Todd Vagts
Iowa State University Extension
Field Crops Specialist
1240 D. Heires Avenue Office: 712-792-2364
Carroll, IA 51401 Cell: 712-249-6025
Email: vagts@iastate.edu Fax: 712-792-2366

Most of the corn across the region is now at or past the V7 leaf stage. Although the ear shoots (potential ears) were formed just before tassel formation (V5), number of ovules (potential kernels) on each ear and the size of the ear are determined at the V12 stage. The number of rows of kernels per ear has already been established, but the determination of the number of kernels per row will not be complete until about one week from silking or about V17.

Oat fields across the area are at or beyond the heading stage. Many questions have been asked regarding when the best time is to harvest oats for silage. The answer is anytime between late boot and mid dough stage. The following information addresses the oat harvest debate.

Small Grains for Silage or Hay. Nebraska Extension publication (G84-696-A).

Boot—Head remains inside stem and visibly distends sheath of flag leaf. Head of main stem usually enters boot stage first, followed by tillers. This stage lasts about 7 to 10 days. Heading and Flowering—Head emerges above flag leaf. A few days later flowering occurs (anthers emerge to shed pollen). Together, the two stages last about 10 to 14 days. Milk—White, milky fluid fills the kernel, some leaves die, embryo develops fully. This stage lasts 7 to 10 days. Dough—The kernel has dough consistency, leaves are dying, plant changes from green to yellow. This stage lasts 7 to 10 days.

The forage quantity increases and the quality decreases as the plant matures

• Boot: Digestible protein and energy percentage is highest, but dry matter production per acre is low. When harvested at this stage of growth, small grain forage approaches mid- to early bloom alfalfa in feed value.
• Heading to flowering: When harvested in the heading to flowering stage, small grain forage should be equal to or better than early cut grass forage.
• Milk-stage silage is the least palatable to livestock, and usually produces slower and less efficient gains than dough-stage silage.
• Dough-stage silage, although lowest in crude protein, produces the greatest forage yields and usually the greatest total digestible nutrient yield per acre.

Variegated cutworms continue to be found in newly harvest alfalfa fields, particularly under windrows. Be on the lookout for these pests. Refer to last weeks crops newsletter for treatment thresholds.

Black and Variegated cutworm are causing problems in soybeans across IA. Be vigilant for these pests in your soybean fields.

Use the following table to help determine when to scout and to track the development of the ECB.

*From European Corn Borer - Ecology and Management. Publication NCR-327, page 7. Available from ISU Extension Distribution Center (515-294-5247).