Scott Harkcom, agronomy farm manager, lines up his tractor to cultivate some of the 600 acres he uses to grow crops such as field corn, wheat, and alfalfa. The agronomy farm is the largest Penn State research farm.

As manager of the agronomy farm, the college’s largest field research facility, Scott Harkcom and his staff work more than 600 acres and manage the agronomic crops on the Ag Progress Days site. He has four full-time employees and farm equipment ranging from a small garden tractor to a six-row combine capable of harvesting a 40-acre field. “A lot of large tractors and combines are useless in our smaller plots,” he says. “However, we like to use equipment similar to that used by the average Pennsylvania farmer to get as close to their experience as possible.”

Harkcom lives on the agronomy farm, renting one of the property’s original farmhouses from the University. He and his crew have specialties—one person does most of the fertilizer applications, another does all of the corn planting—but all employees find themselves doing a variety of jobs. After receiving faculty requests for land allotments, Harkcom sits down with field maps, soil test reports, and his computer database to meet each specific crop research request. Harkcom also is in charge of marketing all crops produced on the farm. About 50 percent of the farm’s output goes to the dairy and animal science department, and Harkcom sells the rest on the open market to help defray operating expenses.

“We set up 50 to 60 separate research projects each year,” Harkcom says. “One of our biggest challenges is preventing wind drift during herbicide applications. If we spray on a windy day, drift really can damage other research plots.” The agronomy farm also is the site of a long-term crop rotation experiment that has examined the effects of different crop rotations on soil fertility for the past 30 years. Harkcom and his crew do all the necessary field work and data analysis for that project.

Weed scientist Bill Curran raises a variety of crops on the agronomy farm. Unfortunately, all his crops are weeds. “We will do just about anything for the faculty,” Harkcom says. “One year, Bill asked me to use a combine to harvest some ragweed that had grown up in a harvested field so he could use the seeds for his research. That might be the only time anyone has ever harvested ragweed.”

One of Curran’s recent projects involves burcucumber, a native plant that has become an annoying field weed in southeastern Pennsylvania. “This woodland and meadow weed can often be found in the bottom areas along rivers,” Curran says. “As more farmers start to farm these bottomlands, they drag the weed seeds into their fields.”

Weed scientist Bill Curran lifts a tangle of burcucumber, an invasive weed that can easily grow 30 feet long. Burcucumber can choke out other plants and cause tangles in combines and silage choppers.

Burcucumber is a summer annual vine that resembles a commercial cucumber plant in its early growth stages. However, instead of producing an edible fruit, this weed produces a hard, spiny seed cluster that requires farmers to wear heavy gloves when handling it. The vines can easily grow more than 30 feet long, choking other plants and causing wraparound tangles in combines and silage choppers. “It’s a pretty ominous-looking plant,” Curran says. Burcucumber seeds also are highly dormant and can survive deep in the soil. In any one year, only 5 to 10 percent of burcucumber seeds germinate, making consistent long-term control impossible.

“You’ll have this weed for your lifetime and maybe your children’s lifetime,” Curran says. “Farmers can spray it and kill the surface plant, but herbicides don’t kill the seeds underground, so this weed will keep coming up.”

Curran is testing whether tillage methods and reducing crop residues can help control burcucumber emergence. In a two-year study, his research team found that using no-till practices and reduced amounts of crop residue can significantly reduce burcucumber emergence, and weeds that do emerge can be controlled with herbicides. “Weed control is all about trying to find the plant’s Achilles’ heel,” says Curran. “All pests have innate weaknesses—we just have to discover them.”

Valuable crops can be attacked by a variety of maladies, but none are more capricious than a hailstorm, which can reduce a field to stubble in minutes. Agronomist Greg Roth is using the agronomy farm to study the effects of hail on field corn. “After a hailstorm, leaves are shredded or gone and most producers think the crop is lost,” Roth explains. “But researchers in the Midwest have shown that corn can recover.”

About 30 percent of the corn in Pennsylvania is grown to feed animals as nutritious silage. Stalks, leaves, and ears are chopped up during harvest, then fermented. When corn is defoliated by a hailstorm, particularly in the early growth stages, the plant’s development is hindered, but it continues to grow.

Roth, in collaboration with University of Wisconsin researchers who are duplicating his experiments in that state, is starting
a three-year series of hail defoliation experiments to discover how much nutrient value the damaged corn retains as silage.
“Frequently after a hailstorm there are disagreements on what the yield loss actually is and what an insurance company says it is,” Roth says. “If a mature stand of corn is damaged by hail, the silage may actually increase in quality because you end up with more grain and less leaves in the silage. Conversely, if early growth plants are hail-damaged and ears never form, then the loss of plant material means a drop in yield and quality. We are trying to establish a quality scale for silage obtained from corn damaged at different stages of development.”

Although university professors are influential people, few academics can conjure up hailstorms at will. Roth simulates hail damage by trimming off corn leaves during four stages of corn growth. He simulates storm intensity by defoliating plots by 25, 50, and 100 percent. At the end of the growing season, the corn will be harvested as silage and tested for nutrient quality. The data will be used to determine exactly what kind of financial loss value can be given to a hail-damaged crop.

Agronomist Greg Roth cuts leaves from corn plants with lawn-trimming shears to simulate hailstorm damage. He is studying how much nutritional value hail-damaged corn retains as silage.