Peanut Maturity

We’re getting closer to looking at peanuts to check maturity. I checked my first sample yesterday. We were really just wanting to see how far away we were to make decisions on last fungicides. Peanuts looked further along than expected.

PeanutMaturitySample-PlantedApril27 002

These 06G’s were planted April 27th and 28th, and show a maturity between 14 and  days away. We didn’t have a perfect representative sample, so this may affect it. Peanuts mature based on temperature and available moisture. With high temperatures since June, questions have been about crops maturing early. UGA Agronomist Dr. Scott Monfort says this won’t necessarily affect everything the same. For instance, our early April planted peanuts (in cooler temperature) will stall, then later April planted peanuts will mature faster. Every field situation is going to be different, so sampling is the best way to really know.

In this sample, I was finding a lot ‘turning loose’ in the hull. We need to remember to crack open the pods to observe the funiculous. This is the umbilical cord that connects the kernel to the pod. Once it turns loose, the next rain can make them sprout.

Sometimes it’s hard to see the ‘umbilical cord’ before you break it yourself. Another way to make this observation is just look at the kernel. If the kernel is white with few oil spots, it’s still feeding. If the kernel is dark and shriveled, it has turned loose. I took a picture of these two. They are not always this easy to tell, but looking at them this way has helped me. I start on the right side (mature pods) and work my way back. I cracked 35 pods in this same and 6 were turned loose. 17% is pretty significant.

Top peanut still feeding; bottom peanut turned loose in the hull

Top peanut still feeding; bottom peanut turned loose in the hull

Sampling Procedure

Growers, make sure you have a good representative sample. Get plants from at least 3 spots in the field. Also, don’t just pick off the larger pods. We really need to pick off small pods as well. If we pick off large pods, it can bias the sample toward digging early. There is enough data to show that we lose as much as yield if we dig a week early than a week late. If we dig a week late, there is no difference. We don’t see difference again until we dig 2 weeks too late. We still have to consider the condition of the vines. Definitely look at the vines well as you pull off pods. Also, 180 – 200 pods is good for a sample.

Prevent Digging Losses

Miller County Ag Agent, Brock Ward was talking with me about losses just from the digger. He went back and found good information from former UGA Agronomist Dr. John Beasley on digging losses that I think is good to share:

You can do everything just right during the season to maximize yield and grade potential but blow it all at harvest.  It is very easy to lose several hundred pounds per acre in yield by not being careful when digging. Growers need to take their time and set the digger-shaker up properly and then run at the proper ground speed to maximize digging and inverting efficiency.

In 1990, Dr. Mike Bader and I conducted a digging efficiency trial at the Sunbelt Expo Farm. We had a replicated trial in which we dug as close to perfect as possible, too fast, too slow, too shallow, and too far left or right. We took an area the width of the planted bed (6 feet) by 3 feet in length from each plot within the trial and collected pods on the soil surface and from the top three inches of the soil. We threw out the obviously diseased or non-harvestable pods, and weighed the harvestable pods that would have yielded and graded.

Even where we dug as close to perfect as possible we calculated losing approximately 120 pounds per acre. We know that producers do not harvest too shallow on purpose, but if they are not paying attention the digger blades can ride up more shallow if the soil is too hard. We measured pod yield losses in the range of 1,000-1,200 pounds per acre in the too shallow, too far left or right, and the too fast treatments.

Bottom line is that digging losses can take a significant chunk of yield potential. Another critical factor is to make sure they are using sharp digger blades. A set of digger blades is usually good for a limited number of acres, depending on soil type. On the heavier soils 15-20 acres may be the limit on a set of digger blades so check them often to make sure they are wearing evenly.  Growers need to be very careful at digging to reduce harvest losses.

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