Accession Number:

ADA226125

Title:

Bioassay of Plant Growth Regulator Activity on Aquatic Plants

Descriptive Note:

Final rept.

Corporate Author:

PURDUE UNIV LAFAYETTE IN DEPT OF BOTANY AND PLANT PATHOLOGY

Report Date:

1990-07-01

Pagination or Media Count:

36.0

Abstract:

A laboratory bioassay system was developed to determine whether inhibitors of gibberellin synthesis could reduce plant height but maintain physiological competence in two weedy submersed aquatic plants, hydrilla Hydrilla verticillata Royle and Eurasian watermilfoil Myrioplyllum spicatum L.. The gibberellin synthesis inhibitors tested were uniconazol, flurprimidol, and paclobutrazol. Milfoil was more sensitive to be inhibitors than hydrilla. All three compounds were effective in reducing both main and lateral stem lengths in hydrilla, although the number of lateral stems was greatly increased over untreated controls. Hydrilla produced a stoloniferous growth habit, in contrast to milfoil in which the dominant growth form was a single reduced stem with numerous compressed buds. Photosynthesis, measured as oxygen evolution, was not significantly affected in either plant at dosages which stem reduction was obtained. Hydrilla had to be in constant contact with the compound in order to be affected, whereas milfoil required only 1 day to exposure to produce long- term effects. The bioassay suggests that these gibberellin synthesis inhibitors would have minimal adverse impacts on plant health but would be effective at reducing plant height in aquatic systems.

Subject Categories:

  • Agronomy, Horticulture and Aquiculture
  • Biology
  • Pesticides Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE