Entries. Several seed companies that sell sunflowers were contacted in early 2001 and asked to provide 1 or 2 of their own Nu-Sun varieties they thought would perform best in the Missouri region. Three conventional varieties that performed well in the Missouri 2000 trial were also included. Ten varieties were tested in this comparison, 7 NuSun and 3 conventional hybrids.
Locations. Sunflowers were grown at two locations in Missouri and one location in Arkansas. All locations were on University research farms. The locations and the planting dates were:
Field Plot Design. Each test was arranged in a Randomized plot design with four replications. All plots were four rows wide and 20 feet long. The between-row spacing was 30 inches at all locations. Only the center two rows were harvested to determine yield.
Plot Management. The tests were planted and harvested with equipment designed for small-plot work. Fertilizer was applied at each site at the discretion of the farmer. Herbicides and cultivation were used for weed control and plots were hand weeded as necessary. Management details varied from location to location and are specified on individual yield tables.
Data Recorded. Maturity dates were recorded at 50% flowering. Total seed weights were taken from the two center rows of each plot at harvest. In addition to yield, lodging, population, grain moisture, and plant height were measured at harvest in all trials. All yield data are presented on a pound per acre basis of air dried seed at 10 percent moisture.
Oil Analysis. Seeds were collected from all locations for use in oil analysis. Samples of greater than 25 g were taken from each harvested replication and pooled together for a given variety in that planting. Samples were further machine cleaned with air and screening. These samples were submitted to the USDA-ARS Northern Crop Science Lab for analysis. The oil percent is reported on a 10% moisture basis. The oleic acid content is reported as a % of the oil.
The Nu-Sun trait that accounts for the elevated oleic acid composition is dominant. The Nu-Sun and conventional variety plots were not separated and Nu-Sun varieties were used for border rows. Therefore, the oleic acid composition would be expected to be higher than normal and/or subject to greater variability in the conventional varieties. However, the oleic acid expression by a given Nu-Sun variety in these trials is likely to be accurate.
Electronic Accessibility of Data. Results of the Missouri Sunflower Performance Trials are now available online at http://agebb.missouri.edu/cropperf/sunflower/. If you need assistance in accessing the data on the web call 573/882-4827 for the system staff's help.
Agricultural Experiment Station