Pre-harvest sprouting (viviparous germination) in lodged wheat, Triticum aestivum. The picture shows ripe ears of a wheat plant on the ground following a period of rain that delayed harvesting and flattened the stems of the plant ("lodging"). Many grains - the seeds of the plant - have germinated within the ears to produce green shoots and white roots.Pre-harvest sprouting is a hazard of many modern varieties of white wheats; it is less common in red wheats. It results in economic losses to the grower due to smaller yields and poorer quality. It is caused by weak physiological dormancy in the seeds, which consequently can be broken by adverse weather conditions around the time of harvest; periods of continuous heavy rain leach out the natural inhibitors of germination, particularly the hormone abscissic acid (ABA)