Climate instability: Rainfall on pre-harvest wheat, sprouting or nothing?

Untimely, pre-harvest rainfall (PHR) on wheat has become more frequent during the current period of climate instability. It is unclear whether these rain events can affect grain quality and subsequent marketability. The objectives of the research are: 1) Developing a simple and quick diagnostic tool to identify grains that have absorbed water and have subsequently dried up; 2) Identifying changes in PHR grains that have absorbed water. Wetting with either sprinklers or micro-sprinklers caused the grains to swell and soften but not to crack, and certainly not to germinate or sprout. Two diagnostic methods were developed: 1) Based on NIR and Multiplex scanning; 2) Based on the ratio between test weight (TW) and thousand kernel weight (TKW). Wetting caused a significant reduction in TW, dough elasticity and dough water absorption, and an increase in Falling Number (FN), flour particle size, and dough strength. Under Mediterranean climate, there is no major PHR effect on grain quality. Moreover, FN could not be used to determine that grains had undergone wetting. However, the reduction in TW due to wetting reduces the farmer's income. Our results emphasize the need to change the method of pricing wheat in regular marketing due to PHR rains. • Pricing wheat in regular marketing due to pre-harvest rainfall should be changed. • Falling Number could not be used to determine seeds had undergone wetting. • Pre-harvest rainfall caused a significant reduction in test weight. • Adding autofluorescence data to NIR improve differentiating dry/wetted grains. • There is no major effect on grain and flour quality regarding pre-harvest rainfall.