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Prolonged exposure to high ambient temperature without cooling causes heat stress (HS) resulting in altered growth, body composition and metabolic dysfunction in pigs. Grape seed extract (GSE) has been shown to reduce inflammation, and improve glucose transport and metabolism. Thus, GSE may be an effective supplement to combat the consequences of heat stress; however this possibility has not been evaluated in a large animal model. The objective of the current study was to examine the effect of GSE supplementation on pig performance and body composition during HS. Twenty-four female pigs (62.3± 8 kg BW) were randomly assigned to a 2X2 factorial experiment; thermal neutral (TN; 21-22°C) or heat stress conditions (HS; 33-34°C) for 7 days and fed either a control or a GSE supplemented diet (12mg/kg body weight). Body temperature (TB), respiration rate (RR) and feed intake (FI) were measured daily. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Respiration rate and TB increased in the HS control group compared to the TN control group (p<0.05), however GSE did not alter these parameters compared to control for the duration of the 7 day period. HS decreased FI (P < 0.05). Fasting blood glucose concentrations were approximately 1.5-fold greater in the control diet compared to their GSE supplemented counterpart (p=0.067) on day 6 of the HS period, but did not differ between groups at the end of day 7 of HS. Body composition analysis indicated bone mineral density, bone mineral content, and percent change of fat remain unchanged between treatment groups. Percent change in weight was significantly reduced in HS. Lean tissue accretion was 45% greater in TN compared to HS groups (p<0.05). Endotoxin concentrations were approximately 2-fold lower in the HS-GSE group compared to the control (P=0.083). Grape seed extract supplementation does not appear to alter pig growth performance or body composition, but does appear to delay the onset of reduced feed intake by 1 day, reduce intestinal permeability, and improve insulin sensitivity during additional stress. / Master of Science in Life Sciences

Batch inoculation of legume seeds by commercial companies would remedy many of the difficulties encountered in getting proper and uniform inoculation by all planters. From the results of this investigation, which was to test the feasibility of commercial inoculation, the following statements appear to be justified. 1. Inoculated <i>Rhizobia</i> may remain on their specific legume seed when stored at 5°C at least 11 months in numbers greatly exceeding those required for good nodulation. 2. Sterilization of the seed before inoculation was not necessary in the experiment because of the low total organism count on the seed and because precautions were taken to check the identification of the test organisms. 3. Those treated legume seeds stored at 5°C had greater numbers of viable <i>Rhizobia</i> at 2, 3, 4, 5, and 6 months than the same treatments stored at room temperature for the same length of time. 4. It appeared that the amount of moisture present during storage is an important factor in the survival of the organisms regardless of storage temperature. 5. The <i>Rhizobia</i> on seeds inoculated with a suspension of the organisms in one per cent gum tragacanth solution withstood the desiccation and storage to a higher degree than organisms inoculated onto the seed suspended only in a water medium. 6. In the third month microscopic colonies ranging from 0.05mm to 0.15mm were observed on the various plates of each treatment. The significance of these small colonies is not known. 7. When the stored inoculated seed was sprouted and grown under otherwise sterile conditions, it was found that although the average number of organisms per seed varied considerably for the various seed treatments, there was no significant difference between the average nodules produced per plant for the same treatments. The results of this thesis definitely indicate the feasibility of commercial inoculation of legume seed. It would be necessary, however, to work out certain details previously discussed in this paper before such inoculation could be attempted commercially. / Master of Science

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 / 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.

