Wheat PHS 5-1-24

Wet Harvest in the HRZ!

It’s no secret that it’s been wet. Wetter than usual, certainly for summertime. These high moisture and high humidity conditions have meant many growers have their headers parked up in the shed rather than out harvesting. South-West Victoria has only received roughly 2-3 weeks of harvestable weather despite starting two weeks earlier than usual, which was around mid-November. Not only do these conditions mean no harvesting, but it can impact grain in both harvestability and quality.

Pre harvesting sprouting (PHS) can occur when the grain in the head begins to sprout before harvest. The humid conditions and consistent rainfall that the Western Districts of Victoria have experienced these last few weeks put many growers at risk of PHS. While the conditions have been conducive, there are factors that can help provide some resistance to PHS. These include things such as drying rate of grain, level of grain dormancy at maturity, awn length, spike shape and head angle to name a few. Some of these factors are controlled by the plant’s genes and phenology. It is generally found that red wheats tend to have a reduced risk of PHS when compared to white wheats.

As PHS can impact grain quality, a test can be done at receival sites to determine if PHS has occurred. This test is called falling numbers test. Falling numbers will help to determine if PHS has occurred by identifying the sprouted grains. A falling number of less than 300 will result in grain quality being downgraded. A grower ideally wants a high falling number result, as a low falling number result means poorer quality grain. Newer varieties of wheats have been given a Falling Number Index (FNI) which gives an indication for the risk of having a low falling number. The higher the FNI rating the lower the risk of having a low falling number.

If you are considering retaining the crop for seed and you are unsure if PHS has occurred germination testing is a must, if PHS has occurred do not use for seed.

Trying to manage risk when it comes to PHS is important, but it is also hard when the weather can’t be controlled. Controlling things such as variety choice and timely harvesting can help reduce PHS risk. Having everything ready to go for when the conditions are suitable for harvesting will help reduce the crops exposure to more rainfall events by getting it off sooner.

As the weather continues to dominate decisions, using a decision matrix can help to think through the critical factors of which crop to harvest next or the considerations around using a grain dryer to harvest at higher moisture and then dry grain down.  You can access the Decision Wizard at https://sfs.org.au/tool/decision-wizard

For more information and resources on a wet grain harvest visit our blog https://sfs.org.au/blog/wet-harvest/

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