Are my soybeans healthy?
Jul 11Are my soybeans healthy?
We have reached the stage in soybean development when nodules are forming. Every year I customers that are concerned that their soybeans are yellowing. We received a nice rain in most areas and warm temperatures have boosted crop growth. In just a few days things have changed. Soybean plants have used up the native nitrogen in the soil and they are in the transition phase where the nodules can fix atmospheric nitrogen to supply the plants’ needs. In about 7 days these fields will be a healthy green colour. We are seeing the early planted fields progressing very well and greening up nicely. Dig up a few plants and look at the nodule development; if you cut a nodule in half, you should see healthy pinkish color tissue in the center of the nodule.
“Soybeans often go through a period when leaves are light green or even pale yellow. This is the period just before the nodules start to supply adequate nitrogen to the leaves and is an important phase in the development of a healthy crop. Once the nodules have established and start providing nitrogen, the leaves will turn a dark-green colour. If proper nodulation, sufficient nutrients and moisture are present, soybeans will remain yellow for only 7-10 days” (Publication 811 Agronomy Guide).
Why do some fields look worse than others or even within the same field where there are different varieties? Different varieties display different characteristics. Varieties that are great emergers and are very vigorous will show these symptoms before a slower, weaker variety. There are even areas in the field that may have a little more compaction, especially from the heavy rainfalls last season. These areas are also showing these symptoms but may be showing them a little longer than loamy soils.
Be patient. Get caught up on your paperwork and weed control, and let Mother Nature take over. For more information on nodulation, click here. As always, if you have any questions, please contact your local Maizex Seed Specialist.
Chuck Belanger, Maizex Seeds Yield Specialist, North Essex and South Chatham-Kent Counties