title: Seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia (Compositae) in Nigeria, Africa.
abstract: We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage.
authors.affiliation: Department of Biological Sciences, University of Agriculture, P.M.B. 2240, Abeokuta, Ogun State, Nigeria. jareagbo@yahoo.com
authors.forename: D A
authors.initials: DA
authors.lastname: Agboola
authors.forename: W F
authors.initials: WF
authors.lastname: Idowu
authors.forename: M
authors.initials: M
authors.lastname: Kadiri
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000818:Animals; D001280:Atrazine / Q000494:pharmacology*; D004338:Drug Combinations; D018525:Germination / Q000187:drug effects / Q000502:physiology*; D006368:Helianthus / Q000502:physiology*; D006540:Herbicides / Q000494:pharmacology*; D007300:Insect Control; D020049:Isoptera / Q000502:physiology; D008027:Light; D008800:Mexico; D009549:Nigeria; D012621:Seasons; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development*; D012639:Seeds / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D000081:Acetamides; D004338:Drug Combinations; D006540:Herbicides; C000607803:primextra; D001280:Atrazine