Record Details
Field | Value |
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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 |