Dissertationen zum Thema „Seed treatment“

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in three Arizona locations; Maricopa, Marana, and Safford. Stand counts were taken after emergence at all three locations and percent emergence (PEM) was calculated. Significant differences in percent emergence due to seed treatments were observed in the both sample dates at Marana. Maricopa and Safford showed no statistically significant differences due treatment.

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in three Arizona locations; Maricopa, Marana, and Safford. Stand counts were taken on two separate dates after emergence at all three locations and percent emergence (PEM) was calculated. Significant differences in percent emergence due to treatment were observed in the both sample dates at Marana and Safford. Maricopa showed very little significant differences due treatment.

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in two Arizona locations; Maricopa and Marana. Stand counts were taken on two separate dates after emergence at both Maricopa and Marana and percent emergence was calculated. Significant differences in percent emergence due to treatment were observed in both sample dates at Marana. Results at Maricopa were not statistically significant but similar trends to those at Marana were observed with treatment number 6 (no treatment) having the lowest percent emergence and treatment number 2 (combination of Nu-Flow ND and Apron TL) having the highest emergence.

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in two Arizona locations; Maricopa and Marana. Stand counts were taken on two separate dates after emergence at both Maricopa and Marana and percent emergence was calculated. Significant differences in percent emergence due to treatment were observed in the first sample date at Marana with the treatment combination of NuFlow ND and Maxim having the highest percent emergence. Results from the second sample date at Marana were statistically significant but similar treatment ranking was observed. Results at Maricopa showed no statistically significant differences due to treatment for either sample date.

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in three Arizona locations; Maricopa, Marana, and Safford. Stand counts were taken on two separate dates after emergence and percent emergence was calculated. Among the three locations only one, Marana, showed significant differences among treatments. The highest percent emergence being seeds treated with Nu-Flow ND at a rate of 7.5 fl oz/cwt. The untreated control placed last in the ranking at this location.

Six different seed treatments and one in furrow granular treatment were used in a field with a history of black root rot, caused by Thielaviopsis basicola. The treatment was a follow-up on the study done the previous year (1). Stand counts, root lengths and seed cotton yields were taken to see if any of the treatments increased stand counts or stimulated root growth. Thielaviopsis was not isolated in the plants this year, so the effect of the fungicides on this pathogen were not evaluated. Stand counts were, however, significantly influenced by the seed treatments.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
NU-Zone (imazalil) + Nu-Flow ND (TCMTB + Chloroneb), NU-Flow ND, and Vitavax (carboxin) were evaluated as seed treatments with and without in-furrow PCNB. The following was learned: - Vitavax-treated seed got out of the ground faster than the other treatments, which brings out the possibility that NU-Flow or NU-Zone slows germination. - Stands and root development were slightly better when NUZone was present. - NU-Zone + NU-Flow ND seed treatment is not totally effective in controlling black root rot in heavily inoculated soils. - NU-Flow ND alone is the least effective of the treatments. - In-furrow PCNB did not affect yields.

Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012
A series of incubation studies and greenhouse experiments were conducted to evaluate the use of EM seed treatments, at different application levels, handling techniques and soil conditions on germination and seedling vigour of selected cultivars of maize, sorghum and sunflower. Two incubation studies were conducted to evaluate the germination and seedling vigour of maize, sorghum and sunflower seeds treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and diluted at three different levels (0.01%, 0.1% and 1.0%) compared to a control treated with pure water. Results revealed no significant differences under optimum germination conditions, while seedlings under cold stress indicated that M-EM treatments positively affected germination and seedling vigour compared to the control treatments. Two incubation studies were also conducted to evaluate the germination and seedling vigour of maize, sorghum and sunflower seeds treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and exposed to the influences of irradiation and temperature fluctuation. From the results became clear that the correct storage and handling is essential in optimizing the effect of M-EM on seeds. Even though M-EM was exposed to irradiation and temperature fluctuation, M-EM still had positive effects on germination and seedling vigour. Pot experiments were conducted to determine the effect of EM as seed treatment, at different dilutions, on germination, seedling vigour and dry mass of maize, sorghum and sunflower at different planted depths. Germination were not affected by the M-EM treatment, while shoot length results indicated that seed treated with M-EM could have significant effect on seedling survival. A greater effect was visible on the shoot length of shallow planted seeds, than on deeper planted seeds. From the results no single company, ratio or dilution could be prescribed as paramount. To further investigate the effect of M-EM subjected to the influences of irradiation and temperature fluctuation; maize, sorghum and sunflower seeds were treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and exposed to the influences of irradiation and temperature fluctuation and planted in soil. M-EM treatments only benefited the germination of deeper planted sorghum seeds compared to the control treatments. The shoot lengths of deeper planted maize and sunflower seed were positively increased by the M-EM treatments while also resulting in significant results for the overall shoot length of sorghum. The third pot study was conducted to determine the influence of EM as a seed treatment on maize, sorghum and sunflower planted in three different soils, namely: sterilized soil, soil treated with M-EM and Fusarium containing soil. Germination and seedling vigour results of the sterilized and M-EM treated soil revealed to be superior to that of the Fusarium containing soil. From the results was concluded that M-EM treatments will probably improve early seedling growth of maize, sorghum and sunflower compared to untreated seed and that M-EM seed treatment and a pre-plant EM soil treatment might assist seeds in unfavourable germination and growth conditions.

Cottonseed was treated with several fungicide treatments in an effort to protect the seed and seedling from disease. Seed germination and vigor was evaluated in three Arizona locations; Maricopa, Marana, and Safford. Stand counts were taken on two separate dates after emergence at both Safford and Marana and once at Maricopa and percent emergence was calculated. Among the three locations two, Marana and Safford, showed significant differences among treatments. Treatment number 5 placed first at both locations where significant differences were found. The untreated control placed last in the ranking at both Marana and Safford for all dates of sampling.

