Richard Taylor, Extension Agronomist; rtaylor@udel.edu
With a weather forecast indicating the likelihood of several inches of rainfall over the next five to seven day period, the soil surface moisture levels will be recharged so that growers who halted their corn planting due to dry soil conditions will soon begin corn planting again. For full-season hybrids, yields begin to decline slowly at first as planting enters the May timeframe. Up until the middle of May, corn yield reduction for dryland corn averages around 8% but thereafter yield declines rapidly as the potential for unfavorable temperatures during the pollination period increase. Growers should try to have as much of their corn planted by the second week of May as possible to ensure the best chance for profitable corn production or switch to shorter season hybrids.
Research at the University of Delaware on dryland corn has shown that growers can switch to shorter season corn hybrids and loose ten percent or less of their yield potential when planting as late as May 26. Even an early June planting showed better yield potential (expressed as percent of maximum yield) for short-season hybrids. Hybrid selection will be a key factor since full-season hybrids often have higher absolute yield potential than the short-season hybrids. Also, select hybrids known to be “work horses” or those that can tolerate many stresses and still produce good yields.