WOW! We are having a lot of thunderstorms coming through our area in June. We have not been in the field for two weeks. Fields that got planted are waterlogged and all of the low areas have water ponding in them.
I want to discuss hail damage on soybeans because with these storms we got some areas with severe hail damage. First, the height and correct staging of the soybean plant is critical. Soybean staging is VE, VC, V1, V2, V3, and V (n) until you get to the reproductive stages.
VE is when the cotyledons have pulled through the soil surface.
VC is when the unifoliolate leaves have unfolds.
V1 is when the first trifoliolate leaves unfold.
V2 is when the second trifoliolate leaves unfold.
V3 is when the third trifoliolate leaves unfold.
Each vegetative stage has an axillary bud (growing point) at the joint where the petiole attaches to the main stem of the soybean plant. The main growing point of the soybean plant is the apical bud which is located on the top of the plant.
When a hail storm hits and cuts the soybean plants off below the cotyledons the plant is a total loss since there are no buds for regrowth. If the soybean plant is cut off above any of the trifoliolates or the unifoliolates the plant is still alive and will grow from the axillary buds, so the soybean plants will be shorter and have more branching. And if the apical bud is somehow severed or damaged, regrowth will come from the axillary buds.
There still will be a yield reduction of about 10% of optimum if the soybean population is reduced by 50% of optimum. If you have to replant by the end of June we are looking at an estimated 40% yield reduction due to late planting. If you incur hail damage don’t rush to the field to replant, wait several days to see how the plants respond. If the crop just emerged plant loss could be significant. But as the crop gets taller you may be surprised to see that fewer plants died than anticipated.
We are still getting storms in our area, I am not sure when we will get in the field to replant. We may just live with the lower soybean population and count on the soybean plant to branch out and fill in the blank areas where some plants are a total loss.