University of Missouri Extension

Barton County

June 2011 Crop Scouting Reports

Field Scouting Report for June 29…

Continue Checking Corn Fields for Japanese Beetles

Jill Hankins, agronomy assistant with University of Missouri Extension in Barton County, scouted fields south and west of Lamar on June 27. She found armyworm, corn rootworm beetle and grasshopper feeding on corn in the 10-12 leaf stage. “None of the insect feeding was great enough to cause concern,” said Hankins.

If a grower is seeing damage, insecticide is justified for armyworms when 75 percent of the corn has damage. Insecticide is justified for corn rootworm beetle when one or more corn rootworm beetles can be found per plant and the silks are being clipped to one-half inch.

“Corn is nearing or at the silk stage, so watch for three or more Japanese beetles per plant clipping the silks and preventing pollination from occurring,” said Hankins.

The soybeans that Hankins scouted were in the flowering stage and had some bean leaf beetle feeding but not enough to cause concern. “I saw quite a bit of defoliation from Japanese beetle feeding on the edges of the field. Once I got into the field the damage was significantly less and did not warrant concern inside the field,” said Hankins.

For growers that are seeing more than 30 percent defoliation due to Japanese beetles, Wayne Bailey, state entomologist specialist, says Hero and Cobalt work best, they also take care of grasshoppers and stinkbugs and they give two to three weeks of protection.

For more information on this scouting report or to learn how you can receive it by telephone each week, contact the MU Extension Center in Barton County at (417) 682-3579. These weekly field crop scouting reports are sponsored by MU Extension in Barton County and the Barton County Soil and Water Conservation District.

PHOTOS AVAILABLE: Photos of the various diseases discussed in this release are available for viewing or downloading at www.flickr.com/MUExtension417.

Click here for PDF file Audio Report --- http://tinyurl.com/634dylh

Soybean Foliation Chart

http://ipm.illinois.edu/fieldcrops/insects/japanese_beetles/images/2_03.jpg

Spraying for control of Japanese Beetles is justified with a 20% defoliation after podding. Spraying to control Japanese Beetles is justified with a
30% defoliation before podding.

Field Scouting Report for June 22…

Rootworm Beetles and Bean Leaf Beetle Create Concern this Week;
Be Checking Corn Fields for Japanese Beetles

Jill Hankins, agronomy assistant with University of Missouri Extension in Barton County, scouted fields north of Liberal on June 20. She scouted some corn fields that were in the tenth to twelfth leaf stage.

“There was a low number of feeding from fall armyworms but it was not in the whorl; so there is no cause for concern. I also saw a couple corn rootworm beetles; they were not in high enough populations to cause concern,” said Hankins.

In area soybeans fields that were scouting, most were in the first to second trifoliate stage. “I saw minor feeding by bean leaf beetle in these fields but insecticide is justified when the leaves show 30 percent defoliation before podding,” said Hankins. “After pods are put on, insecticide is justified when the leaves show 20 percent defoliation.”

Grape Colaspis were also seen, according to Hankins, but they are a minor pest and do not cause significant damage.

Japanese Beetles are also beginning to show up. According to Hankins they are not a concern until the corn pollination time. “They will eat the silk and prevent pollination of the kernels. Insecticide is justified with three or more Japanese beetle per ear tip during pollination,” said Hankins.

PHOTOS AVAILABLE: Photos of the various diseases discussed in this release are available for viewing or downloading at www.flickr.com/MUExtension417.

Click here for PDF file Audio Report --- http://tinyurl.com/63cmc9y

Bean Leaf Beetle Bean Leaf Beetle feeding on soybeans

Grape Colapsis Unknown insect eggs

Field Scouting Report for June 15…

Wheat, Soybeans and Corn all Look Good;
Some Damage from Unidentified Pest Found

Jill Hankins, agronomy assistant, University of Missouri Extension in Barton County, west of Lamar in the Iantha area on June. 15.

"The wheat looked good, not much to say since it was about ready for harvest," said Hankins.

Most of the corn fields were between the seventh and tenth leaf stage. "The corn looked healthy and I saw that the thrips damage was repaired. I saw a small amount of worm feeding in on the upper leaves of the corn," said Hankins.

The soybeans were in the first and second trifoliate. "I saw brown lesions from pre-emergent herbicide applications; this is nothing to worry about, the soybeans will grow out of this," said Hankins.

Remember to look out for green stinkbugs as they can cause delayed senescence.

"I did find some damage on both the soybeans and corn from an unidentified pest and I have sent samples to the University of Missouri for identification," said Hankins.

PHOTOS AVAILABLE: Photos of the various diseases discussed in this release are available for viewing or downloading at www.flickr.com/MUExtension417.

Click here for PDF file Audio Report --- http://tinyurl.com/3dpd26x

Unknown insect feeding on corn

Unknown insect feeding on soybeans

Field Scouting Report for June 7…

Watch for Stinkbugs in Soybeans

Jill Hankins, agronomy assistant, University of Missouri Extension in Barton County, scouted fields west and north of Lamar on June. 6.

The soybean fields were just pushing through the soil but some stinkbugs were found on the border rows. “Stinkbugs cause delayed senescence, leaving the pods, leaves and stems green for three weeks past the point of normal dry down,” said Hankins.

The threshold for green stinkbugs is one per foot of row. If stinkbugs are over the threshold, spraying is justified with insecticides like Warrior.

According to Hankins, the wheat looked good in the soft dough stage. “I did find some armyworms but not at threshold levels. Threshold levels for armyworms in wheat are four armyworms per square foot,” said Hankins.

Last week in the area around Golden City, Mo., some farmers reported high armyworm infestations and sprayed for them. Hankins also looked at corn in the sixth leaf stage up to the tenth leaf stage.

“I saw insects feeding from thrips on the lower leaves, but it is not of concern because beneficial bugs will take care of them. Keep on the lookout for armyworms in corn as well; threshold levels for armyworms in corn are when 25% or more of the plants are damaged,” said Hankins.

Click here for PDF file Audio Report --- http://tinyurl.com/3v5lxku

Army worms feeding on wheat Thrips on corn

Field Scouting Report for June 1…

Corn and Wheat Both Healthy in Scouted Fields

Jill Hankins, agronomy assistant, University of Missouri Extension in Barton County, scouted fields west of Lamar on June 1.

Hankins says she found the wheat in the milk stage. Some heads were damaged by hail and barley yellow dwarf virus was present on the flag leaf.

"I also may have seen fusarium head scab on wheat heads. Samples have been sent to the lab for conformation," said Hankins. "It is important to remember that fungicides cannot be applied to the wheat anymore because they are off label now."

No armyworms or other harmful insects were seen at damaging levels.

Corn in the scouted areas was in the seventh leaf stage and showing some scarring from a previous hail storm.

"Overall, the corn looked healthy. A little bit of worm feeding was observed but not enough plants were damaged to cause concern," said Hankins.

No armyworms have been seen yet but, Hankins says to be sure to keep on the lookout for armyworms because they can cause serious damage to the field in a matter of two to three nights.

Click here for PDF file Audio Report --- http://tinyurl.com/4xv65o8

Corn disease Insect feeding on corn

Wheat disease

Hail damage on wheat