SOYBEAN VARIETY YIELD TEST IN 1999
Department of Crop & Soil Sciences
The annual testing of Roundup Ready and non-Roundup Ready varieties and experimental lines of soybeans was conducted at four locations in New York State in 1999. At each location we planted all entries of the same maturity Group in a separate test. Also, Roundup Ready, non-Roundup Ready, and food grade varieties were evaluated in separate tests. Each individual plot at Canton and Chazy consisted of four 20-foot rows spaced 14 inches apart. There were four replications of each entry at each location. We used preemergence applications of herbicides in the non-Roundup Ready tests, whereas we relied exclusively on 3 pints/acre of Roundup Ultra for weed control in the Roundup Ready tests.
During the season, notes on development were made at intervals. Yields were determined by harvesting a measured section of the center rows in each plot. All plots were harvested with a Hege plot combine.
Both sites were exceptionally warm but much wetter than most regions in the state during June and July (Table 1). Both sites, however, did dry out during August. Consequently, soybean yields at the Canton site, which had a somewhat droughty soil, were exceptionally low because of the dry August conditions (Table 2). In contrast, yields were exceptionally high at the Chazy site, which has a deep soil with high water holding capacity (Table 2).
When averaged across sites, Sentry, a Group 0 variety, yielded the greatest among Group 0 varieties. Sentry, however, yielded much more than the other varieties at the high-yielding Chazy site but similarly as the other varieties in the low-yielding Canton environment. Evidently, Sentry does not have as great a yield stability as some leading varieties have shown in recent years. Nevertheless, Sentry, which averaged 3 to 7 bu/acre more in yield than other Group 0 varieties, yielded about 10 bu/acre more at Chazy compared with other varieties, except for Telstar. As in the past, the Group I varieties offered no yield advantage compared with the Group 0 varieties at Canton and Chazy. AG 1301 yielded the most in the Roundup Ready trial at Canton and the same as the other Roundup Ready varieties at Chazy. Overall, the Roundup Ready varieties yielded as well as the non-Roundup Ready varieties at both sites.
Table 1. Monthly and total precipitation and growing degree days (86-50° system) at Canton and Chazy in New York in 1999.
Table 2. Soybean yields, height, lodging, and physiological maturity of early, medium, and Roundup Ready soybean varieties at Canton, and Chazy, New York in 1999.