Soybean Production Research,
  Tips, and Crayons

"Roundup Ready" Soybean Performance

The first independent, unbiased variety performance tests for Roundup Ready soybeans were conducted in Wisconsin at three locations (Arlington, Janesville, and Racine) in 1997. Twenty-one varieties were entered from eight different companies. Yields ranged from 52 to 63 bushels per acre with an average of 59. Once again, this underscores the importance of not choosing varieties based solely on an individual trait. There are top performing varieties and some "also rans". Use the same selection criteria for the Roundup Ready varieties that you would for conventional ones. Interestingly, the 125 conventional varieties tested at three Roundup Ready sites also averaged 59 bushels per acre with the top five varieties averaging about 5 bushels per acre more than the top 5 Roundup Ready entries (65.8 vs. 61.6 bushels per acre).

"Roundup Ready" clearly offers producers a unique opportunity to control certain species of weeds. The technology may be especially useful in no-till systems for those pesky perennials. Another potential advantage to Roundup Ready is that there is virtually no risk of crop injury (and perhaps subsequent yield reductions??) from the herbicide application. Already we're seeing price reductions on certain conventional soybean herbicides to compete with the reduced weed control costs of using Roundup. When evaluating your soybean inputs, consider ALL costs (seed and herbicide) as well as potential returns (variety performance).

Soybean Seeding Rate Recommendations

The following link constitutes University of Wisconsin soybean seeding rate recommendations based on extensive research over the past 10 years. Note differences for row spacing and tillage (residue) variables.

Wisconsin Soybean Seeding Rate Recommendations

White Mold a Problem in 1997....again!!

It's getting to the point where the "taking my chances" strategy with sclerotinia, or white mold as it is usually called, is becoming a costly one. White mold was widely seen throughout Wisconsin and in Fond du Lac County soybean fields in 1997. Although the list of factors that influence white mold is lengthy, realistically there really is only one major defense for most soybean growers ----- variety selection. That is of course unless you're willing to make a major management change in tillage practices or row spacing just to manage one disease at the expense of giving-up production for other reasons.

At Galesville and Hancock, two locations in the 1997 UW variety tests with intense white mold pressure, incidence of white mold ranged from 5 to 65 percent across 93 varieties. How much did this impact yield? The variety with 5 percent infection averaged 51 bushels per acre compared to the 65 percent infected variety with a yield of only 29 bushels. Unless you are planting a first-year field of soybeans, white mold tolerance/resistance simply MUST be a component of your selection criteria. The best place to get this information is from the UW Soybean Variety Performance Bulletin.

Phytophthora Root Rot More Prevalent

Like white mold, phytophthora root rot seems to be easier to find in area soybean fields with each passing year. In 1997, some fields suffered yield reductions of nearly 50 percent from a combination of early and late phytophthora infections. These yield infections did not just occur in low, wet areas but also on fields that would be considered well drained. The easy explanation is that soybean acreage has increased dramatically in the past ten years with more fields now having long histories of soybean production. It appears that disease organism populations are also building in many of these fields. Once again, when making variety selections, don't overlook phytophthora gene resistance (compared to only tolerance) as a component of the performance package. For maximum protection, focus on those varieties with Rps 1k gene resistance. Once again, this information is available from the UW Soybean Variety Performance Bulletin.

The Color of Soybeans

Want to support the soybean market and keep your kids or grandchildren happy at the same time? Soybeans have now found their way into children's crayons and are being marketed locally under the Prang label. You can't miss them ------- "MADE FROM SOYBEANS" is right on the front of the box.