Maximizing Forage in Winter Injured and Killed Stands
by Dan Undersander, Extension Forage Agronomist
When significant winter alfalfa stand damage occurs consider the following. The situations vary from low spots only in fields to significant portions of the fields.
I recommend the following:
- First, make sure that “dead” spots are actually dead and not just delayed:
- Dig a few plants and check the top 4 inches of the taproot for color and turgor. It should be an off-white (like the inside of a potato) and turgid (not ropy). If plants are off-white and turgid they are alive and just delayed.
- Also check fields that are putting out small shoots. Sometimes the dying plants will produce shoots 1 to 2 inches tall and then die. Again, dig a few plants and look for off-white and turgid taproots.
- Determine the percentage of field affected and manage accordingly:
- If small percentage, simply go over the affected areas with a drill as soon as possible and seed 10 lb/a with a 50/50 mix of Italian (annual) ryegrass and perennial ryegrass.
- If a moderate percentage of the field is affected and wanting to take first cutting and then reseed – immediately interseed Italian ryegrass (10 lb/a), take first cutting and then seed corn for maximum yield. An alternative in the southern half of the Wisconsin (especially if expecting dry conditions) would be to seed BMR sorghum-sudangrass (20 lb/a). Oats should be seeded for forage after Aug 1st.
- If a large percentage of the field is affected, seed corn or BMR sorghum-sudangrass before July 1st (20 lb/a). Corn will likely produce the most tonnage of any forage. Sorghum-sudangrass is a good choice if you expect dry conditions and/or above average temperatures (like last year). Alfalfa can be seeded into a different field at 10 to 12 lb/a with 6 lb/a tall fescue and 2 lb/a Italian (annual) ryegrass.