Agriculture Reference
In-Depth Information
GROWING FOR SEED
Except for measures to isolate multiple varieties, there is no difference in sun-
flower cultivation when growing for seed.
HARVEST
After fertilization, seeds grow until the heads are full. Cut off seedheads as soon as the
petals have fallen off, and dry with the seed side up. Make sure the drying site is free of birds; some-
times birds are so eager to eat the seeds, they will even fly into rooms to harvest them for themselves.
Remove seeds from heads when they are completely dry. This can be done by hand for smaller quantit-
ies by rubbing seedheads together. For larger quantities, stretch hardware cloth with a mesh size larger
than the sunflower seeds over an empty bucket or garbage can. Rub seedheads across the mesh until
the seeds fall out and drop into the container. Dryness test: try to bend the seeds. When they break,
they are dry enough for storage. Lay seeds out flat in cardboard boxes in a warm, shady place safe
from mice to dry.
SELECTION CHARACTERISTICS
The many available cultivars differ from each other both in superfi-
cial traits (size and color of flowers, number and size of flower heads, etc.) and internal traits (oil con-
tent, fiber content, etc.). Home gardeners usually grow varieties with beautiful, conspicuous flowers.
Select true-to-type plants for propagation. An important criterium for home gardeners as well as large-
scale growers is plant stability.
DISEASES AND PESTS
Diseases and pests are rarely an issue in the home garden. Birds can be a nuis-
ance, picking sown seeds out of the ground and seeds from heads; cover with bird or insect netting, if
necessary. Snails and slugs eat the seedlings. Powdery mildew can be a problem where sunflowers
have been too densely sown and the air is calm.
CULTIVATION HISTORY
Sunflowers, like Jerusalem artichokes, are an old American Indian crop and
another of the few crop species that originate in North America. Archaeological finds of sunflowers
date back 5,000 years. A research team in Tabasco, Mexico, found one (!) seed in 2001 at an archae-
ological dig, which has brought up the question of whether the sunflower was in fact originally do-
mesticated in Central America. The sunflower appears to have arrived in Europe in 1510 with the
Spaniards and was first grown as an ornamental. An Englishman discovered the sunflower's potential
as an oil plant in 1716, but his patent arose no interest. Commercial sunflower oil production began in
the Ukraine around 1835 and has since spread around the world. In the last several years, the EU has
subsidized sunflower cultivation as a renewable resource. It is also being increasingly used as a green
manure and bee forage plant. Seeds of recently bred varieties have an oil content of up to 50%. Hybrid
varieties are being grown more and more.
