The recent rains followed by a dip in temperatures have led many farmers to express concern about early-planted soybeans.
As of April 20, approximately 40 percent of the Mississippi soybean crop was planted. Many growers have planted from early- to late-March for the past three years without any problems. I have attempted, however, to caution against getting in too big a hurry to plant, particularly regarding irrigated acreage, land lacking adequate surface drainage, and wide row plantings.
I have heard reports of frost injury on soybeans. I have looked at several emerged stands following the last three cold snaps and have yet to see any problems.
When a problem occurs, it is usually not just one particular factor causing the problem. At this time, I suspect something other than injury from cool weather.
Soybeans are extremely hardy. In the ground they are protected, but once emerged, broadleaf crops do not have their terminal growing points protected the way corn and other grass crops do.
Predicting the weather is not easy. If you and I could predict the weather, we would both be doing something else for a living.
The biggest concerns I have observed thus far are: planting too deep, excessive seeding rates, and the potential growth on early plantings — particularly in wide rows.
With the potential for less-than-desired seed quality this year, it is imperative that we do everything possible to minimize stress on emerging seedlings. Planting too deep is a common problem, particularly at this time of year.
Every so often a grower will tell me, “I planted my beans 3 to 4 inches deep in moisture and got a perfect stand.” This is rarely the case given the type of emergence of broadleaf crops. An optimum stand will not be achieved at these depths.
This time of year we often have heavy rains. Seed placed 1.5 inches deep often will appear to be forced deeper following a heavy rain and may have to try to push through crusting soil.
Planting deeper than needed subjects seed to cool soils, thus slowing emergence. It has been my experience that shallow plantings early help insure better stands. Keep in mind, I am talking about planting that occurs prior to day and night-time temperatures increasing.
Planting this time of the year does not compare to planting in June. As temperatures begin to increase and weather fronts begin to spread out, it will be essential to place seed in adequate moisture.
The time of the year, day and night temperatures, the five-day weather forecast, and seed quality must be considered when determining planting depth early.
Although sporadic, I have already seen small grasshoppers in some fields. Grasshoppers have been more prevalent in fields where burndowns were applied late or were put out at planting.
Several options exist but the two most effective treatments are Dimilin and Orthene. If you see some grasshopper activity, but the crop is not yet emerged or there is little feeding on the foliage, add 1 ounce of Dimilin to your burndown or first postemergence herbicide application. If feeding is heavy, consider using 0.3 pound of Orthene. The choice depends entirely on how fast you need to kill this pest.
I had hoped grasshopper populations would be less this year and they may be. I am surprised, however, to see treatable populations in some fields already. You will probably not observe a problem where tillage has occurred or burndowns were applied early. On the other hand, where a lot of dead or dying vegetation is present, the potential for grasshopper pressure exists.
Alan Blaine is the Mississippi Extension soybean specialist. e-mail: [email protected].