Farms.com Home   News

Nematode Updates - Corn Parasitic Nematodes

By Jamal Faghihi
 
This has been a cool and wet spring so condition must be right for the needle nematode to cause damage to corn grown in sandy soils.
 
Needle nematodes, the most yield-limiting nematodes in corn. It needs a cool and wet condition to cause problems in corn. But some other nematodes, like lance and lesion nematodes, do not require those conditions to be a problem. This time of the year these nematodes are looking for food and they are eager to attack young corn roots. So if condition is right in your area, cool, wet and sandy soil, needle nematodes could be a problem this year. If you have had problems on corn before, and weather conditions is in the nematodes’ favor, you might consider sampling for nematodes. In this case, you may wish to send the entire root system with adjacent soil to the Nematology Laboratory, address below, at Purdue University for analysis. Samples must be kept cool and prevented from drying. The best time to sample for needle nematodes is 4-6 weeks after germination.
 
Under high nematode pressure, roots do not develop normally. The roots are truncated and resemble herbicide injury. Similar symptoms are present where lance nematodes are causing a problem. Lesion nematodes, however, will not cause the described root symptoms. But, symptoms for most plant parasitic nematodes are usually in patches and do not follow a uniform pattern in the field.
 
Often needle nematodes disappear when soil temperature rises above 85°F. So the best time to sample for needle nematode is now. You can sample for other corn parasitic nematodes through out the growing season.
 
You have to observe whether conditions that are favorable to needle nematodes and enable them to cause yield loss. These conditions are specific to needle nematodes and do not apply to lance and lesion nematodes. The latter species feed throughout the season and they could be a problem in all types of soils and weather.
 
 
Healthy (left) compared to needle nematode damaged plant (right).
 
Healthy (left) compared to needle nematode damaged plant (right).
 
Corn seedling roots damaged by needle nematodes.
 
Corn seedling roots damaged by needle nematodes.
 

Trending Video

Looking at Lambs

Video: Looking at Lambs

SBM takes a visit to see our friend Josh Butler from J&E Meats in Croton. Josh gives us a behind the scene look of their lambing operation. Also, get a chance to see some sweet baby lambs.