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Hybrid selection for reducing herbicide rates in corn
Abstract
Modern corn hybrids exhibit differences in plant height and size, leaf area index, and leaf angle. This study was conducted to determine the interaction of modern corn hybrids with reduced rates of preemergent herbicide in combination with interrow cultivation on control of velvetleaf (Abutilon theophrasti Medic.) and foxtail (Setaria faberi L.), weed seed production, and corn growth and grain yield. Six corn (Zea mays L.) hybrids and four rates of herbicide application in combination with interrow cultivation were studied at Mead, NE. Corn grain yield differences among hybrids up to 3.0 Mg ha$\sp{-1}$ occurred in three of four years, yet similar relative declines in grain yield occurred as herbicide rate decreased or without cultivation. Kernels per ear, ears per m$\sp2$, and kernel weight were all correlated with grain yield (r = 0.73, 0.54, 0.30 in 1993-94; r = 0.69, 0.51, and 0.37 in 1991-92, respectively). Hybrid yield differences did not influence yield component association with grain yield indicating grain yield and yield component stability of modern hybrids to weed competition. Growth analysis of corn height, leaf area index, specific leaf area, and plant dry matter accumulation did not clearly correlate to corn grain yield variability caused by weed competition. Corn hybrid differences in suppression of weed growth and seed production occurred in 1993 and 1994, but were not consistent. Plots with the very tall, erect-leaf hybrid contained 7.4 velvetleaf m$\sp{-2}$ versus 8.6 to 10.1 velvetleaf m$\sp{-2}$ in plots with other hybrids. They also had the lowest velvetleaf seed production of 23 100 seeds m$\sp{-2}$ versus 25 100 to 30 700 seeds m$\sp{-2}$ for other plots. Erect-leaf hybrids also showed weed suppressive capabilities compared to horizontal-leaf hybrids in 1993 and 1994. Corn hybrid ability to reduce weed populations and seed production was less than cultivation or herbicide application in this study. Hybrid selection as a tool in an integrated weed management program will have minimal or inconsistent influence on weed suppression.
Subject Area
Agronomy|Plant propagation
Recommended Citation
Roggenkamp, Gregory J, "Hybrid selection for reducing herbicide rates in corn" (1997). ETD collection for University of Nebraska-Lincoln. AAI9734638.
https://digitalcommons.unl.edu/dissertations/AAI9734638