Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript. / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1953 W46 / Master of Science

Call number: LD2668 .T4 1963 C96 / Master of Science

Master of Science / Department of Agronomy / Nathan O. Nelson / Glyphosate-resistant (GR) soybean cultivars are widely accepted in the United States. Glyphosate-resistance provides many benefits to production agriculture, yet GR soybeans may require some additional management practices. The objectives of this research are to (a) determine response of GR and conventional (CV) soybean near isoline to manganese fertilization, (b) determine nutrient concentration and uptake in GR and CV soybean, (c) determine differences in yield of GR and CV soybean varieties, (d) quantifying Mn uptake when glyphosate is and is not applied to glyphosate-resistant soybean, and (e) determine glyphosate effect on soybean response to Mn treatments. A field study was conducted at 5 locations in Kansas from 2006 through 2007. Manganese soil test levels ranged from 4 to 52 mg Mn/kg. Soybean (near isoline) varieties were planted at each location in a split-block design with 4 replications. Manganese treatments consisted of soil-applied MnSO[subscript]4 at 0, 2.8, 5.6, and 8.4 kg Mn/ha and foliar applied Mn at 0.22 and 0.45 kg Mn/ha. Leaf tissue and whole plant samples were taken at approximately R1, R3, and R6 growth stages and analyzed for N, P, K, Mn, and other nutrient concentrations. Few significant differences were found between varieties for concentration of any nutrient. Overall nutrient uptake under optimal growth conditions was greater in GR soybean than CV soybean varieties. There were no yield differences between GR and CV soybean varieties at low yielding locations (< 3.3 Mg/ha). In high yielding environments, CV soybean yield was greater than GR soybean yield for the 0 kg Mn/ha rate. However, granular Mn additions increased yield of GR soybean but did not affect CV soybean yield while foliar Mn treatments at high yielding locations increased yields in GR and CV soybean. In addition, a greenhouse study was conducted with a completely randomized block design having 5 blocks. Manganese treatments in the greenhouse study consisted of soil-applied MnSO[subscript]4 at 0, 8.5, 17, and 25.5 mg Mn/pot and foliar applications of 0.66 and 1.33 mg Mn/pot. Treatments were with and without glyphosate applications. Glyphosate applications did not alter Mn concentrations or total Mn uptake in the soybean biomass.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: A 240-day growth study was conducted to determine the suitability of soybean meal (SBM) as an alternative protein source to fish meal (FM) in the diet of commercially produced South African abalone (Haliotis midae). The suitability of SBM was determined by a close evaluation of the following key factors: feed water stability, morphological impact on the abalone intestine and the effect on the growth performance of abalone. The study was comprised of two phases: a fish meal replacement phase (Phase A) and an enzyme treatment phase (Phase B). Diets used in Phase A consisted of a control fish meal diet (Control=22%FM, 0%SBM), a fish meal-soybean meal diet (FMSBM=20%FM, 15%SBM), a soybean meal-low diet (SBMlow=0%FM, 15%SBM) and a soybean meal diet (SBM=0%FM, SBM30%). In Phase B, the FM diet and SBM diet were used as basal diets (FME0 and SBME0). These diets were then treated with three commercial enzyme products, namely, a β- glucanase (FME1 and SBME1), xylanase (FME2 and SBME2) and α-D-galactosidase (FME3 and SBME3). Subsequently, all three enzymes were combined to make two treatments (FME123 and SBME123). With regard to the gut morphology and growth trials, a thirteenth energy enhanced commercial animal protein-free diet (ECO) was used. In Phase A (fish meal replacement), the findings revealed that water stability did not differ significantly between treatments. In Phase B (enzyme treatment) however, the water stability of β- glucanase treated feeds was significantly lower than that of the control FM diet. It was also observed that in comparison to the control FM diet, soybean meal based diets have a significantly greater effect on intestinal morphology. With reference to Phase A (fish meal replacement), by the end of the 240 day growth trial period, it was evident that animals fed on the commercial (ECO) diet were significantly heavier than those given the control FM diet. With regard to final length in mm, feed conversion ratio (FCR) and specific growth rate (SGR) for mass and length, no differences between the treatments were noted. It was also found that the condition of the ECO fed animals was significantly better in comparison to the other treatment fed animals. No significant differences were observed between the FM and three FMreplaced diets however. With reference to Phase B (enzyme treatment), it was noted that once again, after the 240 day period, abalone fed on the ECO diet were significantly heavier in terms of their final weight when compared to those fed on the other diets. As in Phase A, no differences in FCR and SGR for mass and length were observed. Measurements of the animals’ final length (as observed on day 240) revealed that those fed on the ECO diet were significantly longer than those given the FME1, SBME1 and SBME3 diets. At the end of the trial, abalone fed on the ECO diet were also in significantly better condition than those fed on the SBM, FME3 and FME123 diets. In terms of production performance, no significant difference was found between the SBM diets and FM diets and enzyme supplementation did not significantly increase the production performance either. The results of this study therefore show that SBM has great potential to be used as a FM-replacement diet. The improved performance of the ECO diet was expected due to its energy content. / AFRIKAANSE OPSOMMING: ‘n Groeistudie is gedoen met die perlemoen (Haliotis midae) oor ʼn tydperk van 240 dae om die geskiktheid van sojaboonoliekoek (SBM) as ‘n alternatiewe proteïenbron ter vervanging van vismeel (FM) in die rantsoen te evalueer. Geskiktheid van SBM is getoets aan die hand van waterstabiliteit van voer, morfologie van die spysverteringskanaal en die invloed daarvan op groei van die perlemoen. Die studie het uit twee fases bestaan naamlik ‘n vismeel (FM) vervangingsfase (Fase A) gevolg deur ‘n ensiem behandelingsfase (Fase B). Die diëte wat gebruik was sluit in ’n Kontrole dieet wat slegs vismeel as proteïenbron bevat (Kontrole = 22%FM, 0%SBM), ‘n 2de dieet wat beide vismeel en sojaboonoliekoekmeel bevat (FMSBM =20%FM, 15% SBM), ‘n 3de dieet wat ‘n lae vlak sojaboonoliekoekmeel bevat (SBMlow =0%FM, 15%SBM) en 4de dieet met ʼn hoër sojaboonoliekoek vlak (SBM = 0%FM, 30% SBM). Die basale diëte van Fase B was dieselfde as die FM en SBM diëte van Fase A (FME0 en SBM0) met die verskil dat dit met kommersiële ensieme behandel is. Die onderskeie behandelings was gedoen met β-glukanase (FME1 en SBME1), xylanase (FME2 en SBME2) en α-D-galactosidase (FME3 en SBME3) asook ‘n kombinasie van die drie ensieme (FME123 en SBME123). ‘n Addisionele behandeling bestaande uit ‘n kommersiële diereproteïenvrye dieet (ECO) is as bygevoeg as kontrole vir die histologie gedeelte van die proef. Tydens Fase A is gevind dat waterstabiliteit van die onderskeie diëte nie betekenisvol verskil het nie. Tydens Fase B het ensiembehandeling met β-glukanase egter aanleiding gegee tot betekenisvolle laer waterstabiliteit van FME1 en SBME1 diëte in vergelyking met die FM dieet. Histologiese ontledings het getoon dat die SBM diëte ‘n groter negatiewe effek op die morfologie van die spysverteringkanaal gehad het as die kontrole FM dieet. Fase A het getoon dat die ECO dieet beter groeiresultate opgelewer het as die FM dieet, in terme van liggaamsmassa en kondisiefaktor van die perlemoen. Finale skulplengte (mm), voeromsetverhouding (VOV) en spesifieke groeitempo (SGT) vir massa en lengte was egter nie betekenisvol verskillend vir enige van die behandelings nie. Geen betekenisvolle verskille is ook gevind tussen die FM en enige van die FM vervangingsdiëte nie. Resultate vir Fase B het getoon dat diere wat die ECO dieet gevoer is betekenisvol swaarder was as diere wat ander voere gevoer is. Geen betekenisvolle verskille is waargeneem vir VOV en SGT van massa en lengte nie. Finale lengte van die diere wat ECO gevoer is was langer as die van die FME1, SBME1 en SBME3 diëte. Die ECO diere het ook in betekenisvol beter kondisiefaktor vertoon as diere wat SBM, FME3 en FME123 diëte gevoer is. Geen betekenisvolle verskille in produksie parameters is opgemerk tussen die FM en SBM diëte nie en die toevoeging van ensieme het ook nie ‘n betekenisvolle invloed gehad nie. Die gevolgtrekking is dat sojaboonoliekoekmeel suksesvol aangewend kan word vir die vervanging van vismeel in perlemoen diëte.

