Field Updates 8.7.09

Field Updates 8.7.09

August 7, 2009

Tom Hunt, Extension Entomologist, Haskell Ag Lab, Concord:

Soybean aphids have been on a very slow rise. In northeast Nebraska, aphids are in most fields at very low to low numbers. Consultants are reporting that, in general, they're finding about 25 aphids per plant with that number slowly rising. A few fields had higher numbers.

It's turning out to be a typical Nebraska aphid year, except everything is running just a week or so late. If weather is "seasonable," I expect to see some treatment to start next week (a few may be treated this week). Our aphid action is primarily in August, so growers need to be vigilant. In 2004 we had many fields that peaked at the end of August. With this year's uncommonly cool weather and delays in maturity, scouting should continue through the first couple weeks of September.

Keith Glewen, Extension Educator in Saunders County: Soybean aphids started appearing last week, but by mid-week I hadn't found any fields at economic threshold levels.

Allen Dutcher, State Meteorologist: The recent cold weather is coming to an end, as a ridge pushes eastward. Temperatures will be going up later this week with high humidity indices. Another front is expected to pass through Sunday (August 9) and temperatures should be consistently in the 90s after that. After August 20, there’s a chance of a monsoonal pattern coming into western Nebraska from the southwest U.S. Some of this moisture might move into eastern Nebraska. Recent showers in much of the state have been so spotty, it’s difficult to report on the effect on crops.

Wayne Ohnesorg, Extension Educator in Pierce County: Dryland fields are showing signs of moisture stress and we need rain. Corn has been tasseling and pollinating for about three weeks. We’re starting to see some aphids, up to 40 per plant in some fields.

Jennifer Rees, Extension Educator in Clay County: We need rain as well; dryland crops have been stressed for a while. Corn had good weather for pollination. Beans are approaching the R4 or R5 stage in most fields. In soybean we’ve seen some bean leaf beetles, but no aphids, and in corn we’ve seen some leaf miners. Aerial applications for crop diseases have stopped.

Gary Lesoing, Extension Educator in Nemaha County: Soil moisture isn’t as bad here. We’ve had cool temperatures, some cloudy days and rain. Things are looking good. Conditions were ideal for corn pollination. As temperatures warm up, crop conditions could change rapidly. A lot of corn fields were sprayed for gray leaf spot, but overall corn in pretty good shape. We haven’t seen any aphids yet in soybeans. We’ve been checking our soybean sentinel plots and are seeing increasing bean leaf beetle numbers, but no aphids.

Teshome Regassa, Extension Educator, Crop Variety Testing: Results from our wheat variety trials are coming in and being analyzed and posted to the Variety Trials Web site. Our corn is looking great.

Robert Wright, Extension Entomologist: We’re getting reports of grasshopper problems from across the state, but particularly in the Panhandle and southwest Nebraska where they’re pretty abundant. Tom Hunt and I have a grant from the Nebraska Soybean Board to monitor stinkbugs in Lancaster, Saunders and Clay counties. We're seeing pretty good numbers of bean leaf beetles. Between bean leaf beetles and the grasshoppers, some fields are pretty chewed up, even if they’re not at economic levels yet.

Jim Schneider, Extension Educator in Hamilton County: Dryland fields are holding their own, but another rain would help. Irrigated yields are looking pretty good and we had good weather for pollination. Crop water use was low at around 1.2 inches for last week. Approximately 80% of the corn has been sprayed with fungicide for gray leaf spot. Some common rust has been observed, but no southern rust has been found. In general, corn is tall this year so there is some extra concern about keeping the stalks healthy to avoid lodging this fall. Leafminers have been bad this year. In cases where residual insecticide was applied with the fungicide in the presence of corn borer, it seems to have slowed them from damaging the ear leaf and higher leaves. A few soybean aphids are now showing up and a few scattered soybean fields have been treated for bean leaf beetle.

Ron Seymour, Extension Educator in Adams County: Field corn is generally in the milk stage of development. Most irrigated fields are in excellent condition. Grey leaf spot was commonly found on plants up to the ear leaf. Corn blotch leafminer damage was noticed in some fields up to the ear leaf with enough damage on lower leaves to cause the leaves to die.

Soybeans are in the early stages of pod fill. Most irrigated fields are in excellent condition. We've seen some brown spot and some minor defoliation. The common defoliators were bean leaf beetles, grasshoppers, and blister beetles. A few brown stink bugs were found.

Alfalfa fields are in fair to excellent condition depending on how much moisture they have received. Pest issues are minimal but pea aphids, green stink bugs, and velvet bean caterpillars were commonly found. Grain sorghum is in the late whorl stage. Most fields look good. A few green bugs and corn leaf aphids were found but infestations were minimal. Pastures are in fair to good condition depending on the amount of grazing and moisture received. The soil moisture conditions are generally dry with little moisture in the top 2 feet.