Southwest Missouri Field Crop Report for July 31, 2013

Contact: Jill Scheidt, agronomy specialist

Tel: (417) 682-3579

E-mail: scheidtjk@missouri.edu

LAMAR, Mo. –Jill Scheidt, agronomy specialist with University of Missouri Extension in Barton County, scouted area fields on July 31 to prepare this week’s field scouting report.

“The majority of the corn scouted this week, looks to have pollinated good and kernels are beginning to develop.  In fields that did not receive rain during pollination, ears had spotty kernels that pollinated,” said Scheidt.

A very small amount of rust was seen on leaves this week but Scheidt says it is rarely something to worry about.  Corn rootworm beetles were seen on silks.

“There is no need to spray for insects feeding on silks if pollination is complete.  If pollination is less than 50 percent complete and silks are clipped to less than half an inch, treatment is justified,” said Scheidt.

POD WORMS

“Do not misidentify green clover worm with pod worms, also known as corn earworm.  The two worms are different in that one is beneficial and the other is not,” said Scheidt. 

Green clover worm carry a fungus that kills pod worms.  Green clover worm can also be found in soybean fields and may feed on foliage, but do not cause economic damage.

Green clover worm and pod worm are similar in color but can be differentiated by counting the number of abdominal pro-legs.  Green clover worms have three abdominal pro-legs and pod worms have four abdominal pro-legs. 

BLISTER BEETLES

“Blister beetle feeding was seen, but I could not find any actual beetles.  Blister beetles are narrow, cylinder shaped beetles with black and yellow stripes down the back,” said Scheidt.

Again, defoliation thresholds for soybeans are 30 percent defoliation before bloom and 20 percent defoliation during or after bloom.

Herbicide injury was seen on a few soybean fields.  It is important to consider the growth stage of soybeans when spraying herbicides that can cause injury to the leaves.

“Soybean plants need to be in optimum health just before and at flowering to produce an optimum yield.  If you are irrigating, before and at flowering are also critical times to water the field,” said Scheidt.

MORE INFORMATION

The weekly field scouting report is sponsored by University of Missouri Extension and Barton County Extension. For more information on this scouting report, or to learn how to receive it a week earlier by telephone, contact the MU Extension Center in Barton County, (417) 682-3579.

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The direct links for this photos are http://www.flickr.com/photos/muextension417/9413800574/ for the Pod Worm and http://www.flickr.com/photos/muextension417/9411034079/ for the Green Clover Worm.