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Effects Of Plant Stress On Facultative Apomixis In Boechera (Brassicaceae), Mayelyn Mateo De Arias

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In flowering plants, apomixis is asexual reproduction by seeds. Apomixis allows the production of offspring with the same genetic characteristics as the mother plant. Fertilization is not required. Apomixis could become a tool for naturally cloning high-yielding crop hybrids through their own seed. However, apomixis does not occur in major crop plants, except for citrus. In the present study, genes that might cause apomixis in naturally occurring apomictic plants were investigated. Sexual and apomictic species of the genus Boechera were exposed to stressed and non-stressed conditions. Effects of these treatments on the expression of apomixis was then measured. Stress triggered …

Ammonium And Nitrate Effects On Growth, Development And Nutrient Uptake Of Hydroponic Wheat, Thomas M. Hooten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long-term effects of low and high NH₄⁺/ NO₃^- uptake ratios in a system with rigorous control of pH and nitrogen concentration are poorly understood. In two replicate studies, two cultivars of wheat (Triticum aestivum) were grown to maturity with three NH₄⁺/ NO₃^- ratios in hydroponic solution: 0/100, 25/75, and 85/15%. Nitrogen was controlled at ample levels throughout the 70-d life cycle and pH was controlled at 5.8 ± 0.2. An equimolar ratio of NH₄⁺ to Cl^- was used to facilitate charge balance. Nitrogen consumption …

Investigations Of Field Performance And Physiological Effects Of Metsulfuron And Metsulfuron Combinations On Field Bindweed (Convolvulus Arvensis L.), Hamid Rahimian Mashhadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field bindweed (Convolvulus arvensis L.) is a noxious perennial weed of many fallow and cropland fields all over the world. Present control methods are not satisfactory for field bindweed. Metsulfuron, 2[[[[(4-methoxy-6-methyl-1,3,5-triazine-2-yl) amino] carbonyl] amino] sulfonyl] benzoic acid, is a new herbicide that has been shown to have activity on bindweed especially when tank mixed with other herbicides. This study was conducted to investigate the field performance and some physiological effects of metsulfuron on field bindweed.

Neither metsulfuron alone nor metsulfuron combinations gave persistent control of field bindweed. Metsulfuron usually increased the activity of other bindweed herbicides. Herbicide application to …

Anatomical Effects Of Dicamba On Pea Root Tissues, Brent George Ovard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Peas (Pisum sativum L. Var Alaska) were allowed to absorb calcium and magnesium chloride for 8 hours and then were germinated in a potassium phosphate buffer pH 6.5 for 40 hours. Peas were then treated with 0, 0.1, 0.3, or 0.5 ppm dicamba (3,6-dichloro-o-anisic acid) and harvested at 24, 48, and 72 hour intervals. The following determinations were recorded: root elongation, nuclear volume, and anatomical modifications.

Root elongation recordings showed that dicamba prevented normal root elongation. Treatments induced very short thick primary roots.

Measurements of nuclear volume indicated that all herbicide concentrations were able to reduce the …

The Effects Of Dcpa And Trifluralin On Northern Root-Knot Nematode (Meloidogyne Hapla Chitwood) Infection Of Selected Vegetables, Rulon Kent Romney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The interaction of herbicides and Northern root-knot nematodes (Meloidogyne hapla Chitwood) on onions and beans was studied in the greenhouse. Seeds of onions (Allium cepa L.) were planted in soil treated with different levels of dimethyl 2,3,5,6-tetrachloroterephthalate (DCPA). Seeds of beans (Phaseolus vulgaris L.) were planted in soil treated with different levels of DCPA or α, α, α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). Seedlings were inoculated with root-knot nematode larvae after 2 week's growth.

DCPA reduced root and shoot growth on onions but did not significantly affect bean growth. Trifluralin significantly reduced root and shoot …

Some Effects Of The Under Snow Environment On Growth And Carbohydrate Content Of Claytonia Lanceolata Pursh, Bryce D. Bennett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies were conducted in a mountain habitat to determine the effects of altered light and temperature upon the natural growth and/or carbohydrate cycles of Claytonia lanceolata during the period of winter snow cover. Treatments included natural control, light exclusion, and temperature alteration by insulation and by heating for a brief period. Monthly measurements were made of soil temperature (upper 12 cm), shoot development, soluble sugar, and soluble starch. The quantity and quality of light penetrating the snow cover was also determined.

About 0.0052% of the available visible light (400-750 nm) penetrated 70 cm of snow and 0.02% penetrated 50 cm …

The Morphological, Anatomical, And Histochemical Effects Of Eptc On Oat Seedlings, Jacinta Yu-Rui Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Morphological, anatomical, and histochemical effects of S-ethyl dipropylthiocarbamate (EPTC) on Avena sativa var. overland were studied after treatment of seeds at various EPTC concentrations.

The oat seed germination percentage was not affected by EPTC treatment. EPTC delayed initial root and coleoptile development at all concentrations used. Two or three days after treatment, however, the roots of seedlings treated with EPTC concentrations lower than 3 ppm grew at the same rate as the untreated seedlings and showed no abnormalities. Primary and adventitious root growth of seedlings treated with 3 ppm and higher was inhibited. Most of the adventitious roots remained in …

The Anatomical And Morphological Effects Of Dcpa On Seedlings Of Selected Species Of Plants, Bijan Shaybany

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Seeds of oat, green foxtail, squash and tomato were germinated in soil treated with different levels of DCPA (dimethyl 2, 3, 5, 6-tetrachlorote-rephthalate). The concentrations used varied according to the sensitivity of the plants to the chemical.

The response of oat and foxtail to DCPA was similar. The growth of booth root and shoot was reduced. This reduction was directly related to the concentration of DCPA. Anatomical studies showed that cells in the shoot and root meristems of treated plants were completely disarranged and that some of the cells of these regions were hypertrophied. Some clumping of nuclei was observed …

The Morphological And Anatomical Effects Of Pyrazon On Beans And Pigweed, James E. Rodebush

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Morphological and anatomical effects of pyrazon, 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone, on Phaseolus vulgaris L. and Amaranthus retroflexus L. were studied after treatment of seeds or seedlings at various pyrazon concentration, exposure times and environmental regimes.

Beans treated with pyrazon developed various chlorotic and necrotic symptoms on the unifoliate leaves. Chlorosis and necrosis were observed first on the leaf margins. Beans treated with pyrazon under a complete dark regime developed symptoms much later than those under an alternating light and dark regime. Pyrazon treated pigweed displayed symptoms similar to those on beans.

Pyrazon induced abnormal chloroplasts and graded cellular collapse in the unifoliate leaves …

The Effects Of Fertilizer And Moisture On The Yield Of Sweet Corn, Rex F. Nielson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sweet corn is rapidly becoming an important cash crop in many of the irrigated regions of the intermountain West. The lacome from this crop is relatively small in comparison to that from other major agricultural products; however, sweet corn production has a definite place in the economy of the region.

One of the factors limiting increasing acreage of sweet corn in many areas is low yields. Yields have been increased naterially in recent years with the development of hybrid varieties, superior to the standard varieties previously used. Better cultural practices are improving yields, but much remains to be done in …