Despite hope, the soybean crop may not fulfill expectations
But what if a good rain occurs, will the soybean plant recover and begin its reproductive process? Nafziger says rain may result in new flowering at the higher parts of the soybean plant, but with the lack of a full canopy, the plant’s ability to produce sugar and fill any pods will be severely limited. The photosynthesis process, which produces sugar, has been restricted by the shortage of moisture and soybean leaves that have turned over to conserve moisture, as well as the lack of a full canopy to capture the maximum amount of light.
Any double-soybeans that would have been planted later in the growing season have even a shorter plant height, and subsequently fewer nodes, flowers, and pods. Nafziger says if better moisture conditions arrive, the later planted beans may have opportunities to recover with more flowering and pod-forming ability. But he says the shorter height and lack of canopy will restrict the ability of double-crop beans to produce the sugars needed to fill pods.
But what if you can relieve any other stress on the crop, such as fungal or insect issues, would that help? Nafziger says any other inputs, such as fungicides or insecticides will have little ability to help the soybean crop with its overwhelming lack of moisture. He says it is still important to scout for pests, but any additives will have little ability to save the crop which is in such severe moisture stress.
The soybean plant is suffering from severe moisture stress and subsequently internodes are short, blooms are not producing pods, and the lack of a canopy will restrict the ability of the plant to produce sufficient sugars to fill pods. Any relief from the drought will allow the top of the plant to bloom and form pods, but the lack of a canopy will restrict yield as it will in shorter double-crop soybeans.
Source: FarmGate blog