Soybean (Glycine max L. Merr.) planting date and plant density are agronomic decisions made simultaneously at the beginning of the growing season that can be used to maximize yield and economic return. Research on these basic soybean agronomic decisions must be conducted to support the expansion of soybean production in northern growing regions of the Northern Great Plains (NGP). The objectives of this study were to evaluate the effects of planting dates based on soil temperature on soybean emergence, maturity, and yield for short and long season varieties in Manitoba, and to determine optimum soybean plant density for early to very late planting dates in northern growing regions of the NGP. In the first experiment, calendar date had a greater influence than soil temperature at planting on soybean yield. Soybean yield declined with later planting rather than increasing soil temperature at planting. The earliest planting dates resulted in the greatest soybean yields. In the second experiment, soybean yield-density relationships were responsive to planting date. Yield-density relationships formed early/mid (May 4 to 26) and late/very late (June 2 to 23) planting date groups for combined site years. Early/mid planting dates resulted in greater maximum yields. According to the yield-density model, true yield maximization did not occur for any planting dates and site years within the range of plant densities tested in this field study. Soybean economic optimum seed densities (EOSDs) were much lower than predicted plant densities that maximized yield. Soybean EOSDs were identified as 492,000 and 314,000 seeds ha-1 by marginal cost analysis for early/mid and late/very late planting, respectfully. These values were sensitive to changes in soybean grain price and seed cost. Thus, growers need to adjust EOSDs for changes in price and cost. A combined analysis of soybean yields from both experiments using similar target plant densities determined that a significant negative linear relationship existed between soybean yield and planting date. The greatest soybean yields resulted from early planting and declined by 16 kg ha-1 for each one-day delay in planting from Apr 27 to June 16. However, yield responses varied among site years. The overall recommendation from this study would be to plant soybeans during the month of May at a profit-maximizing seed density, accounting for fluctuating grain price and seed cost. / May 2017

