Oklahoma panhandle corn performance trials, 2006

              OKLAHOMA PANHANDLE CORN
ERFORMANCE TRIALS, 2006
PRODUCTION TECHNOLOGY CROPS
AHOMA COOPERATIVE EXTENSION SERVICE
DEPARTMENT OF PLANT AND SOIL SCIENCES
DIVISION OF AGRICULTURAL SCIENCES & NATURAL RESOURCES
OKLAHOMA STATE UNIVERSITY
PT 2006-12 November 2006 Vol. 18, No.12
Rick Kochenower Britt Hicks
Area Research and Extension Specialist Area Extension Livestock Specialist
Plant and Soil Sciences Department Northwest District
TRIAL OBJECTIVES AND PROCEDURES
Each year the Oklahoma Cooperative Extension Service conducts corn performance trials in the Oklahoma panhandle. These trials provide producers, extension educators, industry representatives, and researchers with information on corn hybrids marketed in Oklahoma. Company participation was voluntary, so some hybrids marketed in Oklahoma were not included in the test. Company or brand name, entry designation, plant characteristics, and maturity information, were provided by the companies and was not validated by OSU; therefore, we strongly recommend consulting company representatives for more detailed information regarding these traits and disease resistance ratings (Table 2).
Irrigated test plots were established at the Oklahoma Panhandle Research and Extension Center (OPREC), near Goodwell and the Joe Webb farm, near Guymon. Fertility levels, herbicide use, and soil series (when available) are listed with data. Trials were two 25-foot rows seeded at a target population of 32,000 plants/ac. Plots were trimmed to 20 feet prior to being harvested to determine grain yield. The ensilage trial was seeded the same as grain trial with 10 feet of one row harvested to determine yield. The experimental design was a randomized complete block with four replications. Grain yields are reported consistent with U.S. No. 1 grade corn i.e. 56 lbs/bu and adjusted to moisture content of 15.5%. Corn ensilage was harvested at the early dent stage with average moisture content of 65.3% and production is reported as tons/ac adjusted to 65% moisture.
GROWING CONDITIONS
The planting period was characterized by a lack of soil moisture due to inadequate rainfall received throughout the winter and spring. Most producers used pre-irrigation to obtain desired surface and subsoil moisture levels. Soil temperature of 61° F on April 1 at the two-inch depth was consistent with observations in previous years. During the growing season rainfall was below the long-term average from April through late July (Table 1), but rainfall in late July and August reduced late season irrigation when compared to 2005. Rainfall at OPREC (10.88 inches) was less than most locations in the panhandle, with rainfall amounts east of Guymon totaling near 19 inches from late June through August. The panhandle region had several yield reducing hailstorms from mid May until early July. The hailstorms in May led to some acres being replanted. OPREC received two hail and windstorms in June which dramatically reduced the yield for corn planted around April 10 (Fig. 1). This is in contrast to previous years data from the planting date experiment, as the highest yields in the previous 6 years were obtained on the April 10 planting date. High moisture corn was cut with short delays due to rainfall in late August and early September, but there were no major delays for dry corn harvested from mid September to mid October.
RESULTS
Grain yield, test weight, harvest moisture, and plant populations for OPREC and Webb trials are presented (Tables 3-4). Ensilage yields are reported in Table 5. Acid Detergent Fiber (ADF) and Total Digestible Nutrients (TDN), however are not reported, because no significant differences existed among hybrids. Averages were 33.4, and 64.0%, for ADF and TDN respectively. Similarly, there were no differences among hybrids in net energy values for maintenance, lactation,