Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 477 for “"Agriculture, Agronomy"”.
-
The routes beneath the roots : a system map for prospective food innovators striving for sustainable disruption
… meet flaws? What sparks innovation in food and agriculture today and what would a food innovation map look like for the United States? The hereby report presents a selective, subjective and dynamic representation of food and agriculture innovation, after eight months of immersion in the American …
-
Fusarium stalk rot incidence in maize, Zea mays L., in relation to the European corn borer, Ostrinia nubilalis (Hubner) infestation, genotype maturity and eastern Ontario climatic gradient.
Development of maize, Zea mays L., germplasm resistant to the European corn borer, Ostrinia nubilalis (Hubner) and Fusarium fungal pests has been in progress for more than three decades as a worldwide cooperative effort. Some of the host plant resistance to the European corn borer and Fusarium has …
-
Host plant resistance and epidemiology of Fusarium ear rot in maize.
This thesis examines fusarium ear rot epidemiology in maize (Zea mays L.) and host plant resistance to Fusarium species causing ear rot, in eastern Canada, through three major groups of experiments. A three-year disease survey that determines the causal agents of maize ear rot in Ontario; a …
-
Field Measurements of Denitrification From Fertilizer Applied to Turfgrass
Denitrification and mass balance measurements of fertilizer N applied to turf was studied under field and greenhouse conditions. Highly enriched 15N-labeled KNO3 or urea was applied to replicated plots on a Flanagan silt loam soil under Kentucky bluegrass (Poa pratensis L.) or creeping bentrgrass …
-
The Effect of the Site of Nitrogen Assimilation on Plant Growth
In this dissertation, I have explored this question experimentally. My approach was to obtain plants with NO3- reduction mostly in the roots or mostly in the leaves, measure growth and biomass allocation parameters of those plants when grown on NO3-, and compare them to growth of wild-type (WT) …
-
Management and Interference Potential of Common Waterhemp (Amaranthus Rudis) in Soybean (Glycine Max)
Field experiments were conducted during 1996, 1997, and 1998 to determine the common waterhemp interference period soybean could tolerate without reducing seed yield. Removal of common waterhemp interference 2 weeks after soybean unifoliolate expansion resulted in soybean seed yield equivalent to a …
-
Fate and Utilization of Fertilizer in Inbred and Hybrid Corn Production
To evaluate the impact of N rate and crop rotation on uptake of fertilizer N in seed corn production, corn inbred lines were grown in corn-corn and corn-soybean (Glycine max L. Merr.) rotations using N application rates of 0 to 144 lb acre$\sp{-1}$. When corn was the previous crop, seed yield of …
-
Evaluation of Nitrogen Sources, Starter Fertilizers, and Amendments for No-Till Corn Production
No-till agricultural production creates a decidedly different soil environment than a conventional system that receives annual tillage, which presents challenges to the management of nitrogen (N) fertility. Two on-farm studies were conducted to evaluate N fertilizer sources, starter fertilizers, …
-
Analysis of the Effect of Two Tillage Systems on Soybean (Glycine Max (L.) Merrill) Growth
The majority of the existing literature suggests that on highly-drained, well structured soils of the Corn Belt, soybean yield is not substantially affected by tillage. Available reports of differences are in the minority. There is relatively little information as to what extent and under what …
-
Predicting Crop Yields and Productivity Indices for Illinois Soils
Comparing established (Circular 1156) crop yields with predicted 1970s crop yields, generated from soil property models from base and benchmark soils, predicted high R2 values of 0.90 for corn, 0.90 for soybean, 0.81 for wheat, 0.81 for oat, and 0.88 for hay. These crop yield models were tested …
-
Soybean's Future: Photosynthesis, Sucrose Transport, Dry Mass Accumulation and Yield in a Changing Atmosphere
Increasing atmospheric carbon dioxide concentration ([CO2]) is widely accepted, but the concomitant rise in tropospheric ozone concentration ([O3]) is less well publicized. Global [CO2] is expected to reach 550 ppm by the middle of this century and [O3] predicted to reach a global mean of 63 p.p.b. …
-
Indirect Effects of Elevated Carbon Dioxide on Members of Three Herbivorous Feeding Guilds on Soybean, Glycine Max
P. japonica prefers damaged leaves grown under elevated CO2 over damaged leaves grown under ambient CO2, which may be the result of increased complexity in volatile compounds in leaves grown under elevated CO2. Increased amounts of flavonols and decreased amounts of isoflavonoids in leaves grown …
-
Effect of Intercropping and Trap Cropping on the Diamondback Moth, Plutella Xylostella L., Its Natural Enemies and Other Brassicaceous Pests, And, Studies on Diadegma Insulare (Cresson), the Major Diamondback Moth Parasitoid
Laboratory studies on D. insulare revealed that it was better synchronized with its host when it developed in second instars, where survival to cocoon formation and adult emergence was also significantly higher than in third- or fourth-instar hosts. A greenhouse study at varying parasitoid and host …
-
Machine Vision Systems for Real-Time Plant Variability Sensing and in-Field Application
In-field variations associated with corn plant spacing, growth stage, and population can lead to a significant yield differences. Since the ability to reduce these variations is directly related to the planter performance, a machine vision-based emerged corn plant sensing system (ECS) was developed …
-
Ground Sensor Based Variable Rate Nitrogen Management
Integrating the multi-spectral imaging sensor with a variable-rate nitrogen application system, can provide the fundamental means for performing site-specific variable-rate nitrogen side-dressing applications. Using the estimated SPAD values to support sensor-based variable rate nitrogen …
-
Analysis of Soil Splash Erosion Under Simulated Rainfall
Threshold energy based on the regression results, required to initiate soil splash, was dependent upon soil type, with greater clay content soils exhibiting a greater threshold energy. Soil splash rate increased with increasing kinetic energy, with large differences between soils. Soil loss …
-
Direct and Indirect Effects of Elevated Carbon Dioxide and Ozone on the Canopy of a Soybean Agroecosystem
It is unknown how rising atmospheric CO2 and O3 will directly and indirectly alter canopy structure and scale to affect ecosystems. I determined how leaf area index (LAI) was directly affected by elevated [CO 2] and [O3]. By increasing photosynthetic efficiency, elevated [CO2] may increase maximum …
-
Genetic Analysis of Nitrogen Use Efficiency and Related Traits in the IBMRIL X IHP1 Population of Maize
Nitrogen (N) is often the limiting factor in the production of maize grain and most maize hybrids exhibit a strong response to supplemental N in the form of increased grain yield. Despite the economical and environmental importance of the N-response of maize, little is known about the specific …
-
Understanding the Interaction of Mesotrione and Atrazine in Redroot Pigweed (Amaranthus Retroflexus)
This dissertation covers an in-depth analysis on the interaction of mesotrione and atrazine and their impact on herbicide resistance stewardship and weed control efficacy. Mesotrione and atrazine are herbicides primarily used in corn, or maize. Herbicide resistance and a reduced number of new …
-
Interactions Between Herbicides and Soybean Diseases
Greenhouse studies were conducted to evaluate several soybean lines and cultivars for resistance to R. solani and to determine the inheritance of resistance. Ninety ancestral lines and 700 current cultivars were evaluated. Most of the lines and cultivars evaluated were susceptible, however, 21 of …
Page 1 of 24