Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 29, 2006
Publication Date: January 12, 2007
Citation: So, Y.F., Pataky, J.K., Williams, M., Davis, A.S. 2007. Role of sweet corn canopy architecture in crop/weed interactions. North Central Weed Science Society US Proceedings. 61(1):166. Technical Abstract: : Sweet corn canopy architecture influences crop tolerance (CT) to weed interference and the crop’s suppressive ability (WSA) of weed growth and fecundity. A quantitative analysis of specific traits responsible for CT and WSA could enhance the impact of hybrid characteristics on weed management in sweet corn. Twenty three sweet corn hybrids from nine seed companies were grown in the presence and absence of wild proso millet in Urbana, Illinois in 2006. Inclusion of hybrids was based on a priori qualitative observations of variation in canopy architecture and stress tolerance. Several canopy morphological and phenological traits were characterized from crop emergence to harvest. Crop tolerance to weed interference was determined as weed-free ear mass or ear number as a percentage of weedy yield. At the time of crop harvest, WSA was determined for wild proso millet biomass and fecundity as the inverse of weed response within a hybrid to weedy monoculture response. Significant variation among hybrids was observed for most CT, WSA, and canopy traits. Positive correlations ranging from 0.22 to 0.34 (P < 0.05) were observed between CT and WSA traits, indicating that hybrids with high CT also tend to have high WSA. Sixteen of 18 canopy traits were associated with CT and WSA traits. Several traits that describe late-season canopy were positively associated with CT traits, including late-season height, late-season light interception, leaf area near anthesis, shoot biomass near anthesis, time to silk emergence, and time to harvest. Several traits that characterize early canopy development were positively associated with WSA traits, including seedling vigor, upright leaf angle, early-season light interception, and early-season LAI. Differences in CT and WSA among the hybrids and their significant correlations to canopy growth and development lead us to hypothesize that certain crop traits could be used as indicators of CT and WSA among hybrids. Traits that are associated with late-season canopy morphology appear to provide information on CT, while traits that are associated with early canopy development are useful for describing WSA. Based on these results, we hypothesize that both early development of the crop canopy and final canopy architecture contribute to hybrid effects on crop/weed interactions.