University of Illinois Urbana-Champaign

The life history and control of bigroot morning glory (Ipomoea pandurata)

Horak, Michael Joseph

This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.

Permalink

https://hdl.handle.net/2142/23227

Description

Title
The life history and control of bigroot morning glory (Ipomoea pandurata)
Author(s)
Horak, Michael Joseph
Issue Date
1990
Doctoral Committee Chair(s)
Wax, Loyd M.
Department of Study
Agronomy
Discipline
Agronomy
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
  • Agriculture, Agronomy
  • Biology, Plant Physiology
Language
eng
Abstract
  • Bigroot morningglory is a large rooted perennial weed which can be difficult to control due to a late emergence time, a large tap root which occurs below the plow layer, and the ability to reproduce from root cuttings or seed. Studies on bigroot morningglory germination, emergence, and growth and on herbicide efficacy, absorption and translocation in this weed, were conducted with the goal of developing effective control measures.
  • Studies showed increased seed germination with chemical or mechanical scarification. The optimum temperatures for germination were 20 or 25 C, while the best pH range for germination was between 6 and 8.5. Plant establishment was greatest at the 2 to 4 cm planting depth and decreased at greater depths. The emergence sequence of bigroot morningglory did not fit the models of hypogeal or epigeal germination. Plant establishment was rapid with 85% of 11 day old seedlings able to sprout after shoot removal.
  • Emergence of bigroot morningglory occurred 75 growing degree days (GDD) after seeding. Flowering and seed production began 630 GDD after emergence and continued until the first killing frost. Massive accumulation of dry matter occurred after 600 GDD for shoots and 900 GDD for the roots. First year plants became true perennials within six weeks of germination.
  • Excellent seedling control was obtained with triclopyr (99%), fluroxypyr (91%) and 2,4-D (95%). In field studies on established populations, the best season long suppression was obtained with 2,4-D or triclopyr at an early June application, or triclopyr at an early July application. Ratings taken the spring following treatment showed that glyphosate resulted in the best long term control.
  • Herbicide efficacy studies revealed that clopyralid, a compound with similar chemical and physiological characteristics to triclopyr, was ineffective on bigroot morningglory. Studies on these two compounds in bigroot morningglory were conducted to determine if absorption and translocation differences could account for differential control observed. Both compounds were readily absorbed (60% absorbed of total recovered at 144 h). Triclopyr was readily translocated, and at 24 h 15% of the herbicide absorbed had moved to the roots. Clopyralid translocation was also rapid and within 24 h, 20% had moved to the roots. It was concluded that absorption and translocation differences could not account for the differential efficacy.
Type of Resource
text
Permalink
http://hdl.handle.net/2142/23227
Copyright and License Information
Copyright 1990 Horak, Michael Joseph

Owning Collections

Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Agronomy