Floodwater from the Mississippi river and other drainages threaten to destroy many acres of wheat which are ripening and approaching harvest. Many are wondering if there are any methods to hasten wheat maturity or permit harvest before floodwater destroys the crop. Although many initially consider spraying wheat with a herbicide or desiccant prematurely, I don’t believe this option offers much viability. Killing the crop before it reaches the hard dough stage, when kernels are physiologically mature, will cause kernels to abort grain filling prematurely, reducing weight and cause kernels to shrivel. This will reduce grain quality where it may severely limit marketability and of course yield potential, depending upon crop maturity. Thus, this is why the appropriate timing to use a harvest aid or any practice designed to enhance harvest is the hard dough stage or thereafter.
The critical hard dough stage can be readily identified by the transition of kernels from green to brown color and the stem or peduncle immediately below the head turning from green to yellow. Since the wheat plants are naturally senescing or dying at this age, a harvest aid is not going to do much to promote quicker grain drydown, unless younger plants are killed prematurely. At the hard dough stage, wheat kernel moisture will be approximately 30-35%. After this time, grain drying rate may be as high as 2% per day, depending upon high temperature and low humidity. Therefore, the most practical option to hurry wheat harvest may be to initiate harvest of high moisture grain, particularly if you have grain drying equipment, rather than waiting for it to field dry to the standard of 14% or lower moisture. I would suggest cutting combine wheat samples soon after hard dough stage to monitor moisture and maturity of grain.