Cool Temperatures, Pod Maturity and Digging Peanut Notes No. 217 2020
The projected cooling of temperatures this coming week will increase the anxiety of deciding when to dig peanuts this fall. Our rule of thumb is that when temperatures are in the high 40s for two mornings in a row, progression in maturity essentially stops or slows to a snail’s pace. However, it is only September 20 and many of the peanuts planted in May are just now approaching optimum maturity. There is time for temperatures to warm back up. Some peanuts planted in May experienced drought and did not set pegs until early August. The same is true for peanuts planted in June, especially mid and late June. These peanuts need more time and might not be at optimum maturity until late October (even without the lower temperatures we will experience during the week of September 21).
With all of that said, here are my thoughts:
Best case scenario: After cool temperatures during the week of September 21, temperatures moderate and pods progress in maturity during the week of September 28. If there are no storms projected, growers can leave peanuts in the field for that week and peanuts will likely progress in maturity (moving from yellow to rust/orange or rust/orange to brown makes a huge difference in yield and quality.) If temperatures remain relative mild after warming during the week of September 28, and if temperatures during the week of October 5 moderate and no storms projected, it is possible to let the peanuts stay longer and see how they progress in maturity. I know this takes a lot of patience! We are projecting well into October now.
Worst case scenario: Cool temperatures persist for the next two weeks and pod maturity does not increase. Unless we have a really warm October, there is likely little value in leaving peanuts in the field. This decision might be made at the end of the coming week (about September 25) relative to projection for the week of September 28. But with many fields with very few mature pods, we need to give this crop some time.
The wild card in all of this is rain and tropical weather. If maturity does not advance any this week and it looks like we have a lot of rain headed our way, we simply may need to dig a less-than-mature crop. I hope that is not the case.
This is a “historically typical fall” for North Carolina in that we have experienced a cooling trend in late September. The past three years have not been typical in that sense with September and part of October feeling more like early September.
As we try to let peanuts get as mature as possible we take some risk in doing so (A typical David Jordan understatement that points out the obvious.) If you can find an extra digger and a person to operate it, this might be a good year to make that investment. This is a better option than digging at excessive ground speeds. For example, a KMC digger needs to be in the 2 to 2.5 MPH range. When we approach 3 MPH we are losing peanuts.