For Noah, rain fell 40 days and nights. To some, life begins at 40. Others need 40 winks of sleep. For me, 40 is the number of days after planting in which Georgia peanut growers need to be finished with primary weed control.
The historical tendency for many growers is to make POST herbicide applications later rather than sooner. This often results in less-than-desirable weed control.
I cannot even begin to think how many times I have heard a grower say, “I wanted to wait until all the weeds were up before making an herbicide application!” As one famous conservative talk show host often says, “This makes blood shoot from my eyes!”
There are two very good reasons to consider my 40-day peanut weed control time limit:
- If you plan to be finished with your weed control program by 40 days, it is very likely you will have made your applications to smaller weeds. Smaller weeds are easier to control. It doesn’t get any simpler than that.
- If you are done before 40 days, you will not get forced into making a decision about using a POST herbicide later in the peanut plant’s life cycle. I have observed on more than one occasion certain herbicides applied around 60-75 days after planting (DAP) have the potential to cause peanut yield losses. This certainly does not happen all the time but it can happen, especially when it is hot and dry.
If you are a Doubting Thomas like me, seeing is believing. Check out the pictures of some of my peanut weed control plots from 2015. Take special note of the fact that my EPOST or “at-cracking” herbicide applications were made at 17 DAP while POST applications occurred at 36 DAP. Plot photos were taken at 100 DAP. The weed control illustrated in these pics lasted until harvest.
For the record, my 40-day time limit does not include rescue applications of 2,4-DB, which is frequently used late-season in peanuts to slow down the growth of weeds such as sicklepod and annual morningglory. In general, peanut tolerance to 2,4-DB is outstanding.
It is very easy for me to say that you should be finished with your primary peanut weed control program by 40 DAP. I do not have to drive over 500 or 5,000 acres of peanuts. I fully realize that good intentions are often foiled by bad weather or other extenuating circumstances such as equipment breakdowns, employee malfunctions or NetFlix binge watching. All I can do is encourage you to do the best that you can to try and stay around that 40 DAP time-frame.
As always, good weed hunting!