Research Review

The Goal: Profitable Peanut Production

From above ground to below and high overhead, peanuts are the fascination of researchers across the United States. Thanks to farmers who help fund many of these projects through the National Peanut Board, scientists explore all areas of peanut production. In fact, since 2001 the National Peanut Board has invested more than $37 million in production research.

Every year, 60 to 80 projects are selected for funding. These studies explore every facet of the peanut. From the molecular level to the field view and from specific problems to integrated approaches, the goal of these research efforts is all the same: more sustainable and profitable peanut production for the farmer.

FROM SPECIFIC TO INTEGRATED

Weed seed want to grow and thrive as much as peanut seed. The competition created for sunlight, water and nutrients causes economic losses in the peanut crop. Farmers spend money and time trying to combat weeds. Successful weed management requires cultivation and/or multiple, timely, effective herbicide applications.

As hearty and sustaining as they are when eaten, peanuts do not compete well with weeds. That’s why farmers are advised to keep peanuts weed free for the first 45 days after planting and newly emerged weeds knocked back until the crop achieves canopy closure. Once established, competition is not so much the problem as is interference with pesticide applications and harvest equipment, which reduces equipment efficiency and causes yield loss.

Weeds are a topic for peanut researchers, and projects can be specific to one weed or as broad as weed management

overall. For instance, yellow nutsedge is one of the most problematic weeds around the world.

University of Georgia weed scientist Tim Grey studied yellow nutsedge control in peanut. Specifically, Grey’s objective was to determine if diclosulam, which is an effective herbicide against many weed species with activity on nutsedge, was effective on yellow nutsedge tuber production.

Through his research, Grey found that diclosulam is an effective herbicide that controls yellow nutsedge foliage and also reduces the number of tubers produced. It also reduces tuber viability.

Peanut weed management trials are an expansive set of study plots looking at peanut with a list of herbicides. The outcome of these trials resembles what farmers often face in the field. Todd Baughman, Oklahoma State University Extension weed scientist, conducted a weed management trial, and his study resulted in the following information:

“Texas panicum, Palmer amaranth and ivyleaf morningglory control initially was at least 90% with Prowl H2O preemergence. Chloroacetamide herbicide (Outlook, Warrant or Zidua) helped extend control. While early season control was excellent, Cadre + 2,4-DB postemergence was needed for season-long control of Texas panicum and ivyleaf morningglory. Early season yellow nutsedge control was less than 85% with all treatments. The only treatments that controlled Palmer amaranth at least 95% and yellow nutsedge at least 90% late season were Prowl H2O preemergence followed by Zidua + Gramoxone at cracking followed by Cadre + 2,4-DB alone or with Outlook postemergence.”

From a specific problem to overall field management, researchers are helping producers tackle problems and maximize yield.

Weed research may focus on a specifi c weed, such as nutgrass, or it may encompass many varieties, herbicides and application regimens.

OVERHEAD TO BELOW GROUND

Still a new technology in agriculture, the unmanned aerial vehicle, also known as a drone, is soaring through the skies taking overhead pictures of peanut crops. What can these photos tell researchers? Well, that is being studied now.

Virginia Tech Tidewater Agricultural Research and Experiment Center associate professor and Extension specialist Maria Balota is looking at using UAVs in various ways. Can they be used to evaluate variety breeding plots for drought tolerance? What type of UAV sensor is most useful in distinguishing colors of foliage that is stressed or wilting?

In her project, “Can UAVs Be Used For Peanut Variety Selection?” Balota discovered a high-resolution selection system that could be used by breeders to expedite crop development to increase yield and quality.

North Carolina State University peanut breeder Jeff Dunne

DEVELOPMENT TO CONFIRMATION

If it doesn’t rain, not much else matters. Water is an essential element for growing peanuts. Because it often doesn’t rain, irrigation is needed. Providing what the crop needs through irrigation is costly.

University of Georgia agriculture economists estimate irrigation’s average cost is $7.50 per acre-inch of water applied. For 1,000 acres at 10 inches of irrigation, that’s $75,000. It’s obvious why every drop needs to be used by the crop and not wasted. Water has been and will continue to be a precious commodity to be preserved and used wisely.

UGA Extension irrigation specialist Wes Porter conducts research on advanced irrigation scheduling technology.

Over several projects, Porter found that the UGA Smart Sensor Array or WaterMark probe system often has the highest irrigation water-use efficiency and also the highest yield. Other methods he has studied include IrrigatorPro, UGA EasyPan and PeanutFARM. Porter says producers should choose a method based on their comfort level with the technology and their irrigation management style.

With modern technology and current varieties, Porter and

With a UAV and a cell phone, NCSU peanut breeder Jeff Dunne is developing a method to take trial plot leaf spot readings quicker.

did just that. In his study, “Mapping Leaf Spot Resistance For Marker-Assisted Selection,” Dunne used a UAV to determine levels of leaf spot resistance in trial plots.

