“Where did my Bushels go?”
Have you ever had a harvest season where your first harvested wheat was the highest yielding and highest quality? Some say the bushels just diapered, why is that? This is essentially due to a loss in test weight. This is what is referred to as “Phantom Yield Loss”.
Wade Thomason, Extension Grains Specialist, Dept. of Crop & Soil Environmental Sciences, Virginia Tech conducted a study in 2001 and 2002 evaluating the effects of timely harvest compared to delaying harvest. The timely harvest moisture was 13.5% and the delayed harvest timing was 8 to 10 days later. Below is what he concluded from his study using two different cultivars.
There is a strong correlation between the number of rainfall events and loss in test weight. The more rainfall events equates to a higher loss in test weight. Wade found that on average, a 12 day delay in harvest resulted in a 6.4% reduction in test weight, going from an average of 58.8 lb/bu to 55.0 lb/bu.
The biggest influence on phantom yield loss is the number of wetting and drying cycles rather than the total amount of rainfall. However, large rainfall events do bring other concerns such as lodging and in more severe situations, possible hail damage causing head shelling.
How to manage Phantom Yield Loss:
- Have the harvest equipment tuned up and ready to go. (See Tims Article)
- Harvest early and harvest often!
- Consider harvesting at higher moisture (15-17%) and running it though a dryer. I know many like to take wheat off dry to avoid drying costs. However, the cost of lost test weight could be greater if left in the field through multiple rain events.
- The longer the wheat stays in the field the higher chance for reduced quality from increased toxin levels, sprouts, lodging, insects etc.
If anyone would like more information, please feel free to reach out to the Wheat Team.
Have a safe and happy harvest season!