Thesis (MScAgric.)--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: Experi!11entsin KwaZulu-Natal showed that seed treatment with molybdenum (Mo) could double the yield and increase the protein content by 1.9% of soybeans grown on acidic soils. However, it was also found that soybean yield at five of the localities was reduced on average by 8% after Mo seed treatment. It was surmised that the yield reductions observed after Mo seed treatment were connected to the quality of the seed used for planting. The aim of this project was to assess the relationship between seed quality and Mo seed treatment and find a fast, easy quality assessment test that could be used to adapt Mo treatments according to seed quality. The first investigation entailed assessing the quality of the seed obtained, from various seed lots, for planting. A number of different seed quality testing techniques were performed and they included the accelerated ageing test, tetrazolium test, conductivity test, standard germination test and an emergence . test planted at different depths with incubation at different temperatures. All the test results were compared with the accelerated ageing test results, to find the test most closely correlated to the accelerated ageing test, which is regarded as the most accurate indicator of soybean seed vigour. It was found that the emergence test where the seeds where planted at 10 cm presented a close correlation with the accelerated ageing test. An assessment of seed quality revealed that the four different seed lots provided seed of three significantly different levels of quality, which could be used for further investigations. The second investigation was concerned with the reaction of the seed of different quality levels to Mo seed treatment. Firstly, seeds from four different seed lots were treated with five different concentrations of Mo and planted under acidic conditions. The establishment was monitored up until six weeks, at which point the experiment was terminated. In the second planting, seeds from the four different seed lots were treated with six different concentrations of Mo and planted under optimum pH conditions. Emergence was monitored and after thinning out the remaining plants were left to mature and produce seed. The emergence percentage results from both of these two plantings did not reveal the alleged positive effect Mo seed treatment has produced in the field and no definite relationship between seed quality and Mo seed treatment was observed. The third investigation was concerned with the effect that osmoconditioning had on the reaction of seed to Mo seed treatment. Seeds from two seed lots, one of very poor quality and the other of good quality, were pre-treated with four different levels of poly-ethylene glycol (PEG 6000) and then treated with four concentrations of Mo. They were planted under optimum pH conditions and establishment was monitored. After being thinned out the remaining plants were allowed to mature and produce seed. The emergence percentage results revealed that the PEG pre-treatments greatly improved emergence percentages, especially in the poor quality seed. There were some positive effects of Mo seed treatment observed where the lower concentrations of Mo were used, but again, no definite relationship between seed quality and Mo seed treatment was found. PEG pre-treatment appeared to help make the seeds more "resistant" to the harmful effects of Mo.
AFRIKAANSE OPSOMMING: Navorsing in KwaZulu-Natal het aangetoon dat saadbehandeling met molibdeen (Mo) die opbrengs van sojabone op suurgrond kan verdubbel en die proteieninhoud met tot 1.9% kan verhoog. Daar is egter ook gevind dat sojaboonopbrengs op vyf lokaliteite met gemiddeld 8% gedaal het na saadbehandeling met Mo. "nVermoede bestaan dat die opbrengsverlagings wat voorgekom het na saadbehandeling met Mo verband hou met die kwaliteit van saad wat vir die aanplantings gebruik is. Die doel van die projek was om vas te stel wat die verband tussen saadkwaliteit en Mo saadbehandeling is en om "n vinnige en maklike toets te vind om saadkwaliteit te bepaal om sodoende Mo behandelings aan te pas volgens saadkwaliteit. In die eerste eksperiment is die kwaliteit van verskillende saadlotte wat verkry is, getoets. "n Aantal verskillende tegnieke om saadkwaliteit te bepaal is uitgevoer. Die tegnieke was die versnelde verouderingstoets, tetrazoliumtoets, konduktiwiteitstoets, standaard ontkiemingstoets en "n vestigingstoets waar saad op verskillende dieptes geplant en by verskillende temperature geïnkubeer is. Die resultate van die verskillende toetse is gekorreleer met die resultate van die versnelde verouderingstoets, wat beskou word as die toets wat die beste aanduiding gee van saadgroeikragtigheid. Daar is gevind dat sade wat 10 cm diep in sand geplant is, se opkoms die beste korrelasie met die versnelde verouderingstoets toon en dus as "n goeie aanduiding van die kwaliteit van saad beskou kan word. Daar is gevind dat daar drie saadlotte is met duidelike kwaliteitsverskille wat gebruik kon word in verdere eksperimente. Die tweede eksperiment het die reaksie van saad van verskillende kwaliteitsvlakke teenoor molibdeen saadbehandeling ondersoek. Eerstens is saad van vier verskillende saadlotte behandel met vyf verskillende konsentrasies Mo en onder baie suur toestande geplant. Die vestiging is gemonitor vir ses weke waarna die eksperiment gestaak is. Daarna is saad van dieselfde vier saadlotte behandel met ses verskillende Mo konsentrasies en onder optimum pH toestande geplant. Vestiging is gemonitor en na ses weke is die plante uitgedun en twee plante per pot is gelaat om saad te produseer. Die ~ vestigingspersentasie van beide die eerste en tweede plantings het nie die verwagte positiewe effek teenoor Mo saadbehandeling getoon nie en geen betekenisvolle verwantskap tussen saadkwaliteit en Mo saadbehandeling kon waargeneem word nie. Die derde eksperiment het die invloed van osmokondisionering op die reaksie van saad op Mo saadbehandeling ondersoek. Saad van twee saadlotte, een van goeie kwaliteit en een van swak kwaliteit, is voorafbehandel met poli-etileen glikol (PEG 6000) en daarna met vier konsentrasies van Mo behandel. Die sade is onder optimum pH toestande geplant en die vestiging is gemonitor. Nadat dit uitgedun is, is die oorblywende twee plante gelaat om saad te produseer. Die vestigingspersentasies het getoon dat PEG voorafbehandelings vestiging betekenisvol verbeter, veral in die geval van lae kwaliteit saad. Daar was 'n . positiewe effek van Mo saadbehandeling waar relatief lae konsentrasies molibdeen toegedien is, maar daar kon weereens nie 'n duidelike verwantskap tussen saadkwaliteit en Mo saadbehandeling waargeneem word nie. Dit blyk dat PEG voorafbehandeling die sade meer bestand teen die skadelike invloed van Mo gemaak het.

Field experiments were conducted at four locations in Arizona (Yuma, Maricopa, Marana, Safford) to evaluate 16 cottonseed treatments on cotton that included 12 on Upland (Q. hirsutum L.) and 4 on Pima (Gossvpium barbadense L.). Stand counts were taken to evaluate the effectiveness of each treatment. Statistical analysis showed no significant differences among the treatments used for the Upland cottonseed. Significant differences were found among the treatments used for the Pima cotton seed at the Marana and Safford locations only.

Field experiments were conducted at three locations in Arizona (Maricopa, Marana, Safford) to evaluate 12 cottonseed treatments on Upland cotton (G. hirsutum L.). Stand counts were taken to evaluate the effectiveness of each treatment. Statistical analysis showed no significant differences among the treatments used at the Marana location. Significant differences were found among the treatments used at the Maricopa and Safford locations.

Field experiments were conducted at three locations in Arizona (Maricopa, Marana, Safford) to evaluate 9 cottonseed treatments on Upland cotton (G. hirsutum L.). Stand counts were taken to evaluate the effectiveness of each treatment. Statistical analysis showed no significant differences among the treatments used at the Maricopa location. Significant differences were found among the treatments used at the Marana and Safford locations.

Three upland cotton varieties (Deltapine 5415, Stoneville 474, and SureGrow 125) were subjected to three seed treatments (non or control, standard commercial triple treated, and standard commercial plus Prevail added to the hopper box at 1 lb product /100 lb cottonseed) to determine seed germination and vigor in a Mohave Valley field prone to Rhizoctonia infection of cotton seedlings.

