Author
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Darrah, Larry |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 10/3/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Despite breeders' efforts, stalk lodging still causes 5 to 25% yield loss in maize (Zea mays L.). The occurrence of stalk lodging has been increased by practices of using high-yielding cultivars, high nitrogen fertility rates, and high plant density. Lodging resistance as characterized by resistance to stalk breakage and root lodging continues to be a major breeder objective. This paper summarizes direct and indirect gains from two studies involving selection by using a modified electronic rind penetrometer in MoSCSSS. For rind penetrometer selection, the internode below the top ear attachment node was probed. From about 600 competitive plants, 120 selected S0 plants were recombined using bulked pollen. By measuring rind penetrometer resistance before flowering, recombination of selected plants is done in the same season completing one cycle of selection per crop season. Direct gain from rind penetrometer resistance selection was high, averaging 8.8%/cycle. Indirect gains in stalk crushin strength resulting from rind penetrometer resistance selection were almost twice that from direct selection for stalk crushing strength in the second expanded internode above the ground (average 8.6%/year for rind penetrometer resistance selection vs. 4.8%/year for stalk crushing strength selection). In contrast to results from stalk crushing strength, we found favorable indirect responses to selection for ear height (reduced), days to flower (slightly reduced), and yield (no change in the population per se with an increase shown in the Mo17 topcross). |