Dunne says, “We used drone and cell phone images to rapidly take ratings on both defoliation and leaf spot lesions. The idea is to evaluate 220 lines in the field using drone imaging and walking through the plots taking cell phone images. The images are uploaded, and image software with a customized algorithm analyzes the plots. With this approach, ratings can be taken objectively and more quickly than the breeder walking the field. When analysis is complete, I can look at the best lines and make selections for further development.”

With research from scientists like Balota determining the best sensors and cameras, peanut breeders like Dunne are using it to develop leaf-spot resistant peanut seed quicker.

Rain-out shelters help researchers determine the most water-use efficient irrigation scheduling methods and also whether the traditional water-use curve is still valid.

other researchers began to question whether the traditional peanut water-use curve, which is based on historical evapotranspiration data, was still accurate. At times, research is needed to confirm the relevance of commonly used precepts or to update them.

Today’s peanut research is used to develop new techniques and corroborate old guidelines.

Thanks to the International Peanut Genomic Initiative, funded in part by growers through the National Peanut Board, the peanut genome was sequenced. In the process, researchers discovered markers, a string or sequence of DNA, located near the DNA sequence of the desired gene. Since these molecular markers and the genes are close together on the Using marker-assisted selection, getting to the third backcross stage takes a few years compared to 12 to 15 before. Researchers are now selecting these leaf-spot-resistant varieties for possible release or further crosses with soilborne disease resistant material. same chromosome, they tend to stay together as each generation of the plant is produced. Currently, U.S. Department of Agriculture Agricultural

In order to find markers associated with specific traits, Research Service peanut breeder Corley Holbrook is develboth genetic and phenotypic (visual or measurable) data oping leaf-spot resistant peanut varieties using markers determust be gathered and correlated. In a test set of plants mined by fellow USDA ARS scientist Peggy Osias-Akins. He designed specifically for identifying markers associated with is currently in the third backcross on some of the selections. a certain trait, DNA is taken from each plant and analyzed. Holbrook says,“The traditional breeding approach that The same plants are examined for the specific trait, for exam- has been going on for many years, we can do a lot faster with ple leaf spot resistance, in the field for a period of years. This marker-assisted selection. In the old days, it would take 12 is called phenotyping and is necessary to determine which to 15 years to get to backcross three because it took years to markers correlate to what trait. make selections and identify progeny you want to backcross.

When the specific markers are always present in plants With marker-assisted selection, we have completed the origshowing leaf spot resistance, then peanut breeders can use inal cross and three backcrosses in four years. We are now those markers to select leaf-spot resistant plants in their identifying the lines we hope to release as leaf-spot resistant breeding programs. Whatever a peanut plant or seed can varieties.” exhibit – disease resistance, drought tolerance, reduced skin From the laboratory where the DNA of the peanut was slippage, improved blanchability or flavor attributes – there mapped to the field where leaf-spot resistant varieties are is a marker for it. Many researchers are working to determine being grown and selected, grower-funded research is making it marker-trait associations in peanut. happen. The outcome will be a worthy return on investment.

SEED TO TABLE

Consumers are an important component of research. To be a tasty product, peanuts must have good flavor. To be processed efficiently, they also need to be the correct size and shape, among other traits. Peanut researchers cover all of the necessary topics to get peanuts from the planted seed to the consumer’s table.

It is critical for Virginia-type peanuts to have excellent roasting characteristics with desirable flavor and textures. Roasted peanut flavor qualities are composed of hundreds of different compounds and are, therefore, complex. Research on Virginia-type varieties includes tests of the sensory attribute intensity. Through study panels, scientists quantify such attributes as the roast color, over roast, under roast, sweetness, nutty aftertaste, bitterness, astringence and the level of fruity/fermented or stale/cardboard flavor notes.

Production research is critical, but will the consumer eat it and come back for more? The many facets of consumers’ tastes and preferences must be studied as well.

A REMARKABLE RETURN ON INVESTMENT

Is the farmer’s investment in peanut research worth it? Well, that takes another study.

In 2019, the NPB commissioned an economic study to measure the return of peanut producers’ investments in the marketing and research funding programs. An economic evaluation, conducted by Cornell University, found that each dollar invested in the checkoff program between 2014 and 2018 returned $9.74 to the peanut industry.

The study emphasized had there not been any NPBsponsored production research over this period, peanut yields would have averaged 10% less at 3,462 pounds per acre, compared with 3,880 pounds per acre. Without marketing activities over the most recent five-year period, total domestic peanut demand would have averaged 14.4% less.

Through state and regional organizations, this research works to maximize value, encourage collaboration and eliminate gaps. It all adds up to sustainable and profitable peanut production for farmers. RR