From an Ohio Guide Lowell Knehans 07/03/2012 @ 7:42pm From the two weeks before through the two weeks following pollination, corn is very sensitive to drought, however, and dry soils during this period may cause serious yield losses. Most of these losses result from pollination failure, and the most common cause is the failure of silks to emerge from the end of the ear. When this happens, the silks do not receive pollen; thus, the kernels are not fertilized and will not develop. Drought later in grainfill has a less serious effect on yield, though root function may decrease and kernels may abort or not fill completely. Table 4-2: Effects of Drought on Corn Yield During Several Stages of Growth.* Stage of Development Percent Yield Reduction Early vegetative 5 to 10 Tassel emergence 10 to 25 Silk emergence, pollen shedding 40 to 50 Blister 30 to 40 Dough 20 to 30 * After four consecutive days of visible leaf wilting. Source: Claassen, M. M., and R. H. Shaw. 1970. Water deficit effects on corn. II. Grain components. Agron. J. 62:652-655.