Pod Blasting Peanuts
I grew up in southeastern Virginia where peanuts and cotton were, and still are, the major crops farmers grew. It wasn’t cooler temperatures or shorter days that signaled fall, but peanuts being dug and cotton bolls dotting the landscape like snow.
When I started working with North Carolina Cooperative Extension, the only thing I knew about peanuts was that they were dug in the fall and the vines could be baled for cattle feed. The field crops agent invited me to help him pod blast peanuts and it was there I learned how farmers decide when to dig. Unlike many crops, peanuts grow underground, so you can’t just ride by the field and tell when they are mature. The color of the pod is key.
The pod is the shell of the peanut and, as it matures, the color of the inner hull changes from white to yellow, orange, brown, and finally, black. Peanuts start flowering when the plant is 40 days old and continue until harvest, so it is always producing new peanuts. They are one of the few plants that flower above the ground but produce fruit below the ground.
The goal of pod blasting is to determine the optimal harvest date, so peanuts are turned over at the best time. If dug too early, farmers can lose a significant portion of the crop. If dug too late, mature pods will fall off the vine and not be harvested. Unlike produce such as strawberries and apples that can be harvested throughout a season, a peanut field is dug at one time, so the decision to dig is an important one.
Farmers used to collect samples and scrape the pods with a knife. Pod blasting speeds up the process and can give the farmer a picture of the field in minutes.
Getting an accurate maturity prediction starts with the sample. Like soil sampling, farmers pull plants from different spots in the field. The first samples are pulled when plants are 100 to 120 days old. All peanuts are picked off the plants until there are at least 150 to 200 in the bucket.
The peanuts are put into a wire basket and a lightweight pressure washer is used to remove the outer layer of the pod (or hull) to reveal the color underneath. During this step you must be careful not to destroy the peanuts.
Now comes the big reveal. The bucket is dumped on a maturity board and peanuts are sorted by color. This gives farmers a picture the average maturity of peanuts in the field. If most of the peanuts are yellow, they need another 10 to 14 days to mature. In this case, the farmer may check another sample the following week. If most pods are brown, the farmer is probably going home to get the digger hooked to the tractor.
Other factors like weather, vine health, and number of acres planted in peanuts will play into the final decision. Seeing the pods sorted on the maturity board paints a picture that makes the decision of when to dig much easier for the farmer to make.