Fate of Prometryn in Prometryn-Tolerant and -Susceptible Cotton Cultivars

• Published in: Pesticide biochemistry and physiology Vol. 56; no. 2; pp. 111 - 122
• Main Authors: Waldrop, M.P., Sterling, T.M., Khan, R.A., Molin, W.T.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01-10-1996; Elsevier
• Subjects: ABSORCION; ABSORPTION; Biological and medical sciences; Chemical control; FISIOLOGIA VEGETAL; Fundamental and applied biological sciences. Psychology; GLANDE VEGETALE; GLANDULAS VEGETALES; GOSSYPIUM; GOSSYPIUM BARBADENSE; GOSSYPIUM HIRSUTUM; HERBICIDAS; HERBICIDE; HIPOCOTILOS; HYPOCOTYLE; METABOLISME; METABOLISMO; METABOLITE; METABOLITOS; Parasitic plants. Weeds; PHYSIOLOGIE VEGETALE; Phytopathology. Animal pests. Plant and forest protection; PROMETRINA; PROMETRYNE; RACINE; RAICES; RESISTANCE AUX PRODUITS CHIMIQUES; RESISTENCIA A PRODUCTOS QUIMICOS; VARIEDADES; VARIETE; Weeds; Malvaceae; Agricultural chemical product; Gossypium barbadense; Biochemistry; Fiber crop; Absorption; Hypocotyl; Dicotyledones; Angiospermae; Physiology; Intraspecific comparison; Pesticide resistance; Phytopharmacology; Plant tissue; Translocation; Root; Tolerance; Gland; Pesticide fate; Metabolism; Herbicide; Toxicokinetics; Photosynthetic system; Phytotoxicity; Sensitivity resistance; Triazine derivatives; Secretory tissue; Spermatophyta; Gossypium hirsutum; Prometryn; Cultivar; Concentration distribution
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1006/pest.1996.0065

Prometryn is a soil-applied herbicide used in cotton production; however, it can cause cotton injury. Our objective was to determine the mechanism of differential tolerance among cultivars as related to differences in prometryn absorption, translocation to photosynthetic tissue or lysigenous glands, and metabolism. The prometryn-tolerant cultivars, Pima S-7 (Gossypium barbadenseL.), a Pima-type cotton, and Acala 1517-75 (G. hirsutumL.), an Upland-type cotton, were compared to the prometryn-sensitive Upland-type cultivars, Delta Pine 5415 (G. hirsutum) and Acala 2711 glandless (G. hirsutum). Uptake and metabolism of prometryn by excised tissue in solution, uptake and translocation of prometryn by roots or hypocotyls in whole plants in soil, and the concentrations of prometryn in lysigenous glands in whole plants were compared among the cultivars. In the excised tissue study, root tissue absorbed more prometryn than did excised hypocotyl tissue over 2 hr for all cultivars; Pima S-7 root and hypocotyl tissue absorbed more prometryn than Acala 1517-75 or Delta Pine 5415 over time, and no metabolites of prometryn were found in any of the tissues. In the whole-plant study where roots or hypocotyls were exposed to prometryn in soil, prometryn root uptake by Delta Pine 5415 was lower than by Pima S-7 or Acala 1517-75, while hypocotyl uptake and translocation did not differ among cultivars. Therefore, differential prometryn tolerance among these cultivars cannot be explained by differences in uptake or translocation. However, uptake and translocation were greater in root-treated compared to hypocotyl-treated seedlings, regardless of cultivar, over time. Lysigenous glands contained higher levels of prometryn relative to other stem tissue; however, the amount of prometryn in glands was no greater in susceptible Delta Pine 5415 than in tolerant Pima S-7. Thus, differential prometryn tolerance in these cotton cultivars is not due to differential prometryn absorption, translocation, metabolism, or concentration in lysigenous glands.