Record Details
The influence of various surfactant-herbicide ratios in three volumes of water on the toxicity of dalapon, paraquat, and terbacil to winter oats (Avena sativa L.)
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The influence of various surfactant-herbicide ratios in three volumes of water on the toxicity of dalapon, paraquat, and terbacil to winter oats (Avena sativa L.) |
| Names |
Migchelbrink, Kenneth John
(creator) Appleby, Arnold P. (advisor) |
| Date Issued | 1969-06-23 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Several studies were conducted to determine if a more consistent predictor of phytotoxicity to winter oats could be obtained with a surfactant-herbicide ratio or a per-unit-volume concentration of surfactant, independent of volume. The herbicides tested were 2,2-dichloropropionic acid (dalapon), 1,1'-dimethyl-4, 4'-bipyridinium (paraquat), and 3-tert-butyl-5-chloro-6-methyluracil (terbacil) with the nonionic surfactant X-77 (80% alkylaryl polyoxyethylene glycols, free fatty acids, and isopropanol) in 25, 50, and 75 gallons of water. All plants were grown in the greenhouse with no supplemental light. Ten plants per pot constituted a replication. All pots were placed in watering trays and irrigated as needed. Neither a constant surfactant-herbicide ratio nor a per-unit-volume concentration of surfactant proved to be a consistent predictor of phytotoxicity. There was a trend of increased phytotoxicity with increasing volumes of water with paraquat and terbacil at the 1/4 lb/acre rate. With the 9 lb/acre rate of dalapon, maximum phytotoxic effects were obtained at the highest volume and the highest rate of surfactant. At the 6 lb/acre rate of dalapon, increased phytotoxic effects were exhibited with a decrease in volume and an increase in surfactant. High rates of surfactant with terbacil produced necrotic effects one day after spraying. The symptoms were similar to a contact herbicide such as paraquat. High rates of surfactant without herbicide caused phytotoxic effects. The high rates of surfactant used alone caused an orange appearance in the apical portion of the leaves. One experiment with terbacil indicated that phytotoxicity may be closely related to drying time of the spray solution on the oat leaf. Using drying time as a criterion for predicting phytotoxicity may encompass the many factors related to successful and consistent surfactant activity. Additional testing of this theory should be pursued. |
| Genre | Thesis/Dissertation |
| Topic | Herbicides -- Toxicology |
| Identifier | http://hdl.handle.net/1957/46252 |
