Farm Horizons, May 2005
Take a good look at your alfalfa
By Myron Oftedahl, CCA
It will be a good idea for you to evaluate your alfalfa stands this spring.
The ice sheets and lack of snow cover, in combination with cold temperatures this past winter, have set the stage for winter injury to alfalfa stands.
Ice sheets smother the plants, preventing air exchange and release of toxic compounds, which will kill the plant.
Soil temperatures below 10 degrees may also lead to winter injury or kill.
Evaluate damage by digging up a few crowns and split the crown and root with a knife. A healthy root will be firm and white.
Injured roots may be soft, gray, and water-soaked, or brown. The brown areas may resemble cork. If less than half of the plant is injured, it probably will survive.
By the time this is printed, if the alfalfa is six inches tall, it will be okay.
You can still evaluate stand counts at this time, by counting the number of healthy stems per square foot that are over six inches.
Guidelines are: if less than 39 stems/sq. ft., consider plowing under; 40-55 stems, you can expect some yield loss; and over 55 stems/sq. ft., no yield loss is expected.
Since you are out in the field, the end of May is a good time to evaluate your corn and soybean stands.
Are they even in height, is the spacing even, are there plants wilted or chewed off, are there plants that germinated and began growing and are now dead?
What is your weed control like? Is the preplant or preemerge product working? Do you need to rotary hoc or harrow the field to help the chemical? What weeds do you still need to control?
It will be critical to spend time in your fields this summer, if you are going to protect the yields.
Aphid egg counts are being reported as the highest ever. The soybean rust scare wi1l, and should, be on everybody’s minds this summer.
I would suggest to you that you commit at least one day a week to visit your fields. I don’t mean driving by them, either. I mean walking out into the field and checking the weed control, and examine the soybean canopy for insects or rust.
Watch corn fields for cutworm, cornborer, and adult corn root worm beetles.
These questions need to be answered in order to make good management decisions, and to evaluate your cropping program.
Have a safe and profitable season.