Use of 2,4-Dichlorophenoxyacetic Acid Herbicides on some Woody Tropical Plants
1948; University of Chicago Press; Volume: 109; Issue: 3 Linguagem: Inglês
10.1086/335484
ISSN1940-1205
Autores Tópico(s)Plant Physiology and Cultivation Studies
Resumo1. The herbicidal effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) has been tested on Aroma marabu (Dichrostachys nutans) and Guao (Comocladia dentata), two perennial and highly resistant woody weeds of Cuba. 2. As judged by criteria based on rapid defoliation and on ultimate apparent killing, a single spraying with 2,4-D in the sodium salt or ester form, at a concentration of 3 gm./l., or two sprayings 5 days apart at 2 gm./l., were almost completely herbicidal on Aroma. 3. Little, if any, regrowth of basal buds took place within 2 months of spraying, although controls which were cut back regenerated rapidly. There was some evidence of new growth from horizontal roots, however. 4. Addition of 0.5% Carbowax definitely increased the toxicity of aqueous 2,4-D sprays 5. With Guao, ordinary sprays were of only moderate effectiveness, but Weedone gave at least a 75% kill within 6 weeks 6. Some of the difficulties involved in assessing toxicity on woody plants are discussed. 7. The influence of stomatal opening and other conditions was briefly investigated.
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