Results of variety trials for soft red winter wheat grown in seven locations across Missouri are now available on the Internet from the University of Missouri.

The statewide yield average was 55.7 bushels per acre, down 6.6 bushels from 2001 yields. The average was down 15.3 bushels from record-setting 63 bushels per acre in 1997.

Yields in the official variety comparisons reflect the many problems with weather and disease faced by wheat farmers this year, said Anne McKendry, MU wheat breeder who conducts the annual tests.

Missouri test locations were Charleston and Portageville in the Bootheel; Lamar and Mount Vernon in the southwest area; Trenton and Novelty in north Missouri and Columbia.

Complete results from every site can be seen on the MU Agricultural Electronic Bulletin Board. The Web address is: http://agebb.missouri.edu/cropperf/. Printed books are available at University Outreach and Extension centers in each county.

The best yield average at an individual site was 75 bushels per acre at Trenton. The lowest average was at Lamar with 39 bushels. The two southeastern locations together averaged 58.5 bushels.

The winter weather was milder than usual with little snow cover. Early crop reports coming out of the winter indicated a possible record-breaking state yield.

However, spring weather was not good for wheat, McKendry said. Temperatures dropped into the single digits and low teens, causing frost damage. Temperatures, overall, averaged 3 to 4 degrees below normal statewide. May was the second wettest month on record with up to twice the normal rainfall.

“Rain and high humidity when the wheat is flowering encourages Fusarium fungus, or scab, in the seed heads,” McKendry said. Scab reduces yields and results in lighter test weight, or pounds per bushel.

Test weight is an important buying criterion for millers.

Barley yellow dwarf, a disease spread by aphids eating on the plants in the fall, also reduced wheat yields. The disease causes wheat leaves to turn yellow at the time the wheat heads are filling. Reduced chlorophyll in the leaves cuts the efficiency of plant growth.

“The warm, dry weather in the fall and the mild winter may have contributed to the barley yellow dwarf,” McKendry said.

Other diseases, including wheat streak mosaic virus and stripe rust, also hit the growing plants in some locations.

A year of heavy disease pressures helps separate out the best varieties, McKendry said.

The top-yielding variety in the statewide test was an experimental variety being developed at MU. Scab resistance is among its main features. The variety, currently known as MO 980725, averaged 64.3 bushels per acre statewide and more than 80 bushels per acre in the test at Trenton.

Five commercial varieties produced results that were slightly lower but not statistically different from the top-yielding variety. They are: Excel 400, MFA Brand 766, Lewis 864, MFA Brand 1828, and MFA Brand 766. Two other MU experimental lines also were in the top group.

McKendry said that two of the MU lines possibly would be named and released to foundation growers in the Missouri Seed Improvement Association this fall. Seed will be not be available to certified growers until 2003.

Wheat breeders from other states also enter newly developed lines in the state variety trial. Most of the entries come from commercial seed companies that pay fees to finance the testing program.

The MU variety trials give wheat farmers an unbiased source of information to use in selecting seed for planting this year. Winter wheat is seeded in the fall, usually in September, and harvested the following year, usually in late June or early July.

Producers using the tests often look first at the yield, McKendry said. But other factors should also be considered in selecting a variety to plant.

The published report shows ratings on disease, winter survival, lodging (falling over), plant height, heading date, test weight and grain moisture content.

Producers using the results should look first at the results from plots nearest to their location, McKendry said.

Because of budget cutbacks this year, copies of the variety trial book will not be mailed to wheat growers in the state. Main distribution will be through the Internet. Printed copies can be obtained at the Extension offices or from MU Extension Publications at 800-292-0969.