Researchers get grants to sweeten New York apple crop

Entomologists Art Agnello, left, and Harvey Reissig inspect apples in Geneva, N.Y. Agnello has received one of three grants to Cornell this fall pertaining to apples.

An abundance of crisp, sugary fruit has made the 2011 apple harvest an especially sweet one for New York growers, but Cornell researchers hope to make future crops even more valuable by reducing tree and fruit losses and enhancing production efficiency.

Three recent grants from the New York State Department of Agriculture and Markets (NYSDAM) will enable entomologists, horticulturists and plant pathologists to find solutions to problems that have plagued the state’s apple industry. The New York apple crop, which is the second largest in the United States, was valued at $233 million in 2010, and this year’s harvest is expected to be even larger.

One of the most critical apple production problems for conventional growers is to predictably reduce crop load per tree, so that each tree achieves optimum fruit size and quantity, leading to increased market value.

An $80,000 NYSDAM grant will enable horticulture professor Terence Robinson to apply weather data to predict the apple trees’ carbohydrate supplies and demand status, factors that affect their receptiveness to chemical thinning.

"If this project can help even half of New York’s apple growers achieve optimum fruit size on 25,000 acres of apples, it will have a potential economic impact of $100,000 to $175,000 annually," Robinson said.

Plant pathologist Kerik Cox, a tree fruit disease extension specialist based at the New York State Agricultural Experiment Station in Geneva, N.Y., will be using his $50,000 grant to tackle fire blight, a bacterial disease that can cause apple tree losses as high as 80 percent.

He estimates that preventing such losses could save New York apple growers more than $250,000 per year.

"The source of the problem may be infected mother trees from which nursery budwood is taken," Cox says. "The first step is to authenticate the problem, and then we can develop protocols to help growers prevent it."

Budwood will be collected in a fire blight-infected orchard, and strains of the disease will be isolated. Several new trees will then be inoculated and grafted onto nursery trees. Surviving trees will be planted into a tall spindle production system and monitored over two growing seasons for development of fire blight.

Cornell entomologists Elson Shields and Art Agnello will address the single greatest insect pest challenge for organic apple growers: plum curculio. The insect causes scarring that makes apples and other fruits unmarketable. Growers have struggled to find an organic way to control the pest.

"Plum curculio is a true ’Achilles heel’ for organic growers," says Agnello.

The researchers will use their $77,200 in NYSDAM funding to determine whether a novel biological solution Shields developed to control an alfalfa pest can also be applied to plum curculio.

Shields’ suggested solution -- on-farm rearing and use of insect-attacking nematodes -- has proven a cost-effective success on test farms.

"I believe our work to biologically manage alfalfa snout beetle in northern New York alfalfa fields has established a protocol that will work in New York’s apple orchards with plum curculio," Shields said.

The work also has value for conventional growers, who still see 2-3 percent of crop damage due to plum curculio, despite spraying as many as three times a year, Agnello said.

And the method may help grape growers. Shields will work with Greg Loeb, professor of entomology, who received a $80,000 NYSDAM grant to study the effect of the nematodes on reducing grub populations in eastern New York vineyards as a way to manage Japanese beetles, which cause significant defoliation of grapevines.

Kara Lynn Dunn is a freelance writer.