Reports of low Hagberg Falling Numbers (HFN) in this year's HRSW crop are coming in from the Crookston to Mahnomen area. This is the same area were growers noticed problems first last year. I wrote a blog post last year that details a lot of the technical details of the HFN test and why it matters to buyers. You can find that post here.
We also learned some things from last season. First, the number of rain events i.e. repeated wetting and drying cycles matters to trigger preharvest sprouting. No discernable differences in HFN were found between varieties with a Preharvest Sprouting (PHS) tolerance rating of 1 and 2 and varieties with PHS tolerance of 3 or worse when less than 4 rain events were recorded between physiological maturity and grain harvest. It took actually 12 wetting events to start seeing the first sprout damage and a corresponding drop in HFN in the varieties with poorer PHS tolerance. Secondly, we had no indications that Late Maturity Alpha-amylase (LMA) played a role in the occurrence of low HFN scores.
I'm a bit surprised by reports coming in because we have had fewer than 5 rains events since the spring wheat crop reached physiological maturity in the last days of July and the first few days of August for a majority of the fields in this region.
Regardless, as we go forward with the harvest, you can deploy two tactics to preserve the quality of the crop that left out there; to maintain HFN numbers you're better off to harvest the grain at 18% and use a grain dryer to bring it down to 13.5% grain moisture rather than risking another wetting event. And you are better off harvesting the fields that reached physiological maturity last first once you suspect problems with sprout damage in those fields that were ready to cut earlier. The idea is that these fields received fewer rain showers since reaching physiological maturity and thus have a greater probability not to have sprouted yet.
Is there anything to putting it in the bin?Seems like last year guys getting killed at harvest had numbers go up after a few months in the bin.
ReplyDeleteTim - Apart from the variability that result from sampling and the variability that results from not properly conducting the Hagberg Falling Numbers test, the HFN should eventually go up when the grain is stored. The reason it will go up is quite simple; the alpha amylase that was activated as a consequence of the sprouting will degrade over time and no longer be functional. Unfortunately, the associate starch damage does not reverse and so the end-use quality still is affected. Likewise, the viability of the grain is also irreversibly damaged and germination will be poor.
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