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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.
51

Ecophysiology of sugar beet cultivars and weed species subjected to water deficiency stress

Abdollahian-Noghabi, Mohammad January 1999 (has links)
No description available.
52

Aspects of the agro-ecology and control of Bromus sterilis L

Bulmer, R. H. C. January 1987 (has links)
No description available.
53

The role of cultivar choice for enhanced competitive ability of wheat

Bueno, Carmen de Lucas January 1996 (has links)
No description available.
54

Studies of weed-crop competition

Li, Bo January 1995 (has links)
No description available.
55

The population dynamics of field pansy (Viola arvensis) and red deadnettle (Lamium purpureum) in winter cereal and oilseed rape fields

Gilbert, J. January 1987 (has links)
No description available.
56

Fertility-Based Herbicide Injury Recovery from Clomazone in Hybrid Rice (Oryza sativa L.)

McKnight, Benjamin 1985- 14 March 2013 (has links)
Clomazone is a carotenoid biosynthesis inhibitor commonly used as a preemergence and postemergence herbicide in rice for the control of grass weeds. Rice injury can occur and symptoms are often associated with soil characteristics and environmental conditions. The objective of this research was to investigate how environmental conditions and planting density influence clomazone injury in rice plants. Also, different fertility treatments were assessed to determine if remediation from clomazone injury occurred. Field studies were conducted in 2008 and 2009 to determine the role of planting date, planting density and soil characteristics on clomazone injury in rice plants. Also, another field study was conducted in 2010 to assess any clomazone injury remediation benefits selected fertility treatments might have in rice cropping systems. In the 2008 and 2009 field studies, hybrid rice was seeded at three densities that comprised a range of slightly lower, slightly higher and commonly recommended planting rates. Two planting dates, March and April, were a test parameter to simulate early and optimal planting dates. Two locations with different soil characteristics, near Eagle Lake and Beaumont, TX, were the study sites. Clomazone herbicide treatments were applied at different rates and timings following planting. Visual injury ratings and yield data were collected during this two-year, two location study. Clomazone injury in rice was more severe in the coarse-textured soils planted at the early, March planting date near Eagle Lake. Visual injury ratings as high as 90% were observed in some plots. Injury was less severe in the April planting date near Eagle Lake, and at both planting timings near Beaumont. In both locations, clomazone injury did not translate into yield loss at any seeding rate or planting timing. In 2010, field studies were conducted near Eagle Lake and Ganado, TX to assess fertility-based clomazone injury remediation. In one experiment, hybrid rice plots were subject to linearly increasing rates of clomazone herbicide to produce a standard curve of clomazone injury. In the second experiment, a uniform, label rate of clomazone was applied to induce injury for the assessment of the effect of fertility amendments on clomazone-injured rice. Fertility treatments consisted of nitrogen-based fertilizers and foliar-applied iron sulfate and magnesium sulfate. Visual injury ratings, plant height, and yield were collected during the study. Also, tissue samples were collected three times for laboratory analysis of chlorophyll content. In the standard curve experiment, herbicide injury increased with increasingly higher rates of clomazone applied. The highest visual injury was observed in plots receiving the highest rates of clomazone. In the remediation experiment, fertility treatments had a significant effect in only one tissue-sampling event at Eagle Lake as determined by laboratory analysis for chlorophyll content. Fertility amendments did not have a significant effect on visual injury ratings at either location at any assessment event. Specific fertility treatments significantly increased plant height in three measurement events, and yield at the Ganado locations. Plots receiving treatments containing nitrogen fertilizers produced taller plants at both locations, and increased yield at the Ganado location.
57

Weed control in flue-cured tobacco.

Benoit, Diane Lyse. January 1979 (has links)
No description available.
58

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.
59

Chemical weed control : options in fibre flax

Mühleisen, Martin Bernd. January 2000 (has links)
No description available.
60

Weed control in flue-cured tobacco.

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

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