Pre-Harvest Sprouting Of Wheat

Jul 10, 2017

By Martin Nagelkirk

Grain may be subject to pre-harvest sprouting once wheat matures. Indicators of maturity include browning of the stem immediately below the head (stem on right).

As wheat matures in central Michigan, minimize the risk of sprouting (low falling numbers) as some early grain loads suggest some fields are testing moderately low.

Pre-harvest sprouting of wheat is always a potential risk, but this season there is some concern given the past and current weather pattern and some early test sample results. In any event, here are a few reminders regarding the issue.

Pre-harvest sprouting sometimes occurs when natural dormancy is broken, triggering the kernel to behave as a germinating seed rather than a starch-storing grain. This process begins well before there is any visual evidence of sprouting. This is why for decades the milling industry has relied on a Falling Number test.

The Falling Number test score is actually the number of seconds it takes a plunger to fall through a grain/water slurry under very controlled conditions. The industry generally prefers grain measuring 300 seconds. Depending on the end-user, there is often significant concern when the seconds slip below 250 or 275.

Pre-harvest sprouting is more likely when grain is exposed to moisture in the form of rain, fog or high relative humidity. While the process may be more likely to begin at lower grain moisture levels, it’s clear that the process can occur as soon as grain reaches physiological maturity (35 to 40 percent).

There are differences in susceptibility among varieties. Soft white and many soft red wheat varieties grown in Michigan are considered susceptible or moderately susceptible. Linda Brown, PhD candidate at Michigan State Univeristy, has categorized many of Michigan’s commonly grown varieties relative to sprouting in “Wheat Variety Comments, 2017,” page 2 in the sprout column.

This grain sample tested 40 percent moisture (at or near maturity). Note the range of kernel development. A few kernels from the same head or adjacent heads were still slightly green and some retained inner husk.

MSU Extension recommends the following:

Bring samples to your local elevator before or as soon as harvest begins to learn if grain has a marginal falling number score.
Harvest as soon as wheat can be reasonably threshed, especially where grain has marginal falling number scores and the variety is not resistant to sprouting.
Be prepared to segregate grain from different parts of the same field as there can be significant differences in falling number.
Never blend grain having low falling numbers with good grain. Blending low with high falling number grain is not additive. For example, if you were to blend grain having a falling number of 150 with an equal amount of grain having a 250 score, the bulk load will not test 200; rather, its score will be closer to the 150 second level.

Source: msu.edu

Video: Spring 2026 weather outlook for Wisconsin; What an early-arriving El Niño could mean

Northeast Wisconsin is a small corner of the world, but our weather is still affected by what happens across the globe.

That includes in the equatorial Pacific, where changes between El Niño and La Niña play a role in the weather here -- and boy, have there been some abrupt changes as of late.

El Niño and La Niña are the two phases of what is collectively known as the El Niño Southern Oscillation, or ENSO for short. These are the swings back and forth from unusually warm to unusually cold sea surface temperatures in the Pacific Ocean along the equator.

Since this past September, we have been in a weak La Niña, which means water temperatures near the Eastern Pacific equator have been cooler than usual. That's where we're at right now.

Even last fall, the long-term outlook suggested a return to neutral conditions by spring and potentially El Niño conditions by summer.

But there are some signs this may be happening faster than usual, which could accelerate the onset of El Niño.

Over the last few weeks, unusually strong bursts of westerly winds farther west in the Pacific -- where sea surface temperatures are warmer than average -- have been observed. There is a chance that this could accelerate the warming of those eastern Pacific waters and potentially push us into El Niño sooner than usual.

If we do enter El Nino by spring -- which we'll define as the period of March, April and May -- there are some long-term correlations with our weather here in Northeast Wisconsin.

Looking at a map of anomalously warm weather, most of the upper Great Lakes doesn't show a strong correlation, but in general, the northern tiers of the United States do tend to lean to that direction.

The stronger correlation is with precipitation. El Niño conditions in spring have historically come with a higher risk of very dry weather over that time frame, so this will definitely be a transition we'll have to watch closely as we move out of winter.