The responses of 'Oregon 1604' snap beans (Phaseolus vulgaris L.), 'Early Thorogreen' lima beans (Phaseolus lunatus L.), and 'Takii's Extra Early' soybeans (Glycine max L.) to two methods of inoculation with rhizobium (seedcoating and furrow treatments) and rates of nitrogen fertilizer were studied in field experiments. Nitrogen rates ranged from 0 to 84 kg/ha. Nodulation was increased significantly by inoculation but decreased by nitrogen fertilization in three crops. Yield of snap beans was increased significantly from increasing nitrogen fertilizer but was not affected by inoculation. Neither nitrogen fertilizer nor inoculation influenced soybean yield. For soybeans and lima beans, furrow inoculation resulted in significantly higher nodulation than the seedcoating treatment. Nodulation of snap beans and soybeans was significantly decreased by nitrogen fertilizer in inoculated plots but not in check plots. Plant weight of lima beans was significantly increased by nitrogen fertilizer only when seedcoating inoculation was used. Plant stands of snap beans were increased 118% by captan seed treatment but nodulation was significantly reduced. / Graduation date: 1978

Recent reports have emphasized that foliar applications of stimulatory concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) induce greater growth and productivity of several crop plants. This stimulatory action of the hormone has been found to be augmented by simultaneous application of such micronutrients as iron, manganese, zinc, copper, and boron (Wort, 1964). However, no systematic attempt has so far been made to investigate physiological and biochemical changes induced in a relatively short period following these treatments. A correlation of such changes with final improvements in growth and yield may provide a better understanding of the mechanism of action of the hormone. In addition, the biochemical nature of the augmentory role played by micronutrients on 2,4-D action is yet undefined. It was therefore felt desirable to investigate these aspects. Bean plants (Phaseolus vulgaris L. Var. Top Crop) were grown in plastic cans under controlled environment in a growth room. When the plants were 2 weeks old, the following treatments were applied as foliar sprays: (1) 2,4-D (1 ppm), (2) micronutrient solution (Fe, Mn, Zn, Cu, B; 5x10⁻⁴ M) and (3) 2,4-D-mineral solution, with the same components as (2) plus 1 ppm 2,4-D. Measurements of juvenile growth, chemical composition of the plants, respiration and photosynthetic rates and activities of some of the key enzymes of carbohydrate and nitrogen metabolism were made 5, 10, and 15 days after the treatment, to determine the course and basis of stimulation. Yield of pods and seeds and the vitamin C content of pods were also determined. The results revealed that: (1) maximum stimulation resulted from the use of hormone-mineral spray, (2) treatments involving 2,4-D resulted in progressive increase in plant height, leaf number, and leaf area; fresh and dry weights of root, stem and leaves; chlorophyll content and total sugar in leaves, (3) sucrose and reducing sugars were lower in stems and roots of treated plants; (4) moisture content was not affected significantly by any treatment; (5) quantitative chromatographic determination of the free, ethanol-soluble amino acids revealed a reduction in amino acid content in 2,4-D-treated plants, particularly in leaves, and an increase in plants to which micro-nutrient spray had been applied. The amino acid content of plants treated with 2,4-D plus minerals was intermediate between those resulting from the other two treatments; (6) measurement made with intact plants using an infrared CO2 analyzer revealed increases in rates of respiration and photosynthesis of the aerial portions 10 and 15 days after treatment; (7) significant increases in the activity of phosphorylase, phosphoglyceryl kinase, succinic dehydrogenase, catalase, nitrate reductase, and transaminase in all organs were also apparent at 10 and 15 days after treatments involving 2,4-D; (8) treatments involving 2,4-D also resulted in significant increases (P=0.05) in number and fresh weight of green pods, in seed number, and in total seed weight. Weight of the individual seed was not significantly altered; (9) the green pods from treated plants had higher vitamin C content at harvest time, but the moisture content was not altered by treatment. The green pods of plants which had received 2,4-D alone or 2,4-D plus minerals lost less ascorbic acid and moisture during 4 days storage at room temperature. The stimulation of enzyme activities is explained on the basis of hypothesis proposed by Wort (1964) that 2,4-D may participate in the formation of substrate-enzyme-regulator complex. Minerals may affect the activity of formation of this complex. In proposing a physiological and biochemical basis for the stimulation in growth and yield under 2,4-D action, the following points are emphasized: (1) the stimulated rate of photosynthesis produced a larger amount of photosynthate which could be utilized in the biosynthesis of all cell constituents or serve as substrate for respiration; (2) the stimulated rate of respiration and activity of such enzymes as phosphoglyceryl kinase and succinic dehydrogenase resulted in an increased supply of available energy, as ATP and reduced nucleotides, for biosynthesis, and in larger amounts of keto acids which provide the carbon skeletons of amino acids; (3) the greater activity of nitrate reductase and transaminase resulted in an augmented supply of amino acids responsible for the enhanced synthesis of protein evident in greater growth and productivity. / Science, Faculty of / Botany, Department of / Graduate

