Managing Windrow Disease In Alfalfa

Managing Windrow Disease In Alfalfa

June 19, 2009

Rained-on hay plagues all growers eventually and the "windrow diseases" that often follow present lingering problems.

Windrow disease - that's what I call the stripes of field where alfalfa windrows remained so long that regrowth was delayed.

Windrow disease presents special challenges. Weeds often invade, requiring spraying to maintain quality and protect stands. And during the next growth period, plants that were not smothered regrow rapidly, while plants underneath the windrow suffer delays. Part of the field often will begin to bloom while windrow-stressed plants are still short and tender. Then growers have to choose between harvesting when the first plants begin to bloom or waiting until the injured plants are ready.

Two factors can help you determine when it's best to cut:

  1. the health and vigor of your stand
  2. the nutrient needs of your livestock.

For example, is your alfalfa healthy and regrowing well? If not, wait to cut until stunted plants begin to bloom so you can avoid weakening them even more. If your alfalfa is in good condition, cut when it will best meet the needs of your animals.

Dairy cows need alfalfa that is cut early, so harvest when the first plants begin to bloom. Regrowth of injured plants may be slow after cutting, but this sacrifice is needed for profitable milk production. In contrast, beef cows do not need such rich hay. Let stunted plants recover, then cut when they are ready to bloom.

By the next cut, growth will be more uniform, plants should be healthy, and production will be back to normal.

Bruce Anderson
Extension Forage Specialist