Maximizing Forage in Winter Injured and Killed Stands, Spring of 2013
Dan Undersander, Forage Agronomist
We are getting reports of significant alfalfa stand damage across Wisconsin and southern
Minnesota. The situations vary from low spots only in fields to significant portions of the fields.
I recommend the following:
1) First make sure that “dead” spots are actually dead and not just delayed:
a. Dig a few plants and check the top 4 inches of the tap root 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.
b. 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.
2) Determine the percentage of field affected and manage accordingly:
a. 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.
b. If a moderate percentage of the field 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 sorghumsudangrass (20 lb/a). Oats should be seeded for forage after Aug 1.
c. If a large percentage of the field is affected, seed corn or BMR sorghum‐sudangrass
before July 1 (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.