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You searched for +publisher:"Texas A&M University" +contributor:("Rowland, Diane"). Showing records 1 – 3 of 3 total matches.

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Texas A&M University

1. Sconiers, Warren Boyce. Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions.

Degree: 2014, Texas A&M University

Drought is expected to become more prevalent in our future and influence plant-insect interactions in natural and agricultural systems. There is an established interest in predicting the effects of drought on plant-insect interactions, with over 500 published studies. Despite this intensive effort, researchers cannot accurately predict the effects of water deficit stress on insect performance. To address this, I tested hypotheses aimed to predict insect performance and abundance and developed a hypothesis that may better predict herbivore performance on stressed plants. I tested the Pulsed Stress Hypothesis which predicts that insect herbivores feeding on drought stressed plants will increase in abundance on plants that are pulsed stressed rather than continuously stressed. I conducted two, 10-week field studies to test the effects of drought on arthropods using 0.6 hectares of cotton. Stress was implemented by withholding water from continuously stressed plants and using pulsed watering for pulsed stressed plants. Piercing-sucking herbivores (i.e., thrips, stinkbugs, fleahoppers) were more abundant on pulsed stressed plants than continuously stressed plants. In contrast, chewing herbivores (e.g., grasshoppers, caterpillars) were similar in abundance on stressed plants. This suggests that the variation we see in herbivore response to stressed plants is dependent upon the severity and frequency of drought in addition to herbivore feeding guild. For my third field study, I tested the interactions of the timing of cotton aphid infestation, cotton development, and only pulsed stress. I had herbivore exclusion cages with only aphids inside and either on seedling or fruiting cotton. I largely found that cotton may compensate for early season damage from aphids and pulsed stress, but the combination of the two greatly impact cotton development. I conducted a meta-analysis on herbivore performance, macronutrients, and allelochemicals to determine the relationship between stress-induced changes in plants and herbivore performance. I used Metawin 2.0 to analyze the data from 42 published studies and found that macronutrients were the most important factor in determining herbivore performance on stressed plants. With this evidence, I devised the Nutrient Availability Hypothesis which predicted that the concentration of stress-induced changes in macronutrients in stressed plants will determine herbivore performance. Advisors/Committee Members: Eubanks, Micky (advisor), Behmer, Spencer (committee member), Salzman, Keyan (committee member), Rowland, Diane (committee member).

Subjects/Keywords: Insect herbivores; drought stress

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Sconiers, W. B. (2014). Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153516

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Sconiers, Warren Boyce. “Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions.” 2014. Thesis, Texas A&M University. Accessed September 18, 2019. http://hdl.handle.net/1969.1/153516.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Sconiers, Warren Boyce. “Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions.” 2014. Web. 18 Sep 2019.

Vancouver:

Sconiers WB. Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Sep 18]. Available from: http://hdl.handle.net/1969.1/153516.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Sconiers WB. Stressed Plants and Herbivores: Exploring the Mechanisms of Drought's Impact on Cotton Physiology and Plant-Herbivore Interactions. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153516

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Texas A&M University

2. Darapuneni, Murali. Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas.

Degree: 2012, Texas A&M University

Finding the alternate biofuel feedstock(s) in addition to and/or replacement of traditional soybean feedstock is necessary to meet the future demand of biofuels. Two field studies were conducted in diverse environments in Texas during 2007-2011 to evaluate the yield, adaptation, and oil content of 4 cool-season crop species (rapeseed, safflower, flax, and camelina). In addition to the evaluation of yield and adaptation in these cool-season crops, two more studies were conducted during 2009-2011 to study flax yield components (field study) and the effect of vernalization and photoperiod on flowering of flax (growth chamber study). Out of two field studies conducted in Texas, the evaluation of four cool-season crops was designed as a randomized complete block with fifty-one genotypes (four species) and three replications in nine locations across the Texas. In addition to the evaluation of cool-season crops, an exclusive replicated study was conducted in flax to evaluate 20 genotypes for the yield, adaptation, and association between yield and its components in three locations in South Texas. Additionally, a growth chamber study was setup as a split-split plot design with twenty genotypes, two vernalized treatments (vernalized and unvernalized), and two photoperiods (10 hours and 14 hours). Spring rapeseed (canola) and safflower were the highest yielding crops with a maximum yield of 1372 kg ha-1 and 1240 kg ha-1, respectively. In South and Central Texas, fall - seeded flax yield averaged 1075 kg ha^-1 with a mean oil content of 38.3%. The flax genotype evaluation in Southeast Texas suggested that all genotypes developed in Texas showed relative cold tolerance compared to genotypes developed in other locations. A cross between Caldwell / Dillman (Texas genotype) was highly adapted to the environments of southeast Texas. Nekoma and York (genotypes developed in North Dakota) yielded well in non-cold years (> -2 degrees C) in College Station. Overall, flax is well adapted to growth in the area surrounding College Station, TX. The results of association of yield and its components in flax suggest that tiller number was the most significant contributing factor (p<0.05) affecting yield of flax in all three locations. However, the effect of tiller number was almost negated by the effect of pods per tiller (compensatory) in two out of three locations. The effect of vernalization and photoperiod on flowering of 20 genotypes of flax suggested that Texas genotypes delayed anthesis for 7 days or more in non-vernalized seedlings. These genotypes also delayed anthesis for 12 days or more in vernalized and short day conditions compared to vernalized and long day conditions. In summary, the spring rapeseed in diverse environments of Texas and fall-planted flax in South Texas showed promising yield and adaptation. Selection for more productive tiller number and intrinsic earliness of flowering to reduce the time of maturation would benefit the flax yields in Southeast Texas. Safflower was widely adapted to Texas and with increased… Advisors/Committee Members: Ibrahim, Amir (advisor), Morgan, Gaylon D. (advisor), Duncan, Robert W. (committee member), Rowland, Diane L. (committee member), Hays, Dirk B. (committee member).

