Author
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Darrah, Larry |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 9/20/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Corn stalk lodging continues to be a barrier to increased maize productivity, accounting for 5 to 25 % annual yield losses. Lodging counts, even over several locations, provide relativelypoor data for making selections to improve standability. This presentation contrasts the effectiveness of stalk crushing strength and rind penetrometer resistance for improvement of stalk strength. Stalk crushing strength is a destructive measure, with sampling usually 2-3 wk after flowering. Equipment costs are in excess of $7500. Steps include harvesting of the second internode above ground level, drying stalk samples for 6-8 wk, cutting of 5 cm sections from the internode, and crushing sections vertically in a hydraulic press. Separate plantings are needed for crushing strength and yield data. Rind penetrometer resistance is non-destructively sampled in the internode below the ear and uses equipment costing under $800. Effective selection can be done just before flowering permitting recombination of selected plants or progenies. Average direct gain in stalk crushing strength from six cycles of selection in two populations was 8.6%/cycle, whereas gain in stalk crushing strength in a single population selected by rind penetrometer resistance was 7.2%/cycle. Direct response to rind penetrometer selection was 8.0%/cycle. Favorable correlated responses to rind penetrometer selection were obtained for stalk crushing strength, stalk lodging, vertical root pulling resistance, root lodging, and ear height. Grain yield did not show a correlated response. |