Thesis (MScAgric)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: The influence of chemical seed treatments on the germination, seedling survival and yield of canola (cv. Varola 44) was investigated in a series of incubation studies, glasshouse experiments, as well as field trials in the canola producing areas in the Western Cape Province. Incubation experiments were conducted to compare germination and seedling growth of untreated (control) seed with that of seed treated at different application rates (0.5, 1.0 and 2.0 times the recommended) of Cruiser® and SA-combination (which consists of Thiulin® at 0.5g a.i.; Apron® at 0.0815 g a.i.; Gaucho® at 0.6125 g a.i. and Rovral® at 0.9975 g a.i.). The results indicated that seed treatment (all rates of SA-combination and highest rate of Cruiser) delayed germination and seedling growth, especially if the seed was subjected to the Accelerated Ageing Test. Glasshouse studies with pasteurised soil at different water contents, seed sources (storage periods) and planting depths confirmed the phytotoxic effects of the chemical seed treatments in the absence of soil borne pathogens. From the results it became clear that extreme water conditions (very wet or dry) increased the suppressing effect on germination and seedling growth, but that no phytotoxic reactions occurred in moist (favourable soil water conditions) soil, regardless of application rate of the chemicals used, planting depth and seed source. In a second glasshouse experiment conducted in moist soil (kept at 50% of field water capacity to prevent any toxic effects) from seven different localities that were naturally infested with pathogens, both chemicals proved to be effective where soil borne pathogens (Rhizocfonia so/ani and Pythium spp.) occurred. No clear trend could however be found due to either chemical or application rates used. Finally, field trials were conducted to study the effect of chemical seed treatments on the plant populations and yield of canola planted in different row widths (17 and 34 cm) and seeding rates (3, 5 and 7 kq.ha'). Results showed that treated seeds produced more plants.rn" and yielded more than untreated seeds at Roodebloem Experimental Farm, while the highest seeding rate produced significantly more plants.rn" (Roodebloem and Langgewens Experimental Farms), but not significantly higher yields than the lowest seeding rate at the same locality. Although row width did not have an effect on plant population, yield (Roodebloem 2003) was significantly less at the wider (34 cm) rows. As in earlier experiments, no consistent differences between the two chemicals used were found. These results clearly illustrated both the negative (in the absence of pathogens) and positive (where soil borne pathogens do occur) effects that chemical seed treatments may have on the germination, seedling growth and even yield of canola under local environmental and soil conditions. Because no significant differences were found between the chemicals used, both chemicals should be regarded as efficient. More research, especially under field conditions and with more cultivars, is needed before the registration of a chemical for seed treatment could be considered.
AFRIKAANSE OPSOMMING: Die invloed van chemiese saadbehandeling op die ontkieming, saailing oorlewing en opbrengs van canola (cv. Varola 44) is ondersoek in 'n reeks inkubasie studies, glashuis eksperimente en veldproewe in die canolaproduserende gebiede in die Wes Kaap Provinsie. Inkubasie eksperimente is uitgevoer om die ontkieming en saailing groei van onbehandelde (kontrole) saad te vergelyk met dié van saad wat behandel is teen verskillende dosisse (0.5, 1.0 en 2.0 keer die aanbevole) van Cruiser® en SA-kombinasie (wat bestaan uit Thiulin® teen 0.5g a.i.; Apron® teen 0.0815 g a.i.; Gaucho® teen 0.6125 g a.i. en Rovral® teen 0.9975 g a.i.). Die resultate het aangedui dat saadbehandeling (vir alle dosisse van SAkombinasie en die hoogste dosis van Cruiser) ontkieming en saailing groei vertraag, veral wanneer die saad onderwerp was aan die Versnelde Verouderings Toets. Glashuis studies met gepasteuriseerde grond by verskillende waterinhoude, saad bronne (stoor periodes) en plantdieptes, het die fitotoksiese effekte van die chemiese saadbehandelings bevestig in die afwesigheid van grondgedraagde patogene. Vanuit die resultate het dit duidelik geword dat ekstreme water toestande (baie nat of droog) die onderdrukkende effek op ontkieming en saailinggroei verhoog het, maar dat geen fitotoksiese reaksies plaasgevind het in klam (gunstige grondwater toestande) grond nie, ongeag die dosisse of chemikalieë gebruik, plantdiepte en saad bron. In 'n tweede glashuis eksperiment uitgevoer in klam grond (gehou by 50% van veldwaterkapasiteit om toksiese effekte te voorkom) van sewe lokaliteite wat natuurlik besmet was met patogene, was beide chemikalië effektief waar grondgedraagde patogene (Rhizoctonia so/ani en Pythium spp.) voorgekom het. Geen duidelike tendens is egter waargeneem vir enige van die chemikalieë of dosisse nie. Laastens is veldproewe uitgevoer om die effek van chemiese saadbehandelings op plant populasies en opbrengs te bepaal van canola geplant in verskillende rywydtes (17 en 34 cm) en saaidigthede (3, 5 en 7 kg.ha-1). Resultate het aangedui dat behandelde saad meer plante.rn" produseer en 'n groter opbrengs lewer as onbehandelde saad by Roodebloem Eksperimentele Plaas, terwyl die hoogste saaidigtheid betekenisvol meer plante.m" (Roodebloem en Langgewens Eksperimentele Plase), maar nie betekenisvol hoër opbrengste gelewer het as die laagste saaidigtheid by dieselfde lokaliteit nie. AI het rywydte nie 'n effek op plant populasie gehad nie, was opbrengs (Roodebloem 2003) betekenisvol minder by die wyer (34 cm) rye. Soos in vroeëre eksperimente is geen konsekwente verskille tussen die twee chemikalieë gevind nie. Hierdie resultate illustreer duidelik beide negatiewe (in die afwesigheid van grondgedraagde patogene) en positiewe (in die aanwesigheid van grondgedraagde patogene) effekte wat chemiese saadbehandelings op ontkieming, saailing groei en selfs opbrengs van canola onder plaaslike omgewings en grondtoestande kan hê. Omdat geen betekenisvolle verskille tussen die chemikalieë gevind is nie, moet beide chemikalieë as doeltreffend aanvaar word. Meer navorsing, veralonder veldtoestande en met meer kultivars, is egter nodig voordat die registrasie van 'n chemiese middel vir saadbehandeling oorweeg kan word.

Tobacco mosaic virus (TMV) is an economically important pathogen that has been studied for over one hundred years. Seedlings, seed coats, and nutrient solution were assayed for the presence of the virus and seed treatments were tested on seeds. Double antibody sandwich enzyme-linked immunosorbent assay (DAS ELISA) and biological local lesion assay data were collected. Seed coats from seed collected from TMV infected plants were always positive for TMV regardless of chemical treatment. Seed from infected source plants have lower germination than seed from healthy plants. Trisodium phosphate and hydrochloric acid treatments reduced virus infection of seedlings when grown under controlled conditions. Virus particles were serologically and biologically detected in both the leaves and roots of seedlings mechanically inoculated with TMV. Nutrient solution collected from 28 day old seedlings, 12 days post inoculation, tested positive for biologically active TMV by ELISA and infectivity assay. Infected water in float bed production could facilitate viral movement to all seedlings sharing nutrient solution. Seed transmission of TMV was shown to occur at a rate of 0.2%. This is in contrast to other research attempting to demonstrate seed transmission where visual symptoms on seedlings have been used to assess seed transmission.
Master of Science

Agriculture consistently remains one of the most hazardous industries. Hazards exist not only on farms, but also within pesticide manufacturers and distributors. Treating seeds with neonicotinoid insecticides is an important strategy to address pest problems. Neonicotinoids are a systemic insecticide that transfuse throughout the entire plant from roots to pollen. While research on the environmental effects of neonicotinoids is growing, research examining the potential adverse effects on humans is in its beginning phases. This pilot project provides an overview of the potential points of neonicotinoid exposure for manufacturers, distributors, and farmers who use seeds coated with neonicotinoid pesticides. A descriptive, cross-sectional study design was used to collect information characterizing occupational neonicotinoid insecticide handling practices at three different work environments: manufacturers of treated seed, distributors of treated seeds, and at farms where neonicotinoid treated seeds are planted. Potential participants were identified through internet searches of Iowa seed treating facilities and neonicotinoid treated seed distributors as well as snowball sampling for identification of farmers who used neonicotinoid treated seeds. Participants were interviewed at each worksite. Data were analyzed qualitatively by using a grounded theory approach to examine the written questionnaire responses, field notes, and photographs. The data were relatedly evaluated to identify themes, similarities, and differences between each work environment. Also, these facilities were examined for safety hazards associated with neonicotinoid insecticides during the tasks being accomplished at each site. The seed treatment sites visited during this project varied greatly in facility size, number of employees and building age. Larger facilities were more likely than semitrucks small facilities to report safety as a priority, and the age of the facility did not seem to affect the chance of exposure to neonicotinoids. The seed distributors studied during this project varied greatly in numbers of full-time and types of safety policies. The most thorough safety policies included an Emergency Action Plan, many different SOPs, yearly safety training, and having the seed treating equipment recalibrated at the start of each season. In addition, most distributors, at a minimum, wore gloves. All the farm workers interviewed planted corn and soy beans and used almost no PPE, with the exception of one farmer who reported wearing gloves while handling treated seeds. This pilot study provides suggestive evidence for a high potential of neonicotinoid exposure to workers at varying work environments. In order to quantify the range and magnitude of neonicotinoid exposures, future studies are needed that 1) expand the scope of the work environments examined; 2) comprehensively measure neonicotinoid concentrations in all potential exposure (e.g., inhalation, ingestion, dermal) pathways; and 3) perform biomonitoring of neonicotinoids.

