The LaRue County Extension Service conducts corn and soybean variety plots annually in cooperation with a local farmer and participating grain dealers. For the third year, the cooperator was Carlos Tucker on the Duel Creekside Farm. Seed companies supply seed, assist at planting and harvest and sponsor a field day.
Farmers use the yield information, along with other plot data and information, to help decide which varieties to grow next year. Each company was permitted to enter two varieties of both corn and soybeans.
The corn plots were planted April 25 no-till in a Nolin soil where soybeans were the previous crop. It was planted in 30-inch rows at 27,000 seeds per acre. Varieties were planted by maturity dates.
Harvest date was Oct. 7. The field suffered considerable drought stress, and yields averaged more than 40 bushels per acre less than last year at 120.4 bushels per acre. Yields were calculated to 15.5 percent moisture. A check variety was planted at each end and in the middle of the plot. Yield rankings were determined by adjusted yields that were calculated by a formula utilizing yield variation in yield of two nearest checks from the average of the three check plots.
The check variety, NK Brand N68-B8 averaged 123.0 bushels per acre.
The top variety, DeKalb DKC 61-69 VT3 had an adjusted yield of 143.9 bushels per acre, next was Garst 84U94 CB-LL-RW with an adjusted yield of 135.1 bushels.
Other rankings (by adjusted yield) were Crow’s 4846T, AgriGold A6479 VT3, Pioneer 33F85, Vigoro V5273 VT3, DeKalb DKC 63-42 (VT3), Crow’s 5304 VT3, Wyffels W9121 PP, AgriGold A6633 VT3, Garst 8353 CB LL, AgVenture 8036 V3R, AgVenture R9146 VBW, NK Brand N72-Q6, NK Brand N77P -3000GT, Exsegen ES518, Southern States 738, Vigoro V5474 VT3, Southern States 647 VT3, Wyffel’s W7381, Pioneer 31P41, and Exsegen ES414.
The soybean plot was planted on May 7 and harvested on Oct. 23. All varieties were Roundup Ready Group III or IV. The field was planted no-till following corn in Nolin soil. The beans were planted in 7.5-inch rows by doubling back with a 30 inch row planter. Planting rate was approximately 180,000 seeds per acre.
Herbicides used included Extreme as a burndown and Buccaneer and FirstRate after planting.
The yields were low due to drought stress with 25 bushels less per acre than last year with 37.2.7 bushels per acre. Yields were adjusted to 13% moisture. Last year’s winner, AgVenture AV47G7 NRR STS was the check variety and averaged 38.1 bushels per acre.
Actual yields were calculated and then adjusted yields, using the method described above for corn. Ranking was done by adjusted yield. The top yielding variety was Asgrow 4703 with an adjusted yield of 40.3 bushels per acre, followed by Agrow 3705 with 39.7 bushels per acre, and Garst S46U6 at 38.8 bushels per acre.
Other varieties (in order by adjusted yield) were: Crow’s 4517R, AgVenture 44X1 RR, NK Brand S44-D5, Southern Cross Eli, Pioneer 94Y70, Garst S39-A3, Pioneer 94Y20, Vigoro V48N7RS, Crow’s 3916, Southern States RT 385, Vigoro V40N8RS, Southern Cross Michael, Southern States 3951, and AgVenture 39X1RR.
Complete results of both tests are available at the Extension Service office. The reports also list yields by actual yield, field location, and multiple year data.
The 2008 UK State Corn Variety Plot publication is also available (soybean is not available yet). Call the office at 358-3401 to request copies, stop by and pick up a copy or download at the UK grain Web site.
To simplify information, trade names have been used. No endorsement is intended, nor criticism implied, of products not named.