Subjects/Keywords: Falx; Rapeseed; Safflower; Camelina; Oilseed crops; Biodiesel; Yield components; Vernalization; Photoperiodism

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Darapuneni, M. (2012). Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11522

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Darapuneni, Murali. “Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas.” 2012. Thesis, Texas A&M University. Accessed September 18, 2019. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11522.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Darapuneni, Murali. “Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas.” 2012. Web. 18 Sep 2019.

Vancouver:

Darapuneni M. Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Sep 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11522.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Darapuneni M. Evaluation of Flax and Other Cool-Season Oilseed Crops for Yield and Adaptation in Texas. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11522

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Wen, Yujin. Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas.

Degree: 2012, Texas A&M University

The urban water demand in Southwest Texas has grown rapidly in recent years due to the population increases in urban areas, which caused conflict between municipal and agricultural water use. Deficit irrigation is one important measure for solving this problem. A field experiment with seven different irrigation treatments and four cotton varieties was conducted at the Texas AgriLife Research and Extension Center at Uvalde in the summers of 2008 and 2009 to examine the water saving potential and related phenological/physiological responses in Southwest Texas. The results showed that: 1) The threshold deficit ratio for a traditional deficit irrigation scheme falls between 0.7 and 0.8 for cotton production in Southwest Texas under a low energy precision application (LEPA) sprinkler irrigation system. The 70 percent evapotranspiration (ET)-initialled regulated deficit irrigation scheme (70R) performed well in maintaining lint yield in most cotton varieties tested. The significant changes detected in lint quality failed to introduce premiums or discounts in cotton price. 2) The phenological parameters (plant height, node number and flower/fruit number) showed clear trends that illustrate the relationship between increased stress level and decreased plant growth and development. The observed inconsistency of the physiological responses in the two growing seasons may imply that physiological parameters are not good direct predictors of lint yield if measurements are conducted only on a point basis. The partitioning coefficients of boll dry weight in both years failed to show a significant difference between deficit irrigation treatments and the control, indicating that reallocation of carbohydrates may not be the major factor of maintaining lint yield for the deficit irrigation treatments. 3) Economic analysis showed that due to the low water price, it is not currently profitable to adopt deficit irrigation. In case that water price is increased, it may become more profitable to adopt deficit irrigation. This work provides reference information to water authorities and policy makers to set quotas for municipal and agricultural water use and to value water properly through setting different water prices. Advisors/Committee Members: Cothren, J. Tom (advisor), Rowland, Diane L. (advisor), Piccinni, Giovanni (committee member), Leskovar, Daniel I. (committee member), Woodard, Joshua D. (committee member).

Subjects/Keywords: cotton production; deficit irrigation; drought stress; production function; carbon assimilation rate; water use efficiency

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wen, Y. (2012). Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9937

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Wen, Yujin. “Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas.” 2012. Thesis, Texas A&M University. Accessed September 18, 2019. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9937.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Wen, Yujin. “Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas.” 2012. Web. 18 Sep 2019.

Vancouver:

Wen Y. Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Sep 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9937.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wen Y. Cotton Production under Traditional and Regulated Deficit Irrigation Schemes in Southwest Texas. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9937

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.