The main objective of this research was to evaluate the effects of chemical treatment and ultrasound processing (sonication) on the fiber composition and rumen degradability of date palm seeds (DPS). For this purpose, five trials were conducted. In the first trial, the effects of treating DPS with 4% sodium hydroxide (NaOH) at different temperatures (23, 50 and 100 0C) and for different times (30, 60 and 356 min) on seeds fiber content and ruminal degradability were evaluated. Relative to untreated seeds, treated seeds had lower (P<0.05) lignin and hemicellulose, and greater (P<0.05) neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose content, particularly at high temperatures. The degradability of seeds organic matter (OM) and NDF were greater (P<0.01) in the treated (41.79 and 35.44%) than untreated seeds (24.71 and 22.77; respectively), particularly when incubated at 23 0C. Treatment time, however, had no effect (P>0.01) on seeds OM and NDF degradability.

Wyoming big sagebrush (Artemisia tridentata Nutt.) is an important native shrub in the Great Basin because of its wide distribution where it dominates over 60 million ha and provides essential habitat and forage for many varied species. The hand collection of sagebrush seed often results in seed scarcity and the available seed quantities are at times inadequate to revegetate large areas that have been disturbed, resulting in a demand for sagebrush seed. Study locations were selected near Scipio and Sahara sand dunes of Utah, and treatments were 1-) control, no treatment applied area left undisturbed 2-) general chemical strip thinning 3-) general chemical thinning of entire stand, 4-) general mechanical strip thinning, and 5-) general mechanical thinning of the entire stand. Significant differences among treatments in seed yields were collected in 2011 at Scipio but not at Sahara. At Scipio, the mechanical strip of competing sagebrush in 3m strips was the most effective of all treatment and produced 2.47kg/ha compared to 4.624kg/ha in the control, but the mechanical land area was only utilizing half the compared control area. The chemical treatments produced 1.819kg/ha and 1.31kg/ha. The percent of sagebrush mortality by each treatment determined the level of competition killed in treatment areas. All treatments at both locations killed at least 57% of the sagebrush. Chemical treatments had a consistent kill rate at both locations, although lower than anticipated, but mechanical kill was the highest at 93% in Scipio. Both mechanical and chemical treated plots had increased cover levels of cheatgrass when compared to the control plots.

Soybean has a strong demand for nitrogen that can be acquired from atmosphere for vegetative growth and seed production through the symbiosis with the soil bacterium Bradyrhizobium japonicum (B. japonicum). However, the native soil bradyrhizobia may be ineffective in nitrogen fixation and the greatest limiting factor in increasing symbiotic nitrogen fixation is the inability to influence the infection of soybean roots by a desired strain of B. japonicum due to competition from the native bradyrhizobia. Previous studies have demonstrated the efficacy of a co-inoculum seed treatment on the symbiotic competency of the soybean cultivar LS90-1920 in greenhouse and field trials. The co-inoculation by the soil bacterium Streptomyces kanamyceticus (S. kanamyceticus) strain ATCC 12853 and strains of B. japonicum more efficient in nitrogen fixation and resistant to the antibiotics kanamycin and neomycin may have an advantage over the native bradyrhizobia regarding soybean root infection (Gregor et al., 2003). However, inconsistent inoculation responses in field trials and low efficacy in nodule competency by selected Bradyrhizobium japonicum (B. japonicum) co-inocula were observed under greenhouse conditions. These results were attributed to insufficient population size or growth of viable co-inocula associated with the seed treatments. This recent study showed that the nodulation response of LS90-1920 to B. japonicum strains KNI-1 and KNI-3 is independent of the inoculum dose and age of the broth culture. Iron supplement to the inoculum nutrient solution significantly increased the total biomass of nodules formed by strain KNI-1 but not by strain KNI-3 on a per plant basis and had no effect on the nodule number regardless of B. japonicum strain. In the glass bead viability study, the effect of inoculum nutrient solution concentration on the viability of bacterial co-inocula is species-specific and influenced by seed coating material. The growth of Pseudomonas putida strains displayed a dependency on the concentration of the inoculum nutrient solution with graphite or vermicompost as the seed coating material treatment or with activated charcoal treatment associated with 0.1% or 1.0 % inoculum nutrient solution. The seed coating material treatments of vermicompost and graphite promote stronger growth of S. kanamyceticus strain ATCC 12853 than the activated charcoal treatment. After a six-day incubation at 28oC, a 1.0 % inoculum nutrient solution maintained the highest viable populations of co-inocula with activated charcoal and a 0.1% inoculum nutrient solution was most effective in the maintenance of the co-inocula population when graphite or vermicompost was employed as the seed coating material. By applying the appropriate level of inoculum nutrient solution, the viability of a selected B. japonicum KNI strain and co-inocula remained stable for six days in activated charcoal and graphite treatment regardless of the number of applied co-inocula. However, the vermicompost treatment did not maintain the viable populations of the B. japonicum KNI strains and P. putida strain G11-32 but support the vigorous growth of S. kanamyceticus strain ATCC 12853 and P. putida strain 17-29. Greenhouse studies employing sterilized vermiculite as a soybean growth medium showed no significant differences in nodule competency by the inoculum/seed coating treatments associated with B. japonicum strain KNI-1. However, the co-inoculum treatments significantly increased either the total nitrogenase activity (B. japonicum strain KNI-3 with S. kanamyceticus strain ATCC 12853) or the nodule number (B. japonicum strain KNI-3 with S. kanamyceticus strain ATCC 12853 and P. putida strain 17-29) versus the singular inoculum treatment of strain KNI-3. Soil-pot studies under the same greenhouse conditions showed no significant differences in the nodule competency between the inoculum treatment of B. japonicum strain KNI-3, the co-inoculum treatment of strain KNI-3 and S. kanamyceticus, and the non-inoculated control regardless of seed coating material. However, co-inoculation of emergence-promoting rhizobacteria (Pseudomonas putida strain 17-29 and G11-32) with strain KNI-3 and S. kanamyceticus strain ATCC 12853 may improve the total nitrogenase activity and specific nitrogenase activity, depending on the seed coating material and soil type. The treatment with activated charcoal employed as a seed coating material and the co-inocula of strain KNI-3, S. kanamyceticus strain ATCC 12853 and P. putida strains 17-29 or G11-32 showed significantly higher total nitrogenase activity (Stoy silt loam) and specific nitrogenase activity (Drummer silty clay loam) versus the non-inoculated control. For the Bethalto silty clay loam, the same co-inoculum treatment associated with graphite and vermicompost as the seed coating material significantly increased the total nitrogenase activity. The seed coating treatment by activated charcoal enhanced nodulation competency for both the 2010 and 2011 field trials resulting in higher grain yield, seed nitrogen content, and seed protein content versus the seed coating treatment by graphite. No significant differences by the inoculum treatments were determined.

Pumice and the Moringa oleifera (MO) seed were investigated as alternative natural materials for drinking water treatment based on problems identified at the Stretta Vaudetto water treatment plant in Eritrea.

Lab and pilot scale studies showed that pumice was a suitable alternative material for dual media filtration. Conversion of the sand filters at Stretta Vaudetto to pumice-sand media would significantly improve performance of the filtration units. The coagulant protein from the MO seed was purified in a single-step ion exchange purification method. The parameters for batch purification were optimized that can be readily scaled up. This will promote its use in water treatment.

A small volume coagulation assay method was developed that simplified and expedited the coagulation activity experiments. MO coagulant protein (MOCP) possessed considerable coagulation and sludge conditioning properties as alum. It also showed antimicrobial effects against bacteria, some of which are antibiotic resistant. The coagulation and antimicrobial properties of MOCP render it important in water treatment.

