Southwest Missouri Field Crop Report for Sept. 4, 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 Sept. 4 to prepare this week’s field scouting report.

“A lot of corn is nearing black layer, which means kernels continue to accumulate seed weight until physiological maturity, or black layer, is reached. It normally happens about 60 days after silking or 20 days after denting,” said Scheidt.

To observe the milk line, or how close corn is to black layer, break a corn ear in half and observe the cross-section of the top half of the ear. Kernels will have 28-35% moisture content at black layer.

Downy mildew is more prevalent this year, in uppermost canopy of soybeans. According to Scheidt, it is usually not economical to spray a fungicide for downy mildew. Heavy dews encourage fungus growth but hot, dry weather slows it down.

Sudden death was also seen in a few fields. Sudden death is caused by a fungus in the soil. If conditions are cold and wet during early growth stages and reproductive stages of soybeans, SDS can be more pronounced.

“If SDS shows up in a part of the field that was planted earlier than another part, SDS usually does not spread from plant to plant, because it is more dependent on the soil conditions during susceptible stages of growth. There is no fungicide treatment to control SDS, more resistant varieties must be selected to protect against SDS,” said Scheidt.

Another area problem is podworm moths which like to lay eggs in an unclosed canopy in soybeans. Identify moths by the black banding on the hind wings. Eggs hatch 7-10 days after moth flights. Six weeks after moth flights is when podworms could stop foliage feeding and begin feeding on pods.

“Don't spray unless podworms reach threshold, which is 1 podworm/ft, because beneficial clover worms carry a fungus that kill podworms, and may take care of the podworms without a need to spray an insecticide,” 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.