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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Resposta fisiológica de alface a subdoses de maturadores utilizados em cana-de-açucar /

de Souza Rodrigues, Juliana January 2019 (has links)
Orientador: Pedro Luis da Costa Aguiar Alves / Resumo: É prática comum durante o cultivo da cana-de-açúcar o uso de maturadores de forma antecipar a colheita. No entanto, considerando que pode haver cultivos próximos, como o de hortaliças, é importante ressaltar os cuidados necessários quando dá aplicação destes produtos, que é realizada por via aérea, a fim de evitar a deriva. Culturas sensíveis, como a da alface, podem sofrer efeitos deletérios. Sendo assim, objetivou-se com este trabalho avaliar o efeito da deriva dos maturadores glyphosate, trinexapac-ethyl e sulfometuron comumente utilizados em cana-de-açúcar no crescimento da alface ‘Lucy Brown’ e ‘Vanda’. O experimento foi instalado em ambiente aberto do Laboratório de Plantas Daninhas (LAPDA), UNESP/FCAV nos meses de outubro e novembro. Mudas de alface foram transplantadas para vaso com capacidade para 5 L, sendo cada planta a parcela experimental. O experimento foi constituído de 15 tratamentos estabelecidos no delineamento em blocos casualizados em esquema fatorial 3x5, com cinco repetições. O primeiro fator correspondeu aos maturadores e o segundo às subdoses, de forma a simular a deriva, sendo essas de 0, 3%, 6%, 9% e 12% da dose recomendada de cada produto, sendo aplicados quando as mudas apresentavam ao início da formação da cabeça, para a cultivar Lucy Brown e o estádio de 6 a 7 folhas para a cultivar Vanda. Após aplicação, as avaliações ocorreram aos 5, 10, 15 e 20 dias após aplicação (DAA). Foram realizadas avaliações visuais, com base na escala EWRC (1964), teor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: It is common practice during the cultivation of sugarcane to use ripeners in order to anticipate the harvest. However, considering that there may be crops nearby, such as vegetables, it is important to emphasize the necessary care when applying these products, which is carried out by air, in order to avoid drifting. Sensitive crops, such as lettuce, can suffer deleterious effects. Therefore, the aim of this work was to evaluate the effect of the glyphosate, trinexapac-ethyl and sulfometuron ripening effects commonly used in sugarcane on 'Lucy Brown' and 'Vanda' lettuce growth. The experiment was installed in an open environment at the Laboratory of Weeds (LAPDA), UNESP / FCAV in the months of October and November. Lettuce seedlings were transplanted to a 5 L pot, each plant being the experimental plot. The experiment consisted of 15 treatments established in a randomized complete block design in a 3x5 factorial scheme, with five replications. The first factor corresponded to the ripeners and the second to the subdoses, in order to simulate the drift, being 0, 3%, 6%, 9% and 12% of the recommended dose of each product, being applied when the seedlings presented at the beginning of the head formation, for the Lucy Brown cultivar and the 6 to 7 leaf stage for the Vanda cultivar. After application, the evaluations occurred at 5, 10, 15 and 20 days after application (DAA). Visual evaluations were performed based on the EWRC scale (1964), chlorophyll content, quantum efficiency of ... (Complete abstract click electronic access below) / Mestre
292

Fate and metabolism of BAS 290-H in a model ecosystem

Chang, Kuo-Mei 01 August 1973 (has links)
The use of chemicals to control economic pests has grown in this century both in the amount and the diversity of materials used (Headley and Lewis, 1967). About ten billion pounds of pesticides have been used in the United States since 1945. It is estimated that there are 340 million acres of cultivated lands in the Continental United States. Of this amount, approximately 119 million acres were sprayed with herbicides, 97 million acres were treated with insecticides and 25 million acres were treated with fungicides and other minor pesticides (Matsumura, 1972).
293

The Economics of Controlling Tall Larkspur with Selective Herbicides

Willis, Reed W. 01 May 1965 (has links)
The state of Utah is located in a semi-arid climatic zone and contains about 52.7 million acres of land which varies topographically from smooth desert plains and valleys to steep mountain ranges (8).
294

Time Interval Required to Measure Effects of Herbicides on Canada-Thistle and Field Bindweed

Whipple, Charles Ralph 01 May 1961 (has links)
Canada-thistle and field bindweed are two troublesome weeds in Utah. Jensen, in cooperation with county weed committees, conducted a weed survey in the state. Seriousness of weeds was listed by counties. Field bindweed was considered to be either a serious or very serious weed in every county except one, and Canada-thistle was classified in these two categories in over one-half of the counties.
295

Effects of Preemergence Herbicides on Hybrid Bermudagrass Root Growth, Establishment, and Sod Harvestability

Begitschke, Erick G 08 December 2017 (has links)
Preemergence herbicides are generally considered as a group to negatively affect hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) establishment. However, little is known about the effects upon hybrid bermudagrass root growth, establishment, and sod harvestability. Several research projects were conducted at Mississippi State University to determine the effects of commonly used preemergence herbicides on hybrid bermudagrass sod production. Measured response variables included visually estimated hybrid bermudagrass cover, normalized difference vegetative index (NDVI), ratio vegetative index (RVI), relative chlorophyll concentration (CI-RE), sod tensile strength, root mass, root length, root surface area, average root diameter, and root carbohydrate concentration after application of these herbicides. While several of these preemergence herbicides initially reduced hybrid bermudagrass growth, hybrid bermudagrass was generally able to recover and outgrow the herbicidal effects by the end of the growing season.
296

Selective chemical control of quack grass Agropyron repens (L.) Beauv. in seed production fields of birdsfoot trefoil Lotus corniculatus (L.) cv. Leo

MacQuarrie, J. A. January 1987 (has links)
No description available.
297

Control of hexazinone tolerant weeds in lowbush blueberries

Howatt, Stephen M. (Stephen Michael) January 1992 (has links)
No description available.
298

Inhibition of tuberization and flowering in yellow nutsedge (Cyperus esculentus L.).

Chaudhry, Aman Ulla. January 1975 (has links)
No description available.
299

Environmental degradative products of the herbicide alachlor : quantitative assessment of mutagenic potential.

Tessier, Daniel M. 01 January 1994 (has links) (PDF)
No description available.
300

Evaluating effects of contemporary preemergence herbicides on plugged St. Augustinegrass grow-in using multispectral and traditional evaluation methods.

Wilber, Amy L. 30 April 2021 (has links)
St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] is a widely used lawn grass in the southeastern United States. St. Augustinegrass is typically vegetatively established from plugs or sod. Establishment of St. Augustinegrass sod can be slowed due to weed competition. Weed-infested sod may not be harvestable and is less desirable by end users. Preemergence herbicides are used to prevent weed infestation; however, preemergence herbicides often negatively affect sod grow-in. Current research evaluated the effects of contemporary preemergence herbicides on St. Augustinegrass grow-in from plugs. Grow-in was evaluated using visual estimates of percentage St. Augustinegrass cover, as well as Normalized Difference Vegetation Index (NDVI), Ratio Vegetation Index (RVI), and Chlorophyll Index-Red Edge (CI-RE) collected by handheld and aerial multispectral sensors. A sharable workflow was created in ArcGIS Pro to extract vegetation indices from aerial imagery. Trends of increased time to grow-in due to herbicide treatment were detected by visual and multispectral assessments.

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