A Simple Method for Expressing the Relative Efficacy of Plant Growth Regulators

摘要

A comparative study was conducted to determine the relative effectiveness of five retardants on growth of bean plants (Phaseolus vulgaris L. cv. Black Valentine) in solution culture. Utilizing dose response curves for each compound, we evolved a simple method for mathematically comparing the efficacy of each candidate compound against a standard. The retardants studied included: maleic hydrazide (MH, the standard against which other compounds were compared), propylphosphonic acid (NIA 10656), DPX-1108 (an E.I. du Pont de Nemours and Co. experimental compound whose structure has not yet been released), a-cyclopropyl-a-(4 methoxyphenyl)-5-pyrimidine methanol (ancymidol) and methyl-2-chloro-9-hydroxyfluorene-(9)-carboxylate (chlorflurenol). Advantages of this system include: ease of calculation, wide applicability, more meaningful terminology for plant scientists, an averaging technique for determining the overall effect from two or more growth parameters, and a means of mathematically comparing new materials tested against a standard. (Author)