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Book: Proceedings of the Second International Turfgrass Research Conference
Published by: American Society of Agronomy, Crop Science Society of America



  1.  p. 474-479
    Proceedings of the Second International Turfgrass Research Conference

    Eliot C. Roberts (ed.)

    ISBN: 978-0-89118-573-4


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Growth regulation of Kentucky bluegrasses with commercial and experimental growth regulators1

  1. T.L. Watschke


Posan [methyl 2-chloro-9-hydroxyfluorene-9-carboxylate; methyl 9-hydroxyfluo-rene-9-carboxylate;methyl 2,7-dichloro-9-hydroxyfluorene-9-carboxylate; diethanolamine salt of 6-hydroxy-3(2H)pyridazinone], Maintain CF-125 (same chemical formula as Posan, but different concentrations of constituents), and experimentais MBR 6033 (3′ -trifloro-methylsulfonamido-p-acetotoluidide), C-19490 (undisclosed), and granular endothal [7-oxabicyclo(2.2.1)heptane-2,3 dicarboxylic acid] were evaluated for foliar growth inhibition on ‘Merion’, ‘Pennstar’, ‘Delta’, and ‘K-109’ Kentucky bluegrasses (Poa pratensis, L.). Growth was depressed a minimum of 4 weeks by all materials applied May 19, 1972. Posan and Maintain applied at 0.7 kg ai/ha had less discoloration and longevity than experimentals. Growth of all grasses was stimulated in excess of the control after the inhibitory effects subsided. Reapplication at half rates of Posan and Maintain in July to reduce the stimulatory effect caused discoloration comparable to the rate applied in May with only slight growth reduction. Delta and K-109 were injured significantly more than Pennstar and Merion by both rates of the experimental compounds. Application of growth regulators to intensively managed fine turf appeared to have limited value due to decreased aesthetic quality and post-retardation stimulation for some chemicals. Additional index words: Plant growth, Turfgrass, Chlorflurenol, Maleic hydrazide, Endothal.

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Copyright © 1974. Copyright 1974 by the American Society of Agronomy, Inc. and the Crop Science Society of America, Inc., 5585 Guilford Rd., Madison, WI 53711 USA