Falling Number As A Measure Of Pre-Harvest Sprouting: What Does It mean? (Jul 17, 2013)

By Pierce Paul

As was explained in last week’s newsletter article, delayed harvest in association with repeated wetting of the wheat heads often leads to pre-harvest sprouting. This is characterized by the swelling of kernels, splitting of seed coats, and germination of seeds (emergence of roots and shoots) within the wheat heads. Once wheat starts to sprout (or even before it actually sprouts), enzymes are produced to break down sugars that provide the energy needed for sprouting (germination). Burning us these sugars while the grain is still in the head reduces the milling and baking quality of the flour produced from this grain, since the emerging plant ends up using up much of what is needed to produce good quality flour. This leads to down-grading or even rejection of the grain.

Falling Number provides an indirect measure of the activity of the enzymes responsible for breaking down the sugar during sprouting. Consequently, it provides a measure of sprouting and grain quality. Remember, the greater the activity of these enzymes, the worse will likely be the quality of the grain. Falling Number is reported in seconds (click on the link below for details). As enzyme activity increases, the Falling Number decreases, therefore a Falling Number of 350 seconds or greater indicates low enzyme activity and good wheat quality (low sprouting). On the other hand, values below 200 seconds are usually associated with severe sprouting and low grain quality. For more information on the actual test used to measure the Falling Number, please refer to the article below published by the University of Delaware.