Skip to main content

Stink bug and cotton seed rot problem solved

A mystery about a disease that can destroy up to 15 percent of a cotton crop in the southeastern United States has been solved by Agricultural Research Service (ARS) researchers. The work could save cotton crops and prevent unnecessary insecticide spraying. In 1999, scientists reported an emerging seed rot disease that was discoloring seeds and darkening fibers in cotton bolls in the southeastern states, making the crops unmarketable. It quickly spread throughout the southeastern Cotton Belt.

To study the problem, plant pathologists Gino Medrano and Alois Bell of the ARS Cotton Pathology Research Unit, part of the Southern Plains Agricultural Research Center in College Station, Texas, focused on the southern green stink bug (Nezara viridula L.) as the disease-transmitting culprit.

In the greenhouse, they infected cotton bolls with suspect bacteria, using a needle to penetrate the boll wall and mimic a stink bug's bite. The results showed the needle created a pathway for the bacteria to enter the boll and damage it. The researchers used a strain of the bacterium Pantoea agglomerans in the research, but other bacteria may also be involved in damaging cotton plants, according to the scientists. In other tests, Medrano and entomologist Jesus Esquivel of the ARS Areawide Pest Management Research Unit in College Station showed why stink bugs sometimes--but not always--cause extensive damage in cotton fields. By infecting bolls at various stages, they found damage levels depend on when infections occur in the fruiting cycle and on how long infection is allowed to spread before harvest. Bolls infected three weeks after flowering are resistant and undamaged. Younger bolls remain susceptible.

Farmers often spray insecticide to combat stink bug infestations. But knowing mature bolls are immune to infections should help farmers decide when to spray. Medrano also is developing a test kit that will offer guidance by telling farmers if stink bugs in their fields are infested with the pathogens that cause the seed/boll rot.

A report on Medrano's work appeared in a recent issue of the Journal of Economic Entomology.
Source: USDA/ARS.

Comments

Popular posts from this blog

Charging Implanted Heart Pumps Wirelessly

Mechanical pumps to give failing hearts a boost were originally developed as temporary measures for patients awaiting a heart transplant. But as the technology has improved, these ventricular assist devices commonly operate in patients for years, including in former vice-president Dick Cheney, whose implant this month celebrates its one-year anniversary. Prolonged use, however, has its own problems. The power cord that protrudes through the patient's belly is cumbersome and prone to infection over time. Infections occur in close to 40 percent of patients, are the leading cause of rehospitalization, and can be fatal. Researchers at the University of Washington and the University of Pittsburgh Medical Center have tested a wireless power system for ventricular assist devices. They recently presented the work in Washington, D.C. at the American Society for Artificial Internal Organs annual meeting, where it received the Willem Kolff/Donald B. Olsen Award for most promising research in

Autism and Eye Contact: Genes very much are involved

We have now a lot of evidence on genetic components in many disorders including neurological in both adults and kids. Autism is one such problem that has many genes involved. Research is still in full swing to find more genes and related pathways. However, one can find autistic features more phenotypically before genotyping. Eye contact is one of them. Studies have shown that autistic kids make less eye contact. This has been shown to have genetic component now. New research has uncovered compelling evidence that genetics plays a major role in how children look at the world and whether they have a preference for gazing at people's eyes and faces or at objects. The discovery by researchers at Washington University School of Medicine in St. Louis and Emory University School of Medicine in Atlanta adds new detail to understanding the causes of autism spectrum disorder. The results show that the moment-to-moment movements of children's eyes as they seek visual information about the

How much people depend on weather reports

Meteorologists on television, radio, online, and in newspapers supply weather reports to the average person over 100 times a month. Surveys demonstrated that the 300 billion forecasts accessed generate a value of $285 per household every year, or $32 billion for the entire United States. Odds are you have already watched one weather forecast today and will probably check out a few more. Accurate, timely forecasts are vital to everyday life, but just how critical may surprise you. Whether at work or play, you probably watch the weather quite closely. Most of us are at the weather person's mercy to know what to wear, what to expect, to prepare for the worst. New research shows the average United States household checks out a weather report more than three times a day. "It impacts pretty much every part of every activity we are involved with for the most part," Jeff Lazo, the director of the Societal Impacts Program at the National Center for Atmospheric Research (NCAR) in B