Soybeans and Frost
We are getting frost this week, it will probably catch some soybeans that are not yet physiologically mature. A green canopy is harder for frost to kill than a maturing canopy, because the green canopy holds heat better than a maturing canopy, and the green leaves have more solutes in the sap than a yellowing leaf. If the leaves get killed, but the petiole stays green, I'd expect the beans to suck most of the goodies out of the dead leaves anyway, with little net loss in yield from the frost. If the petioles are also killed , I'm not sure how much of the photosynthate in the leaves will make it to the seeds, but I suspect very little.
Frost injury will be pretty evident the morning after the frost. If only the top portion of the canopy get injured by frost, I'd expect the yield to be reduced only in the top portion of the canopy.
If the entire crop gets killed prematurely by frost, there may be little effect except smaller than hoped for seeds. Small seeds should be close enough to normal in content (e.g. oil and protein) that they will not get discounted at the elevator; green (in cross section, not just the seed coat) seeds probably will get discounted.
Frost injury will be pretty evident the morning after the frost. If only the top portion of the canopy get injured by frost, I'd expect the yield to be reduced only in the top portion of the canopy.
If the entire crop gets killed prematurely by frost, there may be little effect except smaller than hoped for seeds. Small seeds should be close enough to normal in content (e.g. oil and protein) that they will not get discounted at the elevator; green (in cross section, not just the seed coat) seeds probably will get discounted.
