If you're growing peanuts for the first time this year, the most important decision you might make is from whom you'll be taking advice.
“There are a lot of people giving it out,” says Dallas Hartzog, Auburn University Extension agronomist. “But this is your money. Your job is to evaluate from whom you'll be taking advice. If you know of someone who's already producing peanuts, it'll be worth your time to go and see that person. The guy who is putting it on the ground is invaluable to you.”
If you're growing peanuts where they haven't been grown before, you'll need to inoculate, says Hartzog. “You must use live bacteria. I can't tell you how many times I've been out into a field, and the grower had bacteria sitting in the sun. In May, when it's about 85 degrees outside, that bacteria will be dead pretty soon. If they are live bacteria, you must remember to keep them alive,” he says.
Hartzog recommends buying peanut inoculant from someone who does a large volume of business. “Don't buy inoculant from the guy who says he has had only one box shipped to him. You want fresh bacteria,” he says.
Growers can use a dry or liquid product, he adds, but a hopper box material generally isn't as effective as that sprayed on the seed.
“You need to put it directly on the seed. If you're planting, and weather conditions are dry, live bacteria will die in dry soil.”
Peanuts are a legume, says Hartzog, and if you're planting cotton, there isn't a need for using peanut phosphorus fertilizer. “It won't make you another nut. You can't show me a scientific publication that shows an increase in yields due to adding phosphorus fertilizer,” he says.
Most cotton producers already are using potassium, and there's no need in “piling it higher and deeper,” says the agronomist. “Take a soil sample. Peanuts respond to soils with potassium levels less than 40 pounds. The Auburn University soil test recommendations are based on 463 on-farm experiments conducted from 1967 to 1995. That data, along with data from Georgia and Florida, make up the universities' soil testing recommendations, and they're all the same.”
Lime, says Hartzog, is ground-up rock, and it has be mixed with acid soil to be effective. It can supply calcium and magnesium if you mix it with the soil, he says.
“If you're strip-tilling, and you put lime on top of the ground, it won't be very effective. If you rely on calcium from limestone, that calcium will stay put in the pegging zone. If you put out gypsum, and it rains, it will slowly but surely leach out.”
The sandier your soil, the more likely it is that you'll have to use gypsum, says Hartzog. “If you take a soil test, you can tell with 100-percent certainty which fields need it, and which ones don't need it. We recommend lime if the soil pH is less than 5.8. We like to see it up around 6.3 to 6.5.
“A calcium deficiency will put you out of business. It causes peanuts to be poorly developed, which results in poor grades and yields. You get paid on yields and grades, so you need to stay in a good liming program, and you need to have your calcium value high in the pegging zone.”
Peanuts, says Hartzog, are a unique crop in that they have an above-ground flower and a below-ground fruit. Peanuts have the ability to take up calcium in the root system and place it in the leaves. “Due to the water pressure gradient, they cannot take that calcium and put it in that developing peg that is underground.”
Not many fields will need gypsum, and it's an added expense of $30 to $35 per acre, he says.
Peanut growers also should pay attention to minor elements, such as boron and manganese, says Hartzog. “If you soil test and keep your pH between 6.0 and 6.5, you won't have a problem with a manganese deficiency. If you do have this problem, it's difficult to correct. If the pH goes beyond 6.8, manganese will be taken out of the soil solution, and deficiency symptoms will occur.”
Most peanut producers who also grow cotton already are using boron, he says. “You won't see much of a response to boron behind cotton that has been fertilized with boron. Peanuts have a deep root system, and the boron hasn't been completely used by the cotton crop.”
A boron deficiency in peanuts is called “hollow heart,” says Hartzog. The kernel half is caved in and discolored, and it affects peanut quality, he says.
“It's a form of concealed damage found when you grade the peanuts. If enough is present, it lowers the grade. You can prevent the problem by putting out three tenths or one half pound of boron in the row or 1 pound broadcast.“
It's best, says Hartzog, if peanut growers plan not to cultivate their crop. “You cultivate only to control those grasses and weeds you can't control otherwise. Cultivation might put soil on top of the peanut limbs, and that's where your fruiting structure begins. If you cover it up, you instantly reduce your yields.”
Long-term research, he says, has shown similar yields between strip-till and conventional peanuts. The average of 48 plots from Georgia, Florida and Alabama showed that conventional peanuts made 6,000 pounds per acre while strip-till made 5,700 pounds per acre.
“Many farmers strip-till peanuts successfully. Peanuts really don't care how you loosen the soil. Peanuts want a weed-free environment and a stand that comes up uniformly and quickly, with good disease control. But as it affects the other parameters, it's very important how those peanuts are planted. If you put a stand of peanuts in lumpy, cloddy, trash-covered ground, and they come up at different times, tomato spotted wilt virus will get you.”
Research from 48 plots also compares twin-row peanuts and single-row peanuts, says Hartzog. Twin rows were planted 7 inches apart, three seed per foot. Single rows were 36 inches with six seed per foot.
Twin-row peanuts made 6,140 pounds per acre while the single rows made 5,570 pounds per acre. The relative difference in the two row patterns is almost the same in each year of the research, says Hartzog. “We may be approaching 50-percent twin rows in Alabama. A lot of growers in non-traditional areas plant in twin rows.”
During harvest time, peanut growers will learn, he says, that they can fill a trailer quickly. “Your success as a peanut farmer might be tied to how successful you are in getting those peanuts away from your farm on a semi-truck. Your relationship with the truck dispatcher will be very important.
“When Hurricane Ivan came through Alabama last year, everyone began digging and harvesting at the same time. The truck drivers began hauling hurricane debris at twice the salary, and it put a bottleneck in peanut harvesting.”
Harvest capacity has increased markedly in recent years, he says. “We have a lot of acreage, and the ability to harvest it in a hurry has changed the peanut industry.”