AgriLife Research zeroes in on potato disease insect

Jun 27, 2012

Do potato psyllids migrate from one location to the next, starting in northern Mexico and moving northward as the potato season progresses, or are psyllid populations local?

Knowing whether the insects are migratory or local could help more efficiently manage the insects which are increasingly inflicting damage on the country's potato industry, according to scientists working on the project.

A study that is being done as a part of the national Zebra Chip Specialty Initiative involves Dr. Arash Rashed, Texas AgriLife Research vector ecologist, and Dr. Charlie Rush, AgriLife Research plant pathologist in Amarillo and lead on the national initiative.

The carried by the psyllid is Candidatus Liberibacter solanacearum. When the psyllid feeds on a , the bacteria is transmitted into the plant and causes the disease known as zebra chip of potato, Rush said.

While it has no effect on human health, can cause entire loads of potatoes to be rejected by the potato chip industry because of the negative effect it has on chips and fries, which appear as burned when fried, he said.

"It is generally believed that psyllids migrate from Mexico to the Canadian border," Rashed said. "While that is a possibility, we want to see if there are local populations and if there are winter breeding sites."

He said through field, greenhouse and laboratory studies, and in collaboration with potato producers and other scientists, they are studying various aspects of pathogen-plant-vector interactions. One of these studies is addressing the effects of , topography, and air currents on psyllid populations and their movement pattern.

"We have set up traps in Pearsall, Seminole and Kermit, Springlake, Bushland and Dalhart," Rashed said. "We monitor changes in psyllid numbers in natural vegetation around the potato fields. We also test for their infection status, with the objective to identify pathogen reservoirs during winter when the cultivated host is absent."

He said initially they saw psyllids in Pearsall, but not Olton and Springlake. Then they began seeing more than a thousand on traps from those regions, an unusually high number.

"Psyllid numbers, however, dropped in natural vegetation during April and May," Rashed said. "This coincided with potato-emergence time, when psyllids began to infest field edges. We don't know if it was a one-time thing, or a yearly reoccurring phenomenon.

"Our survey will continue throughout the next year to address this question," he said.

"We also evaluate the percentage of insects that are carrying the pathogen," Rashed said. "Although only a low percentage of psyllids are actually carriers, if the population is high, it also means there are a lot of positive psyllids."

Moreover, he said, the damage caused by psyllids is not just through transmitting the pathogen as they also induce another condition in potato plants, called "psyllid yellows," by simply feeding on the plant tissue.

While it is too early to make any conclusions on what environmental factors affect the populations, he said they believe early spraying of the fields and seed treatments are the most reasonable way to lower the impact.

Other control approaches such as eliminating volunteer potatoes, which can be ideal hosts for psyllids prior to cultivated emergence, need to be integrated to increase the effectiveness of chemical control early in the season, Rashed said.

Explore further: Bangladesh meet begins to save endangered tigers

add to favorites email to friend print save as pdf

Related Stories

Biobased approaches examined in fight against zebra chip

Feb 13, 2012

Thanks to investigations by scientists-turned-detectives with the U.S. Department of Agriculture (USDA) and other agencies, potato growers in the western United States and abroad now know the identities of ...

People only eat 1 when the chips are brown

Jul 16, 2008

Dr. Don Henne isn't wasting his degree when he's standing by the deep fryer waiting for potato slices to turn brown. He's conducting research that will help the potato industry and consumers.

Bacterium Identified as Potato Disease Culprit

Oct 14, 2009

(PhysOrg.com) -- Studies tying a new species of Candidatus Liberibacter bacteria to zebra chip (ZC) disease in potato should speed efforts to better protect the tuber crop from costly outbreaks.

Recommended for you

Bangladesh meet begins to save endangered tigers

12 hours ago

Some 140 tiger experts and government officials from 20 countries met in the Bangladeshi capital Dhaka on Sunday to review progress towards an ambitious goal of doubling their number in the wild by 2022.

Plant life considered in ecosystem synergies

Sep 12, 2014

Local flora species involved in UWA's Ridgefield Multiple Ecosystem Services Experiment are helping researchers to better understand agricultural processes including efficient nutrient cycles and maintaining ...

Potato ravaging pest controlled with fungi

Sep 12, 2014

Approximately six thousand hectares of Veracruz, in the west coast of Mexico, are dedicated to the production of potato (Solanum tuberosum). During the past 30 years, the fields of the Cofre de Perote area ...

User comments : 0