The effects of two applications of foliar sprays made from kelp (Macrocystis intearifolia Bory) on growth of beans (Phaseolus vulgaris L.) under three moisture regimes were investigated. Date of kelp harvest had little effect on plants grown in water excess or deficit conditions, although means for kelp collected in spring tended to be higher. On soils maintained near field capacity, spray made from kelp collected in July resulted in increases in some bean yield components beyond the effects of kelp collected in spring or fall. The effect of storage of liquefied kelp at room temperature was also investigated and found to be soil moisture dependent. Leaf and root weights of plants grown in field capacity and dry soil respectively were lower for plants treated with kelp aged for 118 days compared to plants treated with kelp stored for longer or shorter durations. In wet soil conditions, the effect of sprays on plant height was reduced by storage of the liquefied kelp. Kelp extracts were fractionated by solvent partition. The butanolic fraction was shown to increase significantly many yield variables under wet soil conditions. This fraction had cytokinin-like activity in two bioassay systems, and contained substances co-eluting with isopentenyl adenine and zeatin in column, thin layer, and gas-liquid chromatography systems. Non-significant increases for some plant yield components resulting from application of unfractionated kelp paralleled these increases. A kelp fraction with undefined constituents increased some yield variables of plants grown in field capacity soil, as did a fraction with auxin and gibberellin-like activities in bioassay. The presence of inhibitors in the kelp was indicated by significantly lower pod yields under dry soil conditions, and a reduction in cytokinin-like bioassay activity when increasing amounts of kelp were assayed. The possibility that phytohormone deficits resulting from root stress are ameliorated by some components of the kelp spray is discussed. / Land and Food Systems, Faculty of / Graduate

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Recent investigations have shown that application of appropriate concentrations of naphthenate induces greater growth and yield of several crop plants. However, reports are lacking on the effect of naphthenate on plants grown under various temperature and light conditions and also on physiological and biochemical changes induced in bush bean (Phaseolus vulgaris L.Var. Top Crop) plants following naphthenate treatment. In the course of the present work the following aspects were investigated: 1) juvenile growth, as measured by fresh and dry weight of roots, stem and leaves, number and area of leaflets and plant height; 2) reproductive growth, as measured by flower number, number and fresh weight of pods, and number and weight of dry seeds; 3) chemical composition, such as moisture content of roots, stem, leaves, and pods, chlorophyll and carotenoid content of leaves, ascorbic acid content of green pods and loss of ascorbic acid by pods during storage for five days, and 4) such physiological and metabolic changes as rates of apparent photosynthesis and dark respiration, activities of the enzymes nitrate reductase, glutamic-pyruvic transaminase, phosphorylase and phosphoglyceryl kinase. Subsequent to KNap treatment, plants in some experiments were grown in growth rooms provided with 26°/26°, 26°/21° and 15°/15°C, day/night temperature. At 26°/26° and 15°/15° plants were grown under three different light intensities, 1500, 1000 and 500 ft-c. The results revealed that: (1) treatment with KNap resulted in increases in plant height, number and area of leaflets, fresh and dry weight of roots, stem and leaves, and total chlorophyll content in leaves; (2) measurements made with intact plants using an infrared CO₂ analyzer revealed increases in rates of apparent photosynthesis and dark respiration in treated plants; (3) the activity of the four enzymes mentioned was stimulated in plants treated with KNap; (4) increases in number and fresh weight of green pods, number and weight of seed were observed in treated plants; (5) treatment resulted in higher ascorbic acid content in green pods at harvest and the treatment had a protective action on ascorbic acid loss during storage. Different plant organs were found to respond differently to treatment depending on temperature and light intensity in which the plants were grown. The maximum relative stimulatory effect of KNap treatment was found mostly at 26°/21° and it was followed by 26°/26° and 15°/15°, in plants grown under a light intensity of 1500 ft-c. Plants grown at 26°/26° showed maximum relative stimulation in most instances in high light. The maximum relative stimulation for plants grown at 15°/15° was in medium light generally speaking. In proposing a physiological and biochemical basis for the stimulation of growth and yield following KNap treatment, the following points may be emphasized: (a) the stimulated rate of photosynthesis produced a larger amount of photosynthate which could be utilized in the biosynthesis of all cell constituents and serve as substrate for respiration and other chemical processes; (b) the stimulated rate of respiration and activity of phosphoglyceryl kinase resulted in an increased supply of available energy, as ATP and reduced nucleotides, for biosynthesis; (c) the augmented supply of amino acids resulting from the greater activity of nitrate reductase and transaminase would be favorable for enhanced synthesis of protein, evident in stimulated growth. / Science, Faculty of / Botany, Department of / Graduate