Looking through the “periscope” of peanut production can be a tricky proposition, says University of Georgia Extension Agronomist Scott Tubbs, with growers needing to keep one eye on what’s going on around them and another on the future.
“You need to think ahead in planning your production practices so you don’t get stuck in a predicament. You want to look towards the future and also be aware of what’s going on now — what’s on the horizon, and also what’s to the right and left of you,” says Tubbs.
It can mean the difference, he adds, between continued high yields and superior quality — now being enjoyed by Georgia peanut producers — versus bad rotations, which have the potential to increase the incidence of pests.
“We’re talking in the broad term about pests, including diseases, insects, weeds and nematodes. Increasing your pest incidence will increase your input costs — not only your chemical inputs, but also the inputs required by things such as resistant weeds, which sometimes require both chemicals and hand labor,” says Tubbs.
The general recommendation for rotating peanuts is three years or more, he says, with four being the best bet. “You don’t want to be going back to the same land with peanuts any earlier than three years and preferably four years before you put peanuts back into the same rotation. Cotton and corn are your best rotational crops agronomically with peanuts,” he says.
Looking at peanut acreage in Georgia, in 2006, it was at 580,000 acres before it dropped in 2007, jumped back up in 2008, and resumed a more normal level in 2009, says Tubbs. Cotton was up to 1.4 million acres in 2006, dropping to 1 million in 2007, down to 940,000 in 2008, and back to 1 million in 2009.
Corn acreage in Georgia jumped dramatically to 510,000 acres in 2007, before dropping in 2008, and back to about 400,000 in 2009. Soybean acreage has climbed consecutively for the past four years in Georgia, he says.
“Peanuts and soybeans are both legume crops, while cotton and corn are not legume crops. This is what makes cotton and corn good rotations for peanuts. We want to go from a legume into a non-legume before going back into a legume crop. Peanuts and soybeans, both being legumes, have similar pest problems that can affect their production,” says Tubbs.
Peanut and soybean acreage combined increased from 2006 to 2007, increased again in 2008, and was hovering around 1 million acres in 2009. Cotton and corn combined went from about 1.7 million acres to about 1.4 million in the past three years, he says. The ratio of peanuts and soybeans, or legumes, versus non-legumes, is about .4 to .5, which means there is good potential there for a three-year rotation, says Tubbs.
“But whenever you get above .5, you run into rotational issues, and you have to go back in on land that already has been in peanuts in a recent time frame.”
Looking ahead, says Tubbs, it’s important that growers know what’s going on with their crop acreage. Rotational research has clearly shown the value of three and four-year peanut rotations, he says.
In Florida, he says, peanut acreage is typically 80 to 90 percent of the combined cotton and corn acreage. “In Florida, the ratio is extremely high, so it’s obviously not sustainable to get a three-year rotation going, and yields are suffering. A three-year rotation of cotton, corn and peanuts is impossible at these levels. Florida peanut yields are typically 6 percent to 10 percent less than Georgia yields.
“Growing conditions are not that different. They’re growing the same varieties, and I think much of the reason their yield is lower is because they have rotations that are not quite as good as they should be.”
In recent years in Georgia, says Tubbs, growers have been dealing with less cotton land and more soybean land. “You should not plant peanuts where you had soybeans last year and vice versa. There are too many issues that could suppress production in both cases. One of these could be CBR, which is caused by the same fungal organism in soybeans and peanuts. Red crown rot in soybeans is essentially CBR in peanuts. If you have CBR problems in your peanut fields, you don’t have a good control mechanism for taking it out of the equation. You need about five years out of peanuts or soybeans to get CBR under control.”
With soil-borne pathogens, you also need additional cleaning of equipment and even shoes as you move from one field to another in order to reduce the potential of the organism from spreading to other fields, he says. Georgia 02C and Georgia Greener are two good varietal choices if CBR is a potential problem in your fields, says Tubbs.
White mold also can affect peanuts and soybeans, he says. “You can put a lot of pressure on your cropping system and on your pesticide programs, causing you to need to spray more. And if you have resistant weeds out there, you don’t want pathogens to build resistance to fungicides.”
Nematodes on sandy soils also can be a threat, notes Tubbs. “We have new varieties that can help us with these issues but we don’t want to ignore rotations and depend mainly on varieties. We do have Georgia-07W with resistance to white mold and Tifguard is our only variety with resistance to nematodes.”
It’s important to know, he says, what is occurring or what has occurred in the fields you are planting. “If you rent land, and you’re farming a parcel that you’ve never farmed before, know the field history.”
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