CORN
Crop Observation and Recommendation Network

August 11-17, 2003
C.O.R.N. 2003-26

In This Issue:

A) Soybean Aphid and Bean Leaf Beetle Updates
B) Slugs in Late-Summer Planted Crops
C) Continue to Check for Potato Leafhopper in Alfalfa
D) Potential Ergot Problems in Hay
E) Tri-County Field Day This Month

A) Soybean Aphid and Bean Leaf Beetle Updates - Hammond & Eisley CORN Questions

Reports have come in over the past two weeks of soybean aphid being found in many fields in Ohio. The majority of these reports indicate low to moderate populations of aphids, between 50-100 per plant, although many indicate populations approaching or reaching threshold. Reports of fields being treated are also being received. Aphids are still be on the increase, which is important because many late planted soybean fields are still in the late flowering and early pod developmental stages. Growers are advised to continue to monitor the situation in their fields and take action if necessary.

Additionally, bean leaf beetles continue to feed on soybeans in many parts of the state. Populations range from low to moderate, with a few reaching high numbers. One field averaged over 150 per 10 sweep sample, which is over 15 beetles per single sweep; numerous fields averaging over 50 per 10 sweeps are being found. As with the soybean aphid and other defoliators, growers are advised to scout their fields. As mentioned in earlier CORN articles, knowing you have a large population of bean leaf beetles now will help you make appropriate management decisions later in the summer when the next generation begins to feed on pods.

B) Slugs in Late-Summer Planted Crops - Hammond & Eisley CORN Questions

We received a report from western New York of dry beans, recently planted in a no-till situation, being severely injured by slugs. Because of significant rainfall and cool summer temperatures, the slugs had apparently remained active during the summer. This reminded us of a situation three years ago of a double-cropped soybean field in northwest Ohio planted no-till into wheat stubble that had a significant stand reduction because of slugs. Because of the significant rainfall and relatively cool temperatures that Ohio has experienced the past few months, the possibility exists, however slight, of slug injury to those crops being planted into no-till situations. Crops possibly affected include double-cropped soybeans and fall-planted alfalfa, among others. Growers who have recently or will be planting in no-till situations should be aware of potential problems and scout their fields. Treatment might be required in situations where large slug populations exist.

C) Continue to Check for Potato Leafhopper in Alfalfa - Eisley & Hammond CORN Questions

Potato leafhopper (PLH) populations normally will decline significantly at this time of year. However, populations remain high in many alfalfa fields (especially those that need to be cut). We would recommend that sweeps for PLH continue in alfalfa until the populations decline and those fields that will be harvested this week should be checked in 7 to 10 days to see if the populations have declined. An August treatment is needed some years for PLH.

D) Potential Ergot Problems in Hay - Lipps CORN Questions

With the overwhelming wet weather and the delay in making hay this season, the potential for having ergot in the grasses cut for hay is quite high. This may not be a widespread problem but hay producers should be on the look out for ergot. Ergot is serious business and hay producers should be aware of the possibility of this disease in forage grasses and be ready to protect their hay clients from feeding problems. Ergot is a fungal disease of grasses and although it does not cause serious damage to the plant, it produces enlarged black fungal bodies (sclerotia) in the grass heads. These bodies are commonly called 'ergots'. The ergots contain alkaloids that cause problems when eaten. Even feeding small amounts over a period of time can cause significant problems. Common symptoms can include abortion, sloughing of skin, gangrene, and hallucination. In horses it can cause severe founder, hoof damage and lameness.

At this time the best thing to do is for the hay producers to inspect fields before they cut the fields. Generally ergot is found around the headlands and edges of the fields, but fields left in hay for a long period of time (especially grass hay or fields with weed grasses) can have ergot scattered throughout the field. It is suggested that headlands and areas with visible ergot in grass heads be mowed, but not be removed from the fields as hay. Obviously this can only be done if the field was scouted first.

It is very difficult for the hay buyer to see ergot in hay bales, especially if the incidence of the disease is relatively low. However, if there is a lot of ergot, then it may be possible to see the enlarged black ergots in the grass heads within the bale. Concerned hay buyers can break open bales and inspect the grass heads for ergot. Although it is impossible to check every bale prior to purchase, grasses in bales can be inspected as the hay is fed.

Fields with substantial levels of ergot should be plowed at the end of the season to bury all hay residues, including the ergot, at least 3 inches deep. Next spring plant soybeans or corn (not a forage grass) without disturbing the soil or uncovering the hay residue. Keep the field in these crops for at least three years before planting forage grasses again to allow sufficient time for soil bacteria to decompose the ergots. Not all ergots will be eliminated but the population should be reduced to lower the potential for ergot to occur again. To prevent further problems control grassy weeds in all rotation crops and each year mow the headlands and grass waterways to prevent the grasses from producing heads during the summer.

E) Tri-County Field Day This Month - Siegrist CORN Questions

The Tri-County Agronomy Day is headquartered this year at the David Miller farm near Millersport in Fairfield County on August 21. The meeting will provide information for commercial grain producers and a continuing education opportunity for Certified Crop Advisors. This year's program will run from 1 p.m. until 8 p.m. with a meal included. Cost is $5.00 for the program with no advance registration.

This year's program will feature the Farm Journal Magazine field agronomist, Ken Ferrie who will address assessing stand uniformity and yields. He will also present data on fertilizer starter programs in corn production.

Additional programs will be offered on soybean aphid, cash forage production, soil porosity and aeration, and GPS auto guidance systems. CCA continuing education credits of 0.5 SW, 2.0 CM and 0.5 NM will be offered. Additional information and a map are available by phoning (740) 349-6900 or on the Web Site: http://licking.osu.edu. The program is sponsored by OSU Extension, SWCD and NRCS in Fairfield, Perry and Licking Counties.

Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.

Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/

C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.

Editor: Harold Watters        Web Editor: Nathan Watermeier

Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.

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