There is growing concern over the environmental and human health impacts of chemical contaminants in agricultural systems. The environmental persistence of veterinary antibiotics applied to agricultural fields during manure fertilization could lead to increased antibiotic resistance. New generation, neonicotinoid pesticides pose a threat to aquatic ecosystem health due high water mobility and increased potential for non-target exposure. The objectives of this research were to develop a sensitive, analytical method for quantification of pirlimycin (PLY) in soils to be used in field research and determine the ability of second-generation neonicotinoids to move through soil when applied as a seed coating using a greenhouse study. Liquid-solid extraction of PLY from soil using (1:6, v/v) ammonium hydroxide/methylene chloride produced good PLY recovery (67-140%). Liquid-chromatography coupled with tandem mass-spectrometry for instrumental analysis provided good sensitivity with minimal matrix interferences. The mass balance distribution of neonicotinoid treatment coated onto corn seeds was determined in plant and soil samples for a single pot after 3 weeks of growth. A large percent (83-87%) of initial pesticide coating applied to seed was un-detected in plant in soil. Of the detected portion of neonicotinoid treatment, between 96-98% was observed to move out into the soil. This suggests the potential for long-range transport of seed-coated neonicotinoids.
Master of Science

This thesis investigates the evolution of medical responses to tuberculosis in England between 1940 and 1974. Set against the backdrop of the reorganisation of health care in 1948, it uses case material from the West Midlands to expose how changing national, regional and local circumstances influenced disease prevention and treatment strategies in an under-researched timeframe. Chapter 1 explores the use of BCG vaccination as a tuberculosis prevention measure, within the context of the national and international debates over its efficacy. After analysing the impact of the mass vaccination programme of schoolchildren in one local authority area, Dudley, it is concluded that in this locality, BCG vaccination made at best a marginal contribution to tuberculosis prevention during the 1950s and 1960s. The aim of mass radiography, introduced during World War 11, was to detect early, asymptomatic cases of tuberculosis by taking a miniature X-ray of the chest. Chapter 2 examines the operation of the mass radiography service in the West Midlands, and argues that this was a flawed preventive initiative, which diverted resources away from those with symptoms of disease. However, when operated as a diagnostic service to GPs, it supplemented scarce resources in the most populated parts of the region. The treatment of tuberculosis underwent rapid metamorphosis during the 1950s. However, the standard rhetoric of the success of chemotherapy, linked to Medical Research Council trials of streptomycin, masks the history and success of two other treatment methods, bed rest and surgery. The inter-relationship between these three treatment strands, and the complexities of treatment choice, are explored in Chapter 3. Research into tuberculosis in the recent past has focused on cultural and social aspects of disease history, or on inter-disciplinary themes. Through its concentration on medical efforts to prevent and treat tuberculosis in the middle years of the twentieth century, this thesis makes a distinctive contribution to existing historiography.

The utilization of cover crops and no-till practices are important for the conservation of both soil and moisture in South Dakota. However, it is unknown if these practices impact the efficacy of insecticide seed treatments. In soybean, insecticide seed treatments are used prophylactically to prevent potential crop losses from early season insect pests. The prophylactic use of any management strategy increases the likelihood for selection pressure and also represents unnecessary input costs. The purpose of the research conducted for Chapter 2 was to determine the impact that tillage systems, cover crops and planting populations have on the efficacy of insecticide seed treatments. Two years of field data was collected from established long-term tillage and cover crop rotation plots at the South Dakota State University Southeast Research Farm. During each year, four factors were evaluated for their impact on yield (i.e., tillage, cover crop, seeding rate and seed treatment). Stand counts, soil samples and yield data were taken from each plot. In Chapter 3, we evaluated pyrethroid resistance in soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) populations in South Dakota. In 2015, the University of Minnesota discovered populations of the soybean aphid that were partially resistant to pyrethroid insecticides. Due to the soybean aphid’s capacity for rapid reproduction and its ability to travel long distances in its alate (i.e., winged) form, it was determined that South Dakota may have resistant populations present. In 2017 and 2018, an efficacy study was deployed at three locations, over two years throughout Eastern South Dakota. A total of eight foliar insecticides were used in 2017 and 10 foliar insecticides in 2018. The results from chapter 2 indicate that seed treatment and cover crops have no significant impact on soybean yield. The results from chapter 3 determined that pyrethroid resistant soybean aphids are present in South Dakota.

Fusarium virguliforme, the causal agent of sudden death syndrome (SDS) in North America, and Heterodera glycines, soybean cyst nematode (SCN), are significant threats to the production of soybean. In 2014, two field trials were established to evaluate seed treatments and their efficacy in managing SDS and SCN. The locations were selected because each has a history of SDS and SCN. Plots were 3.04 meters wide by 6.1 meters in length with row spacing of 0.76 meters. Each plot received 2.45 grams of infested sorghum per 30.5 centimeters of row. At each location, two soybean varieties and ten different seed treatments were tested in 2014. In 2015, twelve seed treatments were tested on the same two varieties at the same two locations. Seed treatments were evaluated for phytotoxicity, vigor, stand count, SDS foliar ratings and soybean yield. Soil samples were collected at planting and at harvest to determine SCN reproduction. Root samples were collected from each plot to quantify the amount of F. virguliforme DNA in the soybean roots using a real-time quantitative polymerase chain reaction (qPCR) protocol. ANOVA and Fisher’s LSD Test were used to separate treatment means. Analysis of the qPCR was done by comparing the quantification cycle (Cq) values and separating means using ANOVA. There were significant differences between varieties for soybean yield and disease index. Treatments containing fluopyram had more phytotoxicity than treatments lacking fluopyram at both locations. Several treatments allowed for higher SCN reproduction than treatments with Clariva. At Ina, a fluopyram treatment and one of the Clariva treatments had higher soybean yield than the non-treated control. At Shawneetown, one fluopyram treatment had higher soybean yield than all other treatments. In the qPCR analysis, seed treatments with fluopyram had a lower amount of F. virguliforme DNA in the roots than the non-treated control.

Biliverdin IXα is a green bile pigment produced by enzymatic cleavage of a tetrapyrrole ring of heme by heme oxygenase. While biliverdin IXα is emerging as an effective cytoprotectant, the conventional method for producing biliverdin IXα by chemical conversion of animal bile is not suitable for large scale production. A novel scalable production method was pursued via bacterial fermentation. Recombinant Escherichia coli strains were obtained by sequence optimization and plasmid transformation of a cyanobacterial heme oxygenase gene. Further strain development was done by plasmid overexpression of a native E. coli flavodoxin gene as a possible electron donor for heterogeneous heme oxygenase. The resulting strains were grown in a fed-batch culture system optimized for biliverdin IXα production. Syringomycin E is a lipodepsinonapeptide produced by certain strains of Pseudomonas syringae pv. syringae by nonribosomal peptide synthesis. Though syringomycin E had been considered a phytotoxin in the past, recent research results indicate that syringomycin E is a natural fungicide that is not toxic to animals and plants. Syringomycin E is a potential fungicide especially for use in the organic agriculture sector. New strains of P. syringae pv. syringae were isolated through ultraviolet mutagenesis and screenings for enhanced capability to produce syringomycin E especially under agitated conditions. Fermentative production was conducted in a newly formulated medium and the product was purified through a large scale chromatography system using organic-compatible solvents. Purified syringomycin E was tested on cucumber seeds to examine its antifungal activity against a soil-borne pathogen Pythium ultimum. Syringomycin E was able to inhibit Pythium infection and protected seeds and seedlings without developing disease symptoms. This dissertation research showed scalable production of two natural products, biliverdin IXα and syringomycin E in bacterial platforms. Strain development by gene recombination and mutation was done to obtain bacterial strains capable of overproducing desired metabolites. The resulting strains were grown in fermenters to maximize the yields under agitated conditions. Monitoring growth parameters and medium modifications were critical to achieve large scale production.

