Record Details

The influence of various climate and edaphic factors on the toxicity of 2-tert. butylamino-4-ethylamino-6-methylthio-s-triazine (Igran) to winter wheat (Triticum aestivum Vill., Host)

ScholarsArchive at Oregon State University

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Title The influence of various climate and edaphic factors on the toxicity of 2-tert. butylamino-4-ethylamino-6-methylthio-s-triazine (Igran) to winter wheat (Triticum aestivum Vill., Host)
Names Figuerola, Luis Fernan (creator)
Furtick, William R. (advisor)
Date Issued 1969-04-25 (iso8601)
Note Graduation date: 1969
Abstract Several studies were conducted to determine the influence of
various environmental factors on the toxicity of 2-tert.butylamino-
4-ethylamino-6-methylthio-s-triazirxe (Igran) to winter wheat.
The effect of temperature on Igran toxicity was studied by
growing wheat plants in pots submerged in water baths to control soil
temperature and in controlled-environment chambers. Igran was
more toxic to the test plants at 20-25 C than at 5-10 C. The lesser
toxicity at low temperature appeared to be correlated in part with
lower rates of absorption and translocation of the chemical.
Light intensity was shown to influence the activity of Igran.
High light intensity produced an effect similar to that of high
temperature and it was difficult to separate the individual action for
either climatic factor.
The effect of Igran on photosynthesis of wheat plants was
studied by measuring the CO₂
uptake with an infrared gas analyzer.
The activity of Igran was more pronounced at high light intensity.
Water availability in the soil influenced Igran action on winter
wheat. The higher the water content in the soil, under high temperature
and light intensity conditions, the higher the apparent absorption
and translocation of Igran. This effect was related to the adsorptive
capacity of soil particles. With increased water content in
the soil, Igran apparently becomes more available to the roots than
under low moisture conditions.
High nitrogen content in the growth medium favored Igran toxic
action on winter wheat. With lower nitrogen levels, although the
growth rate was diminished, chlorosis and necrosis were not as
noticeable as under high nitrogen content conditions.
Igran was less toxic when applied directly to the soil surface
than when incorporated into the soil. When the herbicide was placed
close to the root system, the toxicity was greatly increased.
Postemergence applications of Igran to the soil under high
illumination (2500-3000 ft-c) and high temperature (20-30 C) produced
severe injury to wheat even at low rates and at several stages
of growth. At low light intensity (500-800 ft-c) and low temperature
(5-10 C) few or no injury symptoms were observed. The determination of the factors affecting the toxicity of Igran
on winter wheat will aid in making improved recommendations for its
use to control a broad spectrum of undesired vegetation with a minimum
chance for damage to wheat plants.
Genre Thesis/Dissertation
Topic Herbicides -- Toxicology
Identifier http://hdl.handle.net/1957/46338

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