This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Baur, J. R. Articles by Morgan, P. W. Search for Related Content PubMed PubMed Citation Articles by Baur, J. R. Articles by Morgan, P. W. Agricola Articles by Baur, J. R. Articles by Morgan, P. W.

Articles

Effects of Picloram and Ethylene on Leaf Movement in Huisache and Mesquite Seedlings ^1,2

^a Departments of Range Science and Plant Sciences, Texas A&M University, College Station, Texas 77843

Application of 4-amino-3,5,6-trichloropicolinic acid (picloram) to roots stimulated the production of ethylene in both mesquite [Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell] and huisache [Acacia farnesiana (L.) Willd.] seedlings. Herbicide levels rose in tissues before we detected increased ethylene production. Rates of ethylene production by various parts of the plant paralleled herbicide concentrations. In both species, picloram caused loss of leaf movement and epinastic curvature of leaves and stems. Only huisache was defoliated by picloram. Rates of ethylene production increased before we observed any leaf movement or defoliation responses. Fumigation of plants with levels of ethylene, calculated to approximate those in herbicide-treated plants at the initial loss of leaf movement, caused the same symptoms as picloram treatment. The time sequence of ethylene fumigation and loss of the ability for leaf movement is compatible with the hypothesis that there is a causal relationship between picloram and ethylene production and loss of leaf movement.

² Preliminary reports of this study appear in Proceedings 22nd Annual Meeting, Southern Weed Conference, 1969 and Proceedings of 66th Annual Meeting, Association of Southern Agricultural Workers, 1969 (Southern Section, American Society of Plant Physiologists).