In the light of growing concern over greenhouse gas emissions and limited fossil fuels, the use of renewable energy sources such as biomass is becoming more vital. Jatropha curcas seed cake, which is a waste product of biodiesel production, has been identified as a potential candidate to be co-fired with coal in existing boilers. There is a dearth of information on the effective utilisation of Jatropha curcas seed cake in this manner, and this research work contributes to bridging this knowledge gap. The seed cake received was divided into two distinct classes based on appearance and texture, identified as type A (harder and lower oil content) and type B (the more abundant class). As an initial step, the fundamental fuel properties of the seed cake were determined; these include the proximate and ultimate analyses, higher heating value (HHV) and inorganic content. The HHV of type A and type B was 20.76 MJ/kg and 24.06 MJ/kg, respectively; their dry ash content was 5.9% and 4.4%, respectively. K was the most abundant inorganic element present. The main hindrances to co-firing of a typical biomass with coal arise due to the difference in properties of biomass and coal. Torrefaction and leaching were carried out with the aim of bringing the thermochemical (primarily the HHV) and chemical (inorganic content) properties, respectively, of the seed cake closer to those of coal. An envelope of torrefaction conditions was recommended –~250°C for 45-60 min for the type A, and < 5 min at > 280°C to > 45 min at 220°C-250°C for the type B. These conditions ensured that the HHV of the type A and type B were enhanced to > 24.5 MJ/kg and > 27 MJ/kg, respectively, while not compromising excessively on the energy yield. Leaching at 20°C for < 24 h was considered adequate in the case of the untorrefied seed cake, and this result ed in a reduction of the potassium content (the most abundant and critical inorganic element in the seed cake) by 85%. Leachability of the torrefied biomass was markedly reduced, and leaching at least at 50°C was deemed necessary. Combustion modelling using Ansys Fluent 14.0 was carried out to assess the combustion and co-firing characteristics of untorrefied and torrefied Jatropha curcas seed cake. The effect of torrefaction on the devolatilisation characteristics, flame properties and consequently NOx pollutant formation was established. Compared to the torrefied biomass, the untorrefied seed cake devolatilised earlier, had a more dispersed flame and higher NO formation. The higher reactivity of the biomass was shown to have a positive effect on the devolatilisation rate of the less reactive coal under co-firing simulations.

ZELNÍČKOVÁ Marta: Optimizing of heat treatment of casting produced by SEED method. This work deals with designing optimum heat treatment method for casting alloy AlSi7Mg0,3, cast by SEED. Different temperature and times are tested in regimes of heat treatment, mechanical properties are determined with dependence of on the heat treatment method and optimal temperature regime is determined from the detected values.

Sixty-six isolates of F. oxysporum and F. solani were recovered from healthy and necrotic Essex soybean seedlings grown in naturally infested soil. These were tested for pathogenicity at 20 C and -0.01 MPa water potential in artificially infested, autoclaved field soil. Highly pathogenic, moderately pathogenic, and hypovirulent isolates of both species were identified. Fifty-seven F. oxysporum and nine F. solani isolates were tested for the presence of dsRNA. The presence of dsRNA was not associated with hypovirulence in F. oxysporum since some hypovirulent isolates contained dsRNA while other hypovirulent isolates did not. Furthermore, of six dsRNA-containing F. oxysporum isolates, three were hypovirulent, two were moderately pathogenic, and one isolate was highly pathogenic. Four segments of dsRNA, with sizes of 4.0, 3.1, 2.7, and 2.2 kb, were detected in extracts of all six F. oxysporum isolates. No morphological differences were found between dsRNA-containing and dsRNA-free F. oxysporum isolates. Attempts to cure dsRNA-containing hypovirulent F. oxysporum isolates, either by single-sporing of isolates or by using a range of concentrations of cycloheximide, were not successful. No dsRNA was found in any of the F. solani isolates tested. Pythium ultimum, an associate in Essex seedling disease, was isolated from water-soaked lesions and interfered with evaluations of disease caused by the Fusarium spp. Metalaxyl was used to control P. ultimum and had no apparent effect on symptoms associated with F. oxysporum and F. solani in field soil. Prior inoculation of Essex soybean seeds with conidia of dsRNA-free hypovirulent F. oxysporum isolates, plus metalaxyl seed treatment, significantly (p<0.05) reduced disease severity on both cotyledons and hypocotyls and increased the rate of seedling emergence in field soil, compared to the control plants treated with metalaxyl alone or not treated with metalaxyl. No significant (p>0.05) differences were found between dsRNA-containing and dsRNA-free hypovirulent F. oxysporum isolates in their effects on the reduction of disease severity. A mixture of two hypovirulent F. oxysporum isolates was significantly (p<0.05) more effective than single hypovirulent F. oxysporum isolates in increasing the rate of seedling emergence. Symptoms associated with P. ultimum were not affected by the prior inoculation of seeds with individual hypovirulent F. oxysporum isolates.
Master of Science

Developing countries pay a high price for water treatment due to importation of water treatment chemicals. Today, more than 663 million people lack access to a clean water supply which results in many deaths. Hibiscus plant seeds, namely Okra, Sabdariffa and Kenaf were investigated to identify their suitability as alternative water treatment materials to provide clean water supply to people in developing countries. Coagulation and disinfection ability of the extracts were assessed using a jar tester and Collilert-18 Quanti-Tray methods whereas dissolved organic carbon (DOC) test was performed using Shimadzu TOC analyser. The results of this work revealed that all the seed samples possess an anionic coagulant protein with a low molecular weight of 39 kDa. The potential of the seeds in crude form was clearly demonstrated, albeit with some issues regarding organic nutrient addition to the clarified water. However, this challenge was overcome by purifying the seed proteins in an ion exchange column where the impact of DOC addition was significantly reduced in the treated water, as demonstrated via fluorescence excitation-emission matrices. Additionally, the coagulant proteins identified in the region of tryptophan-like fluorescence were found to be stable after heat treatment. Furthermore, sludge production using seed extracts was found to be 5 times lower than that of aluminium sulphate (AS) and the pH of the treated water remained largely unaffected after treatment. Floc strength tests, undertaken using a laser diffraction instrument Mastersizer 2000, showed that the use of seeds as coagulant aids in combination with AS improved floc properties, leading to faster floc growth and shorter coagulation time.

