How a wet fall impacts grain quality
How a wet fall impacts grain quality
Cool, wet conditions in the fall pose many challenges. Besides delayed harvest, grain quality is another major concern. When exposed to moisture such as rain and heavy dew, mature grains may experience pre-harvest sprouting (PHS) and fungal infection, both of which reduce grain quality.
Pre-harvest sprouting
Pre-harvest sprouting is the sprouting of mature cereal grains when grains are still on the heads or in the swath. During sprouting, the seed breaks dormancy, activates enzymes that converts starch into sugar. As a result, the baking quality of the grain is reduced. The sprouted grain may not show any visual damage; however, falling number measurement indicates PHS damage in wheat.
Besides PHS, repeated wetting and drying also reduce the test weight of grains, another key factor in grain grading.
Fungal growth
Fungal or mould growth is another concern when harvest is delayed by wet conditions. Fusarium species produce various mycotoxins, such as deoxynivalenol (DON) and zearalenone (ZEA) in infected grains. They pose health risks to consumers and reduce grain grades. In addition, when grains are stored above safe moisture levels, ochratoxin A (OTA) can develop in the stored grains and impact marketability.
How to manage these quality issues?
We cannot control weather conditions; however, there are a few things that help mitigate the risks
- Separate the grains from different fields/areas. Each field may have different varieties, experience different levels of wet conditions, or in some cases, the low-lying area of the fields are more prone to grain quality loss. In this case, separating the grains from the most impacted area may be a wise first step to avoid contaminating the whole bin.
- Dry the grain. Start drying the grain immediately after it is harvested from the field. Do not let it sit in a truck or bin without aeration. Dry the grain to safe storage moisture with the best available resources and facilities.
- Test the grain. Knowing what you are dealing with is the first step in finding the solution and the right market. Send the grains to an accredited lab to test for the key quality parameters impacted by a wet fall.
Additional resources:
Chit Happens: Understanding Pre-Harvest Sprouting Challenges and Future Solutions