sealPurdue News

October 1996

This year's wet weather threatens crops in 1999

WEST LAFAYETTE, Ind. -- This year's weird weather has focused farmers' attention on the fall harvest. That's fine, but they also need to think about how it will affect crops in 1998 and 1999, says Purdue University plant disease specialist Don Scott.

"With changes toward reduced tillage, we've got some major problems on the horizon," Scott says. "Certain disease residues survive two to three years, so you can't figure that rotating from beans to corn next year will mean no problems."

In fact, if a bean field goes to corn for the next two years, then back to beans, farmers still could have big disease losses in 1999. Because wet weather forced farmers to plant beans for the second year in a row in some fields this summer, certain disease problems have had a chance build to high levels, Scott says.

"Soybean cyst nematodes, brown stem rot and sclerotinia white mold, for example, may be more of a problem two years from now when farmers go back to soybeans," he says.

Farmers who are losing crops to these diseases now should keep track of their problems and consider planting disease-resistant soybean varieties two or three years down the road, Scott says. Farmers who don't keep track may lose out.

"I often am called in when disease problems are severe and am asked what farmers can do," Scott says. "By that time it's too late -- there's nothing to do. But if they'd planted disease-resistant seeds, they could have avoided problems."

CONTACT: Scott (765) 494-4627; e-mail,

Owner education could save unwanted pets

WEST LAFAYETTE, Ind. -- Of the nearly two million dogs brought to animal shelters by their owners each year, up to two-thirds might still be living at home if their owners took the pets to obedience classes or visited the veterinarian more often, according a Purdue University study.

An additional one-third of the dogs might still be pets if their owners had sterilized them or had realistic expectations about the pet's behavior.

"Dogs that had not been in obedience classes were about 3.5 times more likely to be relinquished to a shelter," says Dr. Lawrence T. Glickman, professor of veterinary epidemiology and environmental health and one of the study's authors. "Dogs that hadn't been to the veterinarian at all were about 13 times more likely to be given up than dogs that had been at least twice. Veterinary care and obedience classes may increase the owner's bonding to the dog."

The study compared 285 owners who had given up their dogs with 748 who still had dogs. About half of the 4 million total dogs that end up in shelters each year are euthanized.

The study also found that only about one-fourth of the survey households that sought veterinary care said the doctor routinely offered advice on behavior or training.

"Visiting a veterinarian is a chance for the owner to learn what's normal and abnormal behavior and thus be more tolerant of the pet," Glickman says. "It's pretty clear from the study that increased education and outreach efforts by veterinarians, dog clubs and other animal-welfare groups could substantially reduce the number of dogs handled annually by shelters, of which about half are put to sleep."

The researchers also did a parallel study on common factors among owners who gave up their cats for adoption. Among the findings: A cat kept outside rather than as a house pet was nearly three times more likely to end up in a shelter, and unsterilized cats were 2.5 times more likely to be relinquished. Approximately 6 million cats (pets and strays) are brought to shelters each year, with about two-thirds being euthanized.

The study was funded by the Ralston Purina Co., two animal-welfare trust funds, and Purdue's Center for Applied Ethology and Human-Animal Interaction.

CONTACT: Glickman, (765) 494-6301; e-mail,

Purdue introduces CD-ROM to detect herbicide damage

WEST LAFAYETTE, Ind. -- Herbicide damage on ornamental plants will be easier to diagnose with the help of "Picture the Damage!" a photo CD developed by Purdue University Extension specialists.

More than 500 four-color images of trees, shrubs, groundcovers and herbaceous perennials will give plant diagnosticians, ground managers, agrichemical specialists, horticulturists, weed scientists, insurance claims adjusters and others the resources to help them assess herbicide damage.

According to Michael Dana, Purdue University Horticulture Extension specialist and developer of "Picture the Damage!" the CD-ROM will make diagnosis simpler and faster.

"It is a tool to help make accurate assessment or decisions of whether observed plant damage is due to herbicides," he says. "With additional software, images can be captured and printed, which would be useful to send to a client who calls in to ask what certain damage looks like."