Lack of technical knowledge and proper soybean cultivars are barriers for organic farmers to take advantage of increased organic soybean demand in Manitoba from domestic and international markets. The objective of the present study was to evaluate the performance of 12 early season non-GM food grade soybean cultivars under organic management in southern Manitoba. Cultivars were seeded on four organic farms and one transition to organic farm in southern Manitoba in 2014 and 2015. The mean cultivar yield ranged from 1384 to 1807 kg ha-1, with a mean of 1536 kg ha-1. Cultivars ‘Savanna’ and ‘Toma’ were high performers, but exhibited low stability across sites. Partial Least Squares Regression Analysis indicated that soybean mature height, and biomass at R5 positively contributed to final grain yield. Early height positively contributed to biomass at R5 but negatively affected final grain yield. Soil nitrate content negatively contributed to final grain yield. Weed competitiveness was of particular interest in this study. Contrary to previous reports, cultivars that exhibited early season vigour often resulted in lower yields, biomass accumulation, and increased weed presence as compared to other cultivars. / October 2016

Master of Science / Department of Agronomy / Dorivar Ruiz Diaz / The application of micronutrients to increase yields has become more popular with increased commodity prices and higher yielding crops. Two studies were completed evaluating secondary and micronutrient for soybean (Glycine max [L.] Merr.) and wheat (Triticum aestivum).The objective of the first study was to evaluate the response of soybean, under a double crop system after wheat, to soil-and foliar-applied macro and micronutrients. Macronutrients (N, P, K) were applied at 22 kg ha[superscript]-[superscript]1, micronutrients (Fe, Mn, Zn) were soil applied at 11 kg ha[superscript]-[superscript]1and S was applied at 22 kg ha[superscript]-[superscript]1. Plant response parameters were evaluated including changes in nutrient concentration, and seed yield response. Tissue samples were collected at the respective R1 growth stage. Samples were analyzed for the nutrients applied with the fertilizer treatments. Soybean seed yield slightly responded to soil-applied S, Mn, and Zn. When micronutrients were foliar-applied, seed yield was significantly decreased. The second study evaluated the application of S and micronutrients to winter wheat. The objectives were to evaluate the wheat response to sulfur and micronutrient fertilization and evaluate soil testing and tissue analysis as diagnostic tools. Fertilizer treatments consisted of sulfur, iron, manganese, zinc, boron, copper. All of the micronutrients were sulfate-based products and the sulfur treatments were applied as gypsum. Fertilizer treatments were applied as topdress in early spring. Soil samples were collected before fertilizer application and after harvest. Flag leaf samples were collected and analyzed for the nutrients applied with the fertilizer treatments. Significant increases in tissue concentration were observed when Zn, B, and S were applied. Significant increases in soil test Zn, Cu, B, and S were observed compared to the control treatment. Despite the increases in soil test concentration across locations, no significant increases in yield by any of the nutrients or combination of nutrients were observed.