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Item Description Barba, Ramon Cabanos en_US 2009-09-09T19:45:39Z 2009-09-09T19:45:39Z 1967 en_US
dc.description Typescript. en_US
dc.description Thesis (Ph. D.)--University of Hawaii, 1967. en_US
dc.description Bibliography: leaves [105]-110. en_US
dc.description viii, 110 l illus., tables en_US
dc.description.abstract Field screening trials in Hawaii showed ametryne (2-methylmercapto-4- ethylamino-6-isopropylamino-s-triazine) to be a potentially important herbicide for bananas. Ametryne exhibited more effective weed control than atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine). Furthermore, atrazine caused injury to bananas in 2 of 3 locations used. Investigations were conducted to explain the differential selectivity of the 2 closely related s-triazine herbicides to bananas. Sand culture experiments-showed that both herbicides at concentrations of 0.4, 4, and 16 ppm in 2 liters of nutrient solution injured the plants. Plants grown in pots containing soils from the experimental fields showed increasing phytotoxicity to the herbicides in the fo1lowing order: Poamoho soil, Waimanalo soil, and Kauai soil. Ametryne was less injurious than atrazine but differences were not as pronounced as that under field conditions where ametryne did not exhibit phytotoxicity. Phytotoxicity was directly related to leachability of the herbicides and negatively related to adsorption capacity of each soil for the herbicides. Organic matter content seemed to partly explain the response observed. Selectivity appeared to be largely attributed to differential position of roots of banana plants in relation to herbicide placement rather than to inherent selectivity. Apparently, atrazine being less adsorbed by soil and more readily leached, moved to a greater depth upon receipt of a given amount of water resulting in crop injury. Laboratory studies confirmed results of greenhouse experiments that absorption, translocation and degradation of the herbicides by the plants did not account for the selectivity observed. Both of the herbicides were partly metabolized by the plants to their common hydroxy derivative and 2 other unidentified metabolites after 3 and 7 days of exposure to nutrient solutions containing C14-labelled ametryne and atrazine. When applied to the leaves with a surfactant the herbicides were absorbed and translocated in an acropetal direction to a very limited extent. Higher leaf content of free ammonia, free nitrate, and non-protein nitrogen, and lower chlorophyll content, were associated with plants receiving phytotoxic concentrations of ametryne and atrazine after 1 and 4 weeks from treatment. It appears that phytotoxic concentrations of these herbicides resulted in disturbance of the incorporation of nitrogen into more complex nitrogen containing plant constituents as proteins. In these experiments atrazine at 2 and 10 lb/A and ametryne at 10 lb/A applied to soil were phytotoxic to banana plants grown in pots. Ametryne at 2 lb/A did not injure the plants. en_US
dc.language.iso en-US en_US
dc.relation Theses for the degree of Doctor of Philosophy (University of Hawaii (Honolulu)). Horticulture; no. 138 en_US
dc.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. en_US
dc.subject Herbicides -- Testing en_US
dc.subject Bananas en_US
dc.title The selectivity and activity of s-triazine herbicides in banana plants en_US
dc.title S-traizine herbicides in banana plants en_US
dc.type Thesis en_US
dc.type.dcmi Text en_US

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