Oklahoma corn performance trials, 2011

              OKLAHOMA CORN PERFORMANCE TRIALS, 2011
PRODUCTION TECHNOLOGY CROPS
OKLAHOMA COOPERATIVE EXTENSION SERVICE
DEPARTMENT OF PLANT AND SOIL SCIENCES
DIVISION OF AGRICULTURAL SCIENCES & NATURAL RESOURCES
OKLAHOMA STATE UNIVERSITY
PT 2011-9 December 2011 Vol. 23, No. 9
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 Oklahoma. 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 were not validated by OSU; therefore, we strongly recommend consulting company representatives for more detailed information regarding these traits and disease resistance ratings (Table 1).
Irrigated test plots were established at the Oklahoma Panhandle Research and Extension Center (OPREC) near Goodwell and the Joe Webb farm near Guymon. Three rainfed trials were also planted in north central Oklahoma but due to drought they were not harvested. Fertility levels, herbicide use, and soil series (when available) are listed with data. Individual plots were two 25-foot rows seeded at a target population of 32,000 plants/ac at the Joe Webb location and silage trial at OPREC. Due to more limited irrigation at OPREC the grain trial was seeded at a target population of 28,000 plants/ac. Plots were trimmed to 20 feet prior to being harvested to determine grain yield. The ensilage trial was seeded the same as the grain trial with 10 feet of one row harvested to determine yield. Experimental design for all locations was a randomized complete block with four replications. Grain yield is reported consistent with U.S. No. 1 grade corn (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 69% and production is reported as tons/ac adjusted to 65% moisture.
GROWING CONDITIONS
Drought affected corn state-wide. Corn planting started in early April and continued without interruption until completed for most producers. Pre-irrigation was required for irrigated corn in the panhandle for emergence due to lack of rainfall from September 2010 until planting. Many producers applied 5 to 7 inches of pre-irrigation, others applied enough for emergence and started sprinklers and never shut them off until August. Fluctuating air temperatures reduced soil temperatures and slowed emergence in April and early May (Fig. 1). Temperatures during the growing season ranged from cool in late April and early May to hot from late May till maturity in September. Corn yield was severely reduced on June 26th for most of the high plains when temperatures were above 110 degree F° with wind speeds above 30 mph. Corn leaves were turning gray from the heat and wind stress the next day. Corn that was planted on lower volume wells never recovered from this day. Rainfall for the period was below the long-term mean (Table 2). Irrigation well volume was the critical factor for the yields in the region. From conversations with producers grain yield for 500 gpm wells ranged from 0 to 90 bu/ac, 600 gpm well yields ranged from 90 to 140 bu/ac, and 700 gpm or higher yields ranged from 170 to 240 bu/ac. The harvest period had no major delays due to weather.