Featured Research

from universities, journals, and other organizations

Quantifying corn rootworm damage

Date:
December 10, 2012
Source:
University of Illinois College of Agricultural, Consumer and Environmental Sciences
Summary:
Every year farmers spend a lot of money trying to control corn rootworm larvae, which are a significant threat to maize production in the United States and, more recently, in Europe. Researchers have been working on validating a model for estimating damage functions.

Roots damaged by western corn rootworm.
Credit: Image courtesy of University of Illinois College of Agricultural, Consumer and Environmental Sciences

Every year farmers spend a lot of money trying to control corn rootworm larvae, which are a significant threat to maize production in the United States and, more recently, in Europe. University of Illinois researchers have been working on validating a model for estimating damage functions.

Nicholas Tinsley, a doctoral candidate in crop sciences, has refined a model developed in 2009 by researchers at the University of Wisconsin and in Brescia, Italy, to describe the relationship between root injury caused by these pests and yield loss. He used the equivalent of 19 years of data collected by personnel from the Insect Management and Insecticide Evaluation Program in the U of I Department of Crop Sciences.

"Every year we evaluate a number of different management tactics for corn rootworm; these include soil insecticides and Bt traits," Tinsley explained. "We do that at a number of different locations on university research farms."

Tinsley took more than 7,000 data points from field crop insect management trials at Urbana, Perry, Monmouth, and DeKalb for 2005-2011. These trials measured root injury on a 0-3 node-injury scale and mechanically harvested the center two rows of each plot after the crop reached maturity to calculate yield. The results suggested that yield was reduced by 15 percent for each node of roots lost.

Two components had a statistically significant effect variance in the data-location and experimental error. Year had no significant effect.

Tinsley attributes the location effect to differences in weather characteristics and in soil type. "The larva doesn't really burrow through the soil, it exploits existing soil pores. If you have smaller soil pores, it's not able to navigate through the soil and find those roots very well," he said.

The large experimental error indicates that a significant amount of the variability remains unexplained. Tinsley said that this is not surprising considering that yield and proportional yield loss in the experiments varied considerably, probably due to differences among hybrids in yield potential and response to environmental conditions. Other factors that may have contributed to the variability include planting date, planting population, crop emergence, moisture at harvest, and management tactics.

"This not a model that a farmer can use to say, 'What is my yield loss going to be like this year?'" said Tinsley. "You just don't know what some of these things that are affecting the error are going to do."

The model may, however, be useful to help economists to estimate the effect of corn rootworm. "That's when a model like this can become really handy," he continued.

Tinsley said that further directions for this research include developing collaborations with other states. "If we extend to the western Corn Belt where it may be drier, we might start to see differences between two different regions in the relationship," he said.

Another direction is to explicitly model heat stress and moisture stress into the model, perhaps as a covariate. Such an analysis would look at the effects of combinations of factors.

"For example, if I have one node of roots destroyed but I have 10 inches of moisture stress, what's going to happen as compared to what happens if I have one node of root injury but no moisture stress," he explained.

He noted that many studies have demonstrated that often, when there is neither moisture stress nor excessive heat stress, the injury from corn rootworm does not result in significant yield loss.

Another factor to consider is lodging, when plants with root injury fall over. Lodged plants are very difficult to harvest.

"Under certain circumstances, you can have not very much root injury but a lot of lodging and big yield losses," Tinsley said. "Under other circumstances, you can have what seems to be a lot of root injury but if there are no big storms and you don't have any lodging, there may be no yield loss." Future collaborations in the development of this damage function may include lodging in the model.


Story Source:

The above story is based on materials provided by University of Illinois College of Agricultural, Consumer and Environmental Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. A. Tinsley, R. E. Estes, M. E. Gray. Validation of a nested error component model to estimate damage caused by corn rootworm larvae. Journal of Applied Entomology, 2012; DOI: 10.1111/j.1439-0418.2012.01736.x

Cite This Page:

University of Illinois College of Agricultural, Consumer and Environmental Sciences. "Quantifying corn rootworm damage." ScienceDaily. ScienceDaily, 10 December 2012. <www.sciencedaily.com/releases/2012/12/121210145236.htm>.
University of Illinois College of Agricultural, Consumer and Environmental Sciences. (2012, December 10). Quantifying corn rootworm damage. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2012/12/121210145236.htm
University of Illinois College of Agricultural, Consumer and Environmental Sciences. "Quantifying corn rootworm damage." ScienceDaily. www.sciencedaily.com/releases/2012/12/121210145236.htm (accessed April 19, 2014).

Share This



More Plants & Animals News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins