We are scheduled to have lows in the 40s this weekend. Our rule of thumb is that when we get below 50 F for 2 mornings in a row peanut maturation essentially stops unless we get a 3 week warming trend. I'll post weather data from several locations by Monday. It looks like we are going to have only one day in the 40s and then warm up significantly to a low in the mid-50s. Of course one night with lows in the 40s will slow peanuts down but not like it would with two days or more at those temperatures. I discuss this on pages 38 through 43 in 2022 Peanut Information. Maturity did not increase from September 17 to October 15 at Lewiston in 2019. In Figure 3-5, you can see that we had temperatures at the threshold I mentioned above to stop maturation around September 23, October 3 and October 15. Peanut never had a chance to progress that year because of the 3 (2-day cool temperature) events. With only one day this year we might be able to make more progress. But the 10-day outlook is for cool temperatures during the middle of next week in some of the northern areas.
The dry weather and the already slow movement toward maturation will be compounded by the cool snap. With that said, rainfall looks to be rare in the coming weeks, so those with patience can go from week to week and possibly pick up more weight and grades. But I fully understand that some folks are already ready to start digging next week and move through the crop without delay.
I don't see a threat from frost right now but we will post information on that as that threat becomes more apparent. In short, you need 72 hours between digging and frost (under good drying conditions) to avoid freeze damage.
After this week I would not apply any more fungicides for leaf spot control. We are well past the window for any Sclerotinia blight sprays (effectiveness or PHI). Benefits of sprays for mites is quite low due to the fact that injury is already in place and cooler temperatures will slow the mites down significantly.
If you're unsure on digging and would like peanuts checked, contact Dylan Lilley at 252-333-6601.
