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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.
31

The role of cultivar choice for enhanced competitive ability of wheat

Bueno, Carmen de Lucas January 1996 (has links)
No description available.
32

Studies of weed-crop competition

Li, Bo January 1995 (has links)
No description available.
33

Weed control in flue-cured tobacco.

Benoit, Diane Lyse. January 1979 (has links)
No description available.
34

Chemical weed control : options in fibre flax

Mühleisen, Martin Bernd. January 2000 (has links)
There is an ongoing and increasing interest in the significant and essential role that food plays in the health and survival of all people. As masticatory efficiency diminishes drastically in edentulous patients, many researchers in the past two decades have been studying how dietary intake varies when different types of oral rehabilitation are provided. Since the use of implants to support prostheses in edentulous mandibles has been shown to significantly improve masticatory performance, the question remains as to whether this improvement will influence nutritional status. In the present study, we used several nutritional markers to compare the nutritional status of edentulous patients who randomly received either mandibular conventional dentures or implant-supported overdentures one year previously. Although the conventional denture wearers reported having more difficulty chewing hard foods, no significant differences were detected in any of the nutritional markers. Therefore, even though chewing is more difficult for the patients wearing conventional dentures, it appears that the nutritional status of these two groups is similar.
35

Chemical weed control : options in fibre flax

Mühleisen, Martin Bernd. January 2000 (has links)
No description available.
36

Weed control in flue-cured tobacco.

Benoit, Diane Lyse. January 1979 (has links)
No description available.
37

The biology of horseweed (Conyza canadensis (L.) Cron.) /

Bekech, Marilyn M. 01 January 1988 (has links) (PDF)
No description available.
38

Weed management in conventional, no-till, and transgenic corn with mesotrione combinations and other herbicides

Armel, Gregory Russell 30 April 2002 (has links)
Weed management programs in corn typically include herbicides applied both preemergence (PRE) and postemergence (POST) for season-long weed control. Mesotrione is a new triketone herbicide registered for PRE and POST control of broadleaf weeds in corn. Triketone herbicides function through inhibition of the enzyme p-hydroxyphenylpyruvate dioxygenase. Mesotrione applied PRE did not adequately control common lambsquarters (Chenopodium album L.), smooth pigweed (Amaranthus hybridus L.), common ragweed (Ambrosia artemisiifolia L.), or morningglory species (Ipomoea spp.) in conventional tillage corn, but control of these weeds was generally improved in no-till corn. Mesotrione combinations with acetochlor did not always improve control of broadleaf weeds, but increased control of smooth pigweed and giant foxtail (Setaria faberi Herrm.). POST applications of mesotrione at 105 g ai/ha controlled most annual broadleaf weeds except common ragweed, but did not control giant foxtail. The addition of atrazine at 280 g ai/ha to mesotrione, however, improved control of common ragweed. Tank-mixtures of glyphosate, imazethapyr, or imazethapyr plus imazapyr with mesotrione improved control of giant foxtail in herbicide-resistant corn. Corn injury was usually low from PRE and POST mesotrione applications in non-genetically modified corn, however, greater injury occurred in glyphosate-resistant varieties. Corn treated with mesotrione combinations generally yielded similar to corn treated with commercial standards. Mesotrione applied POST also suppressed the perennial weeds horsenettle (Solanum carolinense L.) and Canada thistle [Cirsium arvense (L.) Scop.]. Additions of atrazine increased the rate of plant tissue necrosis on these perennial weeds as compared to the slower bleaching symptoms associated with mesotrione applied alone. In general, Canada thistle plants were more susceptible to mesotrione in the rosette stage of growth than when bolting. Absorption, translocation, and metabolism of 14C mesotrione in Canada thistle was generally low. However, higher levels of absorption and translocation and lower root metabolism of mesotrione in rosette stage plants compared to bolting stage plants may explain why Canada thistle is more susceptible to mesotrione in the rosette stage of growth. The changes in symptomology and increased control from mesotrione plus atrazine tank-mixtures is likely due to the interrelationship between the modes of action of atrazine and mesotrione. / Ph. D.
39

The effect of mechanical weed cultivation on crop yield and quality,disease incidence and phenology in snap bean, carrot and lettuce crops /

Trembley, Marcella L. January 1997 (has links)
Inter-row mechanical cultivation was proposed as a supplement to or substitute for conventional weed control methods currently used in snap bean, carrot and lettuce production. Several types of cultivators were assessed and compared. The effect of mechanical cultivation on crop yield and quality was studied by counting, weighing and grading bean pods, carrot roots and lettuce heads. The effect of mechanical cultivation on disease incidence was studied by surveying fields during the season and by determining the number and weight of diseased pods, roots and heads at harvest. The relationship between the level of Cercospora blight on carrots and potential impacts on yield was also investigated by measuring plant characteristics and the amount of force needed to separate carrot foliage from root. The effect of mechanical cultivation on the phenology of snap bean flowering was studied by determining how long it took for a plant to produce 50% of its flowers and counting how many flowers and pods a plant produced. In general, mechanical cultivation did not affect normal crop production and may be used to replace or complement conventional weed control methods. There was little variation among different cultivators within one season, but cultivator effects differed among crops and from one year to the next.
40

The effect of mechanical weed cultivation on crop yield and quality,disease incidence and phenology in snap bean, carrot and lettuce crops /

Trembley, Marcella L. January 1997 (has links)
No description available.

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