Expected Cold Snap To Shut Down Georgia Peanut Growing Season
By: John Beasley, UGA Extension Peanut Agronomist
10/24/2013 12:18:38 PM
The National Weather Service forecasts low temperatures over the next three to five days, dipping into the lower 40s and upper 30s. The coldest nights are expected this weekend. This cold snap likely will shut down peanut maturity in Georgia.
When we have three or more days with low temperatures in the lower 40s or lower, the peanut maturation process will shut down. With the forecast for the next 3-5 days indicating low temperatures in that range, we would not expect any fields to mature beyond where they will be as of this weekend.
Even if a Hull-Scrape Maturity Profile indicates a field is 7 days, 10, days, etc. from reaching optimal maturity, the maturation process will shut down as soon as we have the kind of temperatures we expect to get over the weekend. Growers who have fields left to be harvested, make plans to begin harvest as soon as the colder mornings pass.
A more critical point: DO NOT DIG the day before a morning in which the low temperature is low enough that there is a risk of frost or freezing. The low for this coming Friday night / Saturday morning is 38 degrees in the Tifton area (possibly colder in your county). Once we start approaching the 35-36 degree range, frost can occur, especially in low lying areas of a field where the colder air will be.
Keep in mind, the recorded low temperature is measured at 5 feet above ground by the NWS. Cold air sinks, which means it could be a few degrees colder in low-lying areas of fields.
Frost or freezing temperatures on freshly dug peanuts can cause freeze damage to the kernels, which in turn, can be graded as Seg 2 peanuts. Seg 2 peanuts are greatly devalued when graded ($132 per ton). If a field is dug on Friday afternoon and we approach the middle 30s the next morning, freeze damage can occur.
When dug, peanuts have 40 percent or greater moisture. Two or three days in the dug windrow allows the moisture content to drop enough so that the seed separates from the inside of the hull. This separation will alleviate the risk of freeze damage. High moisture content with a seed still in contact with the inside of the hull increases the risk of freeze damage.
Once we get past Saturday morning the forecast is showing warmer low temperatures as we enter next week.
With the forecast of the low temperatures in the lower 40s and upper 30s for several days, it looks as if we can call the 2013 peanut season over. We might as well harvest what is left since we would expect very little, if any, advancement in maturity with the colder temperatures.
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