desired plant population is 15,000 to 18,000
plants per acre. Seed rates of 3 to 5 lbs/acre are typically
sufficient to achieve these populations, depending upon seed
size. There are approximately 4,300 seeds/pound.
PLANTING
DATE: Early May to late May is typical.
Seedlings have some frost tolerance.
SEEDING
DEPTH: 1.5 to 2.5 inches.
FERTILITY
REQUIREMENTS: 50 lbs. of N per 1000 lbs. of
yield. Similar to small grains in phosphorous use. Use of 10 to
15 lbs/acre of sulfur is suggested.
WEED
CONTROL: Soil applied herbicides include
Eptam, Sonalan, trifluralin (Treflan), and Prowl. Post emergence
options include Assert and sethoxydim (Ultima 160).
CHEMICAL
CARRYOVER: Sensitive to carryover of
sulfonylureas (e. g. Glean, Ally), also sensitive to atrazine
and picloram (Tordon).
ROTATION:
Usually between small grains.
WATER USE:
Fairly drought tolerant, deep rooted crop.
INSECTS:
Sunflower midge, red seed weevil, gray seed weevil, stem weevil,
sunflower beetle, banded sunflower moth. Numerous insecticides
are labeled for insect control.
DISEASES:
Sclerotinia (white mold), downy mildew, alternaria, rust, head
rot, phoma black stem. Diseases are typically managed by using
good rotation practices. Seed treatment with Apron is beneficial
in preventing downy mildew.
HARVEST:
Sunflowers are typically harvested 30 to 45 days after maturity,
since it takes this long for the plant to dry down. Use of
sunflower pans on a straight header attachment is the most
common practice. Cylinder speeds of 300 to 500 rpm are typical,
depending upon moisture content. Typical concave settings are
1" in front and 0.75" in rear. Typical sieve settings
are 1/2" to 5/8" on top, and 3/8" on bottom. Seed
moisture should be less than 10% for storage. It is important to
avoid cracking and hulling. Drying is quite typical.
MARKETS:
Edible whole sunflower seeds. Hulled seeds (or nut meats) are
used in breads, cereals, salad toppings, and other condiment
applications.
TYPICAL
YIELDS: 1000 to 1500 lbs/acre. Yields of
2000 lbs/acre are possible.
VARIETIES:
Numerous hybrid varieties are available.
