Submitted to: Weed Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/1/2008
Publication Date: 9/10/2008
Citation: Bryson, C.T., Reddy, K.N., Burke, I.C. 2008. Morphological Comparison of Morningglory (Ipomoea and Jacquemontia spp.) populations from the Southeastern United States. Weed Science 56:692-698. Interpretive Summary: Morningglories are among the most troublesome weeds in southern agriculture. Recently variable glyphosate susceptibility was reported among pitted morningglory populations. Research determined pitted morningglory, sharppod morningglory and a hybrid between pitted and sharppod morningglories possessed highly variable morphological characteristics. Baseline morphological information is reported for 76 accessions including nine morningglory species form six southern states. The database will be used in future research to determine if differential morphology and herbicide susceptibility are correlated. If correlated, recommendations can be modified to achieve maximum control based on morningglory morphology.
Technical Abstract: Morningglories are among the most troublesome weeds in row crops and other agricultural areas throughout the United States. Plants of pitted morningglory, sharppod morningglory, and a fertile purported hybrid between pitted and sharppod morningglory (hybrid morningglory), were compared with cypressvine, ivyleaf, palmleaf, purple moonflower, red, and smallflower morningglories in greenhouse studies at Stoneville, MS. Plants from each of 76 accessions were evaluated for pubescence, corolla size and color, sepal shape, and other morphological traits with the goal to develop baseline data to correlate with herbicide sensitivity and herbicide tolerance/resistance issues. Among these morningglories, the most diverse traits were pubescence and flower characteristics. Greatest morphological diversity was among hybrid morningglory accessions as characteristics were intermediate to pitted morningglory and sharppod morningglory accessions. Corolla color was white (90%) or white with faint pink veins (10%) in pitted morningglory, lavender (100%) in sharppod morningglory, and varied from pinkish lavender (45%), lavender (38%), white (12%), to white with pink veins (5%) in hybrid morningglory accessions. Pitted morningglory corolla diameters were not only smaller but less variable in size than hybrid, sharppod, and other morningglory accessions. Corolla diameter and lengths were most variable in sharppod morningglory accessions when compared to other morningglory species. The sepal tip shape was broadest (broadly acute to obtuse) in palmleaf and sharppod than in hybrid, pitted, or other morningglories (acute to narrowly acute). In future studies, these morphological traits will be compared to determine if any are correlated with glyphosate sensitivity.