The program, available for $39.95, allows users to select one of 21 plants they want to see and select the herbicide they suspect caused the damage. If the pictures don't match the damage on the plant, the user can return to the main menu.

"Picture the Damage!" is a Kodak Portfolio CD that can be viewed from a computer equipped with photo CD-compatible CD-ROM or from an ordinary TV screen connected to a photo CD player. It may be ordered by calling (765) 494-6794 or writing: Agricultural Communication Service, Media Distribution Center, 301 S. Second St., Lafayette, IN 47901-1232.

CONTACT: Dana, (765) 494-5923

Effectiveness of warnings may depend on user, expert says

WEST LAFAYETTE, Ind. -- Why don't people heed warnings on products such as chainsaws, ladders and PTOs? The answer has to do with how people weigh benefits vs. risks when making a decision, says a Purdue University expert on warning label design.

"If someone perceives a benefit in not following a certain safety rule or warning, they are likely to violate the rule or disregard the warning," says Mark Lehto, associate professor of industrial engineering.

For example, in a study published in the journal Ergonomics in a special issue devoted entirely to warnings, Lehto found only one out of 54 subjects heeded the warning on a glue label to ventilate the room while using the product, despite the glue's foul odor.

"This study suggests that if someone's main goal is to complete a task, the benefits he perceives in finishing may outweigh the risks of skipping a safety step," Lehto explains. "Similarly, if someone's out to have a good time, the benefits he sees in having fun may outweigh the risks he sees in driving drunk. If you want people to behave more safely, you need something more dramatic than a warning label."

Increasing numbers of product liability lawsuits point to a need for improved criteria for deciding when and how to provide warnings, Lehto says. He has spent much of his career developing national and international guidelines for making warnings more effective.

Products that emit warnings, such as smoke detectors, could be made more effective if they took advantage of individual preferences, Lehto says. He is looking into a relatively new concept -- adaptive warning systems -- that may better meet the individual behavior patterns of a user.

"If a warning system such as a smoke detector is too sensitive, it will almost always detect a problem -- but it will also give off a lot of false alarms," Lehto explains. "After a while, some people won't pay attention to it any more and might react by turning it off completely, which isn't safe." With an adaptive smoke detector, individuals could adjust the device to be very sensitive or not-so-sensitive, depending on their preferences and lifestyles, he says.

Lehto and his colleague Jason Papastavrou, assistant professor of industrial engineering, are conducting experiments to determine whether people can adjust an adaptive warning system to their own behavior and sensitivity without jeopardizing safety.

CONTACT: Lehto, (765) 494-5428; e-mail,

Gift provides lab support for pets with cancer

WEST LAFAYETTE, Ind. -- A gift from an Aguanga, Calif., couple to Purdue University's School of Veterinary Medicine has made it possible for the school to devote a laboratory to the study of cancer in pet animals.

Homer and Dolores Harris pledged $250,000 to the school's Comparative Oncology Program. The gift will equip a lab named in their honor, the Harris Animal Cancer Laboratory. The lab will make it possible for Purdue veterinarians working in cancer research to study how the disease occurs in animals, how it spreads, and why the immune system doesn't respond to it.

"The Purdue Comparative Oncology Program examines and treats cats and dogs with naturally occurring cancer and explores more effective ways than the traditional anticancer drugs to treat the disease in pets and in people," says Dr. Deborah W. Knapp, a co-director of both the program and the lab. "Some specific forms of cancer in animals are similar to cancer in people, including cancer of the bone, bladder and prostate."

Knapp, assistant professor of comparative oncology, says the lab also will support research in the Purdue Cancer Center.

The oncology program, which began in 1979, sees about 1,000 new patients each year. More than 90 percent of the owners choose to have their pet receive some form of therapy, Knapp says.

Knapp says pet owners who wish to use the Comparative Oncology Program's services should work with their regular veterinarian to arrange an appointment with one of the program's staff.

CONTACT: Knapp, (765) 494-1107

Compiled by Steve Tally, (765) 494-9809; e-mail,
Purdue News Service: (765) 494-2096; e-mail,

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