- Pest Type: Weed
- Crops Affected: Wheat, Cotton, Potatoes, Soybeans, Corn
- Scientific Name: Zea mays
- Pest Order: Poaceae
Volunteer corn is a tall, erect, robust, monoecious annual grass, generally 1-3 m tall from a single base. General appearance is the same as commercially grown corn, but not planted in rows. When arising from ears, rather than single seeds, the volunteer will appear in clumps.
Reproduction is by seed. Seed is generally scattered at corn harvest, when harvesting equipment misses some kernels or grain is spilled.
Leaves are rolled in the bud and auricles are absent. Blades are large, linear to lanceolate, and flat.
Immature plants are usually stout and robust, with large, flat linear leaves having a prominent, stiff midrib. The upper surface of leaves are covered with hairs, while the under surface is hairless and shiny. Leaves are distichous (two ranks of single leaves borne in alternate positions) with overlapping sheaths and long, broad blades. Leaf blades are separated by elongated internodes.
The mature volunteer corn plant is monoecious (male and female flowers separate, but on the same plant) and is a large, robust, and stout annual grass. Although the volunteer corn plant usually has a single dominant stem/stalk, it may have a few basal tillers.
Fibrous root system with prominent brace roots.
Volunteer corn plants are monoecious; i.e., male and female flowers are separated on the same plant. The male flower (tassel) is a loose panicle at the top of the plant/stem and sheds pollen. The female inflorescence (ear) is about midway down the plant and produces the seeds pairs of rows on the cob.
Stems/stalks persist through the winter.
Volunteer corn grows in fields where corn was grown for grain the previous year. Thus, it is nearly always in agronomic fields and is commonly observed in soybean fields which are in corn-soybean rotations.
Since corn is grown throughout the United States, southeastern Canada, and in most other countries around the world, volunteer corn can be found in all these areas.
In seedling stages, wild-proso millet and shattercane seedlings can look very similar to volunteer corn. Wild-proso millet seedlings have narrower leaves than volunteer corn and are considerably more hairy.