Dan Undersander, Extension Forage Agronomist
Department of Agronomy
UW-Madison College of Agricultural and Life Sciences
Phone (608) 263-5070, (608) 262-1390
3:01 – Total Time
0:16 – Summary of the dry season
0:56 – How to manage alfalfa in drought
1:28 – Rebuilding root reserves
1:48 – Alfalfa harvest decisions and insect control
2:51 – Log out
Dry weather and the alfalfa crop. We’re visiting today with Dan Undersander, Department of Agronomy, University of Wisconsin Extension in the College of Agricultural and Life Sciences, Madison, WI and I’m Sevie Kenyon.
Sevie Kenyon: Dan, sum up what’s happening to our alfalfa crop this season.
Dan Undersander: In the southern third of the state we’ve had significant yield reductions due to drought. First cutting was actually down about 25% or 30% because we were dry in March, when the alfalfa starts growing, when that’s usually the biggest cutting of the year, 40% of the yield, so that was a big loss. A lot of farmers got an acceptable second cutting in but then third cutting is largely going to be lost. Now, it’s important to remember that this is only the bottom two tiers of counties in the state, that from La Crosse and north we’ve had pretty good rain.
Sevie Kenyon: Dan, how are producers best able to manage what’s coming ahead?
Dan Undersander: As alfalfa’s drought stressed, it becomes stunted, or shortened, we get less stem height. It will still go into flower. It’s our recommendation is to really let the alfalfa go to full flower. Because you have less stem you’re going to have higher quality at later stages of maturity. So, a stunted, full flower alfalfa will have similar quality to a bud stage, normally growing alfalfa.
Sevie Kenyon: Dan, can you give us an idea of why it’s best to let it go to full flower?
Dan Undersander: Due to the drought, we have restricted root growth, we have reduced growth of the plant, and yet we still want to rebuild those root carbohydrates so that plant can come back and yield well when we do get rain again.
Sevie Kenyon: Are there some strategies or approaches people should use when it does start to rain?
Dan Undersander: At that point, whether we harvest it or not. If it’s over 10 inches it might be worthwhile harvesting. If it’s less than 10 inches it’s probably not worthwhile and it doesn’t hurt to stand in the next growth to leave it. So, decide on your harvest management based on the height of the alfalfa. The other thing to keep in mind is that we are having above average insect infestations this year; Potato Leaf Hopper, Army Worm, and some other insects. This always poses a difficult question because it’s really important to control those if we want that stand to come back, if we want the new seeding to come on. But it’s kind of hard for a lot of farmers to justify that and with the lack of yield potential, even though we probably need to control the insects. So do scout your fields for insects, think about that. If you think there is a potential for rain, if you see new growth coming in certainly get in there and control both Leaf Hopper and Army Worm if they’re present.
Sevie Kenyon: We’ve been visiting with Dan Undersander, Department of Agronomy, University of Wisconsin Extension in the College of Agricultural and Life Sciences, Madison, WI and I’m Sevie Kenyon.