The Pasteuria genus comprises gram-positive bacteria that are obligate parasites of arthropods and nematodes. Species of this genus are ubiquitous, being present in both aquatic and terrestrial environments all around the world. Pasteuria was first described as a genus at the end of the 19th century and has undergone considerable reclassification regarding its member species. Starting in the 1980s, a more meticulous classification effort regarding the identification of Pasteuria spp., and its parasitic habits began. These studies were strongly motivated by the ability of individuals of this genus to parasitize phytopathogenic nematodes of several plant species. Each species of the genus Pasteuria establishes a strict parasitic relationship with a specific genus of phytonematode. As an example of this interaction, Pasteuria thornei is a parasite restricted to the genus Pratylenchus, which comprises the nematodes popularly known as root-lesion-nematodes, a pest of several agronomically important crops. Considering the current relevance of studies involving the biological control of phytonematodes, in the present work three experiments were carried out, each one containing a replicate, totaling, therefore, six experiments. Two experiments were intended to verify the efficacy of P. thornei as a biological control agent (BCA) of Pratylenchus brachyurus in soybean. The remaining four experiments had a similar objective in the scope of the Pratylenchus zeae - maize pathosystem. Two experiments were carried out to verify the efficacy of P. thornei as a biological control agent for P. zeae in maize, and afterwards, two additional experiments were performed in order to verify the capacity of the BCA to reduce productivity losses in corn plants due to the parasitism of this nematode. For the soybean experiments, the following treatments were added to the seeds of the cultivar SYN1080: three different concentrations of P. thornei endospores per seed (5x106, 107 e 1,5x107), a commercial control group for comparison containing abamectin (0.58mg/seed) and a mixed treatment containing abamectin (0.58 mg / seed) and 107 P. thornei endospores. Untreated seeds were used as a control group. The treatments were sown in 500 cm3 plastic cups containing soil inoculated with 1000 nematodes (experiment 1) and 600 nematodes (experiment 2). Fresh root mass and nematodes extracted from the roots of each plant were used as parameters of evaluation, taking place 60 and 90 days after inoculation (DAI). Only the treatment with the highest concentration of P. thornei (1.5x107) reduced the final population of nematodes significantly, reaching 30-50% of reduction compared to the untreated seeds. However, treatments containing the commercial control abamectin were superior in reducing the final population of nematodes in all experiments evaluated. Regarding the maize efficacy experiments, CELERON hybrid seeds were treated as described: four concentrations of P. thornei endospores per seed (5x106, 107, 1,5x107, 2x107), a commercial control group for comparison containing abamectin (0.58 mg / seed) and a mixed treatment containing abamectin (0.58 mg / seed) and 107 P. thornei endospores. Untreated seeds were used as a control group. The treated maize seeds were planted in 500 cm3 plastic cups containing soil inoculated with 4000 and 1000 individuals for the efficacy experiments 1 and 2, respectively. Evaluations occurred at 60 and 90 DAI. For the productivity assays, the experiments 3 and 4 were carried out under a screened greenhouse, with experimental plots consisting of 9L pots filled with artificially infested soil. Seeds of the CELERON hybrid received the following treatments: abamectin (0.58mg / seed), P. thornei (107 endospores / seed) and mixed treatment containing both abamectin (0.58mg / seed) and P. thornei (107 endospores / seed). Two additional treatments containing untreated seeds served as controls, with and without the presence of Pratylenchus zeae. The evaluation measured several agronomic traits, such as dry weight of the aerial parts, fresh mass of roots at harvest and total weight of grains. In addition, the nematode population was measured in fresh roots at 45, 90 days and at the time of harvest. Efficacy trials showed that the highest concentrations of P. thornei (1.5x107 and 2x107) have a considerable potential of P. zeae control. The nematode population reduction was 54 and 47% in experiments 1 and 2, respectively, for the highest P. thornei concentration treatment. The commercial formulation containing abamectin showed a reduction of P. zeae population above 90% in both experiments. Regarding the maize productivity experiments, control potential of nematodes by P. thornei was similar to that observed in the efficacy study. The treatments containing abamectin had an effect on the mitigation of yield losses caused by P. zeae in both experiments. The mixed treatment (abamectin and P. thornei) and the one containing exclusively P. thornei presented a positive performance in both replicates. In none of the experiments synergistic or additive effects were observed between P. thornei and abamectin. With the data obtained in these experiments, the control potential of P. thornei on P. brachyurus and P. zeae in soybean and corn, respectively, is evident. Additionally, P. thornei and abamectin in the form of seed treatment, show potential in mitigating yield losses caused by P. zeae in maize. This highlights the importance of P. thornei as an additional tool for the management of root lesion nematodes in soybean and maize, and should encourage subsequent work.
O gênero Pasteuria compreende bactérias gram-positivas parasitas obrigatórias de artrópodes e nematoides. A distribuição das espécies deste gênero pelo mundo é ubíqua, podendo ser encontradas em ambientes aquáticos e terrestres. Este gênero foi descrito no final do século XIX e sofreu consideráveis reclassificações em relação às espécies nele compreendidos. A partir da década de 80, deu-se início a um esforço de classificação mais minucioso com relação à identificação de Pasteuria spp. e seus hábitos parasitários. Estes estudos foram motivados, principalmente, pela capacidade dos indivíduos deste gênero em parasitar nematoides fitoparasitas de diversas culturas. Cada espécie do gênero Pasteuria estabelece relações parasitárias com um gênero específico de fitonematoide. A exemplo desta interação, Pasteuria thornei é um parasita restrito ao gênero Pratylenchus, que compreende os nematoides causadores das lesões radiculares, daninhos a diversas culturas de importância agronômica. Considerando a relevância atual de estudos envolvendo o controle biológico de fitonematoides, no presente trabalho foram realizados três experimentos, cada um contendo uma réplica em época distinta, totalizando, portanto, seis experimentos. Dois experimentos tiveram por objetivo verificar a eficácia de P. thornei como agente de controle biológico (ACB) de Pratylenchus brachyurus na cultura da soja. E os demais quatro experimentos abordaram o patossistema Pratylenchus zeae-milho. Para esse objetivo, foram realizados dois experimentos com o intuito de verificar a eficácia de P. thornei como agente de controle biológico de P. zeae em milho, e outros dois experimentos para testar a capacidade do ACB em reduzir a perda de produtividade em plantas de milho decorrente do parasitismo do nematoide. Para os experimentos de soja, às sementes da cultivar SYN1080 foram adicionados os tratamentos como se segue: três concentrações de endósporos de P. thornei por semente (5x106, 107 e 1,5x107), um grupo de controle químico comercial para comparação contendo abamectina (0,58 mg / semente) e um tratamento misto contendo abamectina (0,58 mg / semente) e 107 endósporos de P. thornei. Sementes não tratadas foram utilizadas como testemunha. As sementes tratadas foram semeadas em copos de plástico de 500 cm3 contendo solo inoculado com 1000 nematoides (experimento 1) e 600 nematoides (experimento 2). A massa de raiz fresca e os nematoides extraídos das raízes de cada planta foram utilizados como critério de avaliação dos experimentos, a qual foi realizada aos 60 e 90 dias após a inoculação (DAI). Apenas o tratamento com a maior concentração de P. thornei (1,5x107) reduziu a população final de nematoides de maneira significativa atingindo 30-50% de redução, comparado àquele contendo sementes não tratadas. No entanto, os tratamentos que contém abamectina foram superiores na redução da população final de nematoides em todos os experimentos avaliados. Em relação aos experimentos de eficácia em milho, sementes do híbrido CELERON foram tratadas como explicitado: quatro concentrações de endósporos de P. thornei por semente (5x106, 107, 1,5x107 e 2x107), um grupo de controle comercial para comparação contendo abamectina (0,58 mg / semente) e um tratamento misto contendo abamectina (0,58 mg / semente) e 107 endósporos de P. thornei. As sementes tratadas de milho foram semeadas em copos de plástico de 500cm3 contendo solo inoculado com 4000 e 1000 indivíduos para os experimentos de eficácia 1 e 2, respectivamente. As avaliações ocorreram aos 60 e 90 DAI. Para os estudos de produtividade, foram realizados os experimentos 3 e 4 sob um telado com parcelas experimentais constituídas por vasos de 9L preenchidos de solo infestado artificialmente. Sementes do híbrido CELERON foram utilizadas contendo os seguintes tratamentos: abamectina (0,58mg / semente), P. thornei (107 endósporos/semente) e um tratamento misto contendo abamectina (0,58mg / semente) e P. thornei (107 endósporos/semente). Dois tratamentos adicionais contendo sementes não tratadas serviram de testemunhas, com e sem Pratylenchus zeae. A avaliação consistiu na medição de várias características agronômicas, como peso seco da parte aérea, massa fresca de raízes no momento da colheita e peso total dos grãos. Adicionalmente, foi mensurada a população de nematoides em raízes frescas aos 45, 90 dias e no momento da colheita. Os ensaios de eficácia mostraram que as concentrações mais elevadas de P. thornei (1,5x107 e 2x107) possuem um potencial mensurável de controle de P. zeae. A redução da população de nematoides foi de 54 e 47% nos experimentos 1 e 2, respectivamente. A formulação comercial de abamectina mostrou uma redução da população de nematoides superior a 90% em ambos os experimentos. No que diz respeito aos experimentos de produtividade de milho, o potencial de controle de nematoides por P. thornei foi semelhante ao observado no estudo de eficácia. O tratamento com abamectina teve efeito na redução das perdas de rendimento causadas por P. zeae em ambos os experimentos; assim como os tratamentos misto (abamectina e P. thornei) e aquele contendo apenas P. thornei que apresentaram desempenho positivo em ambas as repetições. Em nenhum dos experimentos foi observado efeito sinérgico ou aditivo entre P. thornei e abamectina. Com os dados obtidos nestes experimentos, fica evidente o potencial de controle de P. thornei sobre P. brachyurus e P. zeae em soja e milho, respectivamente. Ainda, tanto P. thornei quanto abamectina apresentam o potencial de mitigar as perdas de rendimento causadas por P. zeae em milho através do tratamento de sementes. Isso evidencia a importância de P. thornei como uma ferramenta adicional para o manejo desses nematoides, e deve encorajar trabalhos subsequentes.

