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Theses and Dissertations - UTB/UTPA

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Management Of Silverleaf Whitefly, Bemisia Argentifolii Bellows And Perring (Hemiptera: Aleyrodidae), Using Non-Crop Companion Plants In Organically-Managed Cantaloupe Systems In South Texas, Ruth Renee Colyer Aug 2014

Management Of Silverleaf Whitefly, Bemisia Argentifolii Bellows And Perring (Hemiptera: Aleyrodidae), Using Non-Crop Companion Plants In Organically-Managed Cantaloupe Systems In South Texas, Ruth Renee Colyer

Theses and Dissertations - UTB/UTPA

Field trials in three separate phases of research were carried out from March, 2010, to August, 2012, to determine the effects of inter-cropping cantaloupe (Cucumis melo var. inodorus) with select non-crop companion plants in an effort to develop organic production strategies for melons in South Texas without the use of pesticides. A research program was designed and initiated to assess the effects of the companion plants and their ability to: 1) attract insect pollinators, and 2) repel or suppress pest species without affecting beneficial natural enemy complexes. The hypotheses were: 1) that organically-managed cantaloupe systems grown with non-crop companion plants …


Monitoring Citrus Nutrition In The Rio Grande Valley For Fertilizer Recommendations, Iram Lopez May 2014

Monitoring Citrus Nutrition In The Rio Grande Valley For Fertilizer Recommendations, Iram Lopez

Theses and Dissertations - UTB/UTPA

Soil fertility and plant nutrition is crucial for a better yield and consistent harvest in the Rio Grande Valley for local farmers growing citrus trees. A field of oranges and a field of grapefruits were monitored and nutrition deficiencies were noticed that played an important role during fruit set. Soil samples that were taken throughout the year were analyzed via a carbon dioxide extraction method that mimics the way plants naturally take up nutrients or extract nutrients from every soil type. Macronutrients such as the N, P, K, Na, Ca, Mg and some of the micronutrients (Zn, Fe, Mn, and …


Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia Jul 2011

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …


Evaluation Of Streptomycetes For Biological Control Of Gummy Stem Blight Disease Of Cantaloupe, Shima Chaudhary May 2009

Evaluation Of Streptomycetes For Biological Control Of Gummy Stem Blight Disease Of Cantaloupe, Shima Chaudhary

Theses and Dissertations - UTB/UTPA

Studies were conducted to evaluate the efficacy of Streptomyces isolates for the biological control of gummy stem blight (GSB) in cantaloupes (Cucumis melo var. ‘Primo’) in south Texas. Plants were monitored for seedling emergence, lesions, mortality and plant growth under laboratory, greenhouse and field conditions. Comparison of treatment groups indicated a significant reduction in plant mortality and enhanced growth of infected plants exposed to three Streptomyces isolates (MA1F4#2, WI1B#5, and MA2A4 #2), which appear to be most effective when used in combination. In all three experiments, GSB infection was associated with a significant reduction in reflectance of near-infrared wavelengths (700-1,100 …