Seed transmission of Cylindrocladium parasiticum was investigated as a possible explanation for the higher-than-expected incidence of Cylindrocladium black rot (CBR) of peanut in fields fumigated with metam sodium. Sixty-three commercial seed lots from Virginia production fields were examined for the presence of seed with speckled testae, a symptom of seed infection by C. parasiticum. Speckled seed was present in conditioned seed lots in 1998, 1999, and 2000 at an average rate of 1%. Soon after pods were harvested, the fungus was recovered from speckled seed at high frequencies. During winter seed storage, pathogen survival remained high in seed stored at -13 and 4 C, but declined in some seed stored at 15 C and ambient temperatures. Speckled and normal seed with and without fungicide treatment was planted in steam-treated soil in the greenhouse and metam-treated field plots in 1999 and 2000. Speckled seed treated with captan + pentachloronitrobenzene (pcnb) + carboxin transmitted the pathogen to emerging plants in the greenhouse and field. Transmission levels depended on the amount of viable inoculum present in seed at the time of planting. In the field, yield losses were significant when 20% or more of the seed planted was speckled. The low incidence of speckled seed in commercial seed lots would not result in a loss of yield for growers, but may contribute to disease spread. Testing of additional seed treatment fungicides indicated that fludioxonil, tebuconazole, and thiram may offer the best protection against disease spread from seed transmission of C. parasiticum.
Master of Science

Natto and sprout soybeans are produced using small-seeded soybeans and their production is a high value alternative to grow grain soybeans for food in U.S. The development of soybean cultivars with improved natto and sprout quality is crucial for maintaining and increasing the soyfood market. However, there is insufficient information on sprout soybean characteristics. Therefore, the first objective of this study was to evaluate seed and sprout traits as potential selection criteria and study the storage effect on sprout quality. Seeds can be a vehicle for transmission of pathogens capable of causing human illness. That is why, the second objective was to identify seed-borne pathogens on a commercial soybean cultivar and to evaluate different seed decontamination treatments. Finally, seed coat deficiency is an undesirable trait for natto soybean seeds because it causes inferior appearance of the product. Thus, the third objective was to identify quantitative trait loci (QTL) underlying seed coat deficiency (SCD) and associated markers. Results showed that seed size, high-, average- and low-quality sprout percentage, hypocotyl thickness and length and sprout yield are the most important variables for breeding sprout cultivars; and one-year seed storage at room temperature reduced sprout quality. Fusarium, Alternaria and Diaphorte were the most frequent genera isolated from soybean seeds, and 2% calcium hypochlorite and 5% acetic acid were promising seed disinfection treatments. A stable QTL, qSCD20_1, was identified across two years explaining up to 25% of the variation of SCD; and eight molecular markers tightly linked and nearby qSCD20_1 were identified. Information presented will be helpful for sprout and natto soybean cultivar development.
Master of Science

Dectes texanus LeConte (Coleoptera: Cerambycidae) is a longhorn beetle species endemic to eastern United States. Originally described as a pest of weeds from the family Asteraceae, D. texanus has expanded its host range and is found infesting the stems of soybeans, Glycine max (L.) through the southwestern and middle United States. Female D. texanus chews a hole in the epidermis of a petiole and oviposits on it. Then, the D. texanus larva depletes all the pith of the stem making a tunnel down to the base of the plant and girdle the stem about 5 cm above the soil line. When a force is applied to the girdling point, generally weather related (i.e. strong winds), the plant lodges. While D. texanus phenology has been described for some states, this topic has yet to be explored in Kentucky. The objectives of this study were: 1) to describe the life cycle and behavior of D. texanus in soybeans in Western Kentucky, 2) to study the effect of the stem diameter on the incidence of D. texanus infestations, 3) to evaluate the susceptibility of full-season and double-crop soybeans to D.texanus infestations, 4) investigate the efficacy of seed treatment in reducing D. texanus infestations, 5) to determine effects of D. texanus larval feeding in the physiological yield of soybeans. The results of these studies showed that: 1) there was no distinct peak of D. texanus emergence detected in the 2018 and 2019 growing seasons and pupation period varied with year and location; the best sampling period for D. texanus population should occur between 1000 and 1600 hours during the peak season with either a 5-gallon white plastic bucket or sweep net; 2) the probability of finding D. texanus infesting soybeans was higher when the stem diameter is larger than 9 mm, and smaller than 11 mm; 3) double-crop soybeans had reduced infestations of D. texanus because these soybean plants are not a suitable host when D. texanus was active ovipositing and the pith was not fully developed; 4) seeds treated with imidacloprid did not influence D. texanus infestation on soybeans, larvae presence in main and lateral stems, and parasitism occurrences; and 5) D. texanus did not affect seeds and pods attributes (pod width, length, height and weight), and yield. The latter may occur because feeding of D. texanus larva does not interfere on photosynthesis or nutrient transportation during seed fill.

The response of several plant species to heavy metal contaminated soils was evaluated using plant bioassays with a soil substrate. A natural soil was collected from Dinwiddie County, Virginia and soil analysis was performed. The plant species, Lolium multiflorum, setaria italica and Trifolium rep ens latum, Robinia pseudoacacia, Andropogon gerardi, Asclepias syriaca, Echinacea purpurea, Rudbeckia hirta and Festuca rubra were grown in to determine the response to cupric and cadmium chloride in soils (mg Cu/kg soil). A few plant species were grown in small pots in a plant growth chamber for 28 days using control, 10, 30, 100 and 300mg Cu or Cd/kg soil. Germination proved to be less sensitive than root length. S. italica had highest ECSOs. In eu 20.7 and 15.3 in Cd. All plant species were grown for 7 days in 0.3, 1.0, 3.0 10.0, and 30.0mg Cu/kg soil and in control. Germination was not effected by metal concentrations in most species (p=0.07-0.6), except T.repens latum, R. hirta and F. rubra at 30mg/kg (p=0.0007). Root length was significantly effected by Cu concentrations for almost all species (p=0.0001-0.0112). Setaria italica had the highest EC50 at 10.86mg/kg. Robinia pseudoacacia root length was not significantly affected by CU concentrations. The other species had EC50s ranging from 3.74-7.51mg/kg. Both inhibition and stimulation of root growth were observed.

Preliminary studies regarding germination rates, fungicides and rangefinding are included.
Master of Science

The aim of this master thesis study was improvement of the required operational conditions for aerobic granulation in sequencing batch reactors (SBRs). In the first part of the study, membrane bioreactor sludge (MBS) and conventional activated sludge (CAS), were used to investigate the effect of suspended seed sludge type on granulation in SBRs. The MBS granules were found to be advantageous in terms of size, resistance to toxic effects, stability and recovery compared to CAS granules. During non-inhibitory conditions, sCOD removal efficiencies were 70±
13% and 67±
11% for MBS and CAS, and total nitrogen (TN) removal efficiencies were 38±
8% and 26±
8%, respectively. In the second part of the study, the effects of period sequence (anoxic-aerobic and aerobic-anoxic) on aerobic granulation from MBS, and sCOD, N removal efficiencies were investigated. Granules developed in anoxic-aerobic period sequence were more stable and larger (1.8-3.5 mm) than granules developed in aerobic-anoxic sequence. Under steady conditions, almost 95% sCOD, 90% Total Ammonia Nitrogen (TAN) and around 39-47 % of TN removal was achieved. Almost 100% denitrification in anoxic period was achieved in anoxic-aerobic period sequence and it was observed around 40% in aerobic-anoxic period sequence. The effects of influent sulfate (from 35.1 mg/L to 70.2 mg/L) on treatment efficiencies of aerobic granules were also investigated. The influent SO42- concentrations of 52.6 mg/L to 70.2 mg/L promoted sulfate reduction. The produced sulfide (0.24 mg/L to 0.62 mg/L) inhibited the ammonia-oxidizing bacteria (AOB) performance by 10 to 50%.