The decline in range and density of frugivorous birds worldwide could have consequences for the functioning of ecosystem processes such as seed dispersal. I endeavoured to determine the effects of bird declines on seed dispersal and assess the current status of dispersal in New Zealand. My first aim was to determine whether decreased bird density can reduce competitive interactions between birds, leading to birds concentrating on higher-reward fruit species. I measured fruit removal rates and fruit preferences of birds in Canterbury forest remnants with high (Hay and Prices) and low (Lords and Kaituna) bird densities. Removal rates of Melicytus ramiflorus and Coprosma spp. were lower at low-bird sites, and the size of this effect was greater for low-reward plant species. Coprosma areolata (a low-sugar fruit) had limited dispersal at Kaituna (59% fruit removed by end of 2012 season), compared with 92% removal at Hay, whereas 99-100% of M. ramiflorus and C. robusta (higher-sugar) fruits were removed at both sites. My second aim was to determine whether seed dispersal by introduced possums (Trichosurus vulpecula) can compensate for bird declines. I analysed seeds present in possum and bird faecal samples collected at Kowhai Bush, Kaikoura. Possums dispersed <3% of the total seeds, much less than bellbirds (21%), silvereyes (16%), song thrushes (33%) and blackbirds (28%). Possums also destroyed approximately 15% of seeds found in faeces, reduced the germination of gut-passed C. robusta seed to half of that from bird faeces (30% vs. 60-70%), and did not swallow fruits any larger than those moved by the much smaller birds (c. 7 mm diameter). My third aim was to determine the relationship between percentage of fruits dispersed and distance from parent tree for three large-seeded trees; Beilschmiedia tawa, Elaeocarpus dentatus, and Prumnopitys ferruginea. I fitted dispersal kernels to the observed dispersal distances out to 50 m for both undispersed whole fruits and seeds consumed by a bird, and found that dispersal quantity below the parent tree strongly underestimates total dispersal quantity. The average percentage dispersed overall was 81% for B. tawa, 75% for E. dentatus and 91% for P. ferruginea, and for all species finding only 11-18% clean seeds under the parent tree would correspond to an overall percent dispersed of at least 50% of the whole seed crop. My final aim was to determine the consequences of dispersal failure for recruitment in three plant species; Elaeocarpus hookerianus, Ripogonum scandens, and C. robusta. I compared the fate of dispersed and undispersed seeds in a manipulative field experiment. Exclusion of mammals plus removal of fruit pulp had the greatest effect on survival, while the combined effects of dispersal failure (under parent, high density, whole fruit) and inclusion of mammals decreased the number of live seedlings present at the final count by 75-92%. Overall, most native plants were receiving adequate dispersal and there was little evidence for strong risks to plant regeneration from dispersal failure, despite the reduced bird densities and ongoing negative effects of introduced mammals in New Zealand.

Master of Science / Department of Agronomy / Anita Dille / A better understanding of kochia (Kochia scoparia) seed characteristics is necessary for long term management of this increasingly troublesome weed. The objectives were to evaluate maternal environmental factors influencing kochia seed produced in the field and to document variability in dormancy and seed viability produced within a single kochia plant grown in the greenhouse or field. Field experiments were conducted in 2012 and 2013 at the Kansas State Agricultural Research Center in Hays. Two different kochia biotypes from Hays were planted with and without five canopy types, namely corn, soybean, grain sorghum, wheat stubble, and kochia plants. A greenhouse experiment with two generations (F1 and F2) of self-pollination was conducted with the same kochia biotypes. Date of initial flowering and final plant heights were recorded. Plants were harvested when seed was mature and divided into three equal parts (top, middle, and bottom). Seeds were cold treated or not, and approximately 50 seeds were placed in petri dishes with water for germination counts taken over six weeks. Viability of remaining seeds were then tested. For field-grown kochia, plants were taller in corn, sorghum and weedy canopies compared to the absence of a canopy. Seed germination from field grown kochia ranged between 77 and 100% for both treatments. There was reduced germination in the presence of a weedy canopy for both treatments and biotypes (77 to 82%) compared to the absence (93 to 99%), with an increase in hard viable seed in the presence of weedy canopy (5 to 14%). In the greenhouse, the F2 generation produced more immediately germinable seed compared to the F1 generation which had more seed with delayed germinability. Seed from bottom third of F1 and F2 plants had greater total germination (73 and 70%, respectively) compared to the middle (61 and 65%) and top (50 and 59%) thirds of the plant. There was a maternal environmental effect on kochia seed characteristics with implications on generating persistent seed for the future seedbank.

The release of the seed eating beetle Sulcobruchus subsuturalis for biological control of Caesalpinia decapetala in South Africa has been ongoing since 2000. This is the first post release evaluation of the efficacy of the agent against the weed. The study assessed the phenology of C. decapetala and S. subsuturalis at two sites and included determining the establishment of the beetle on the target weed at 25 study sites. In addition, the effects of S. subsuturalis on seed densities as well as seed germination and seedling recruitment were examined. Furthermore predation by native ants and attacks by native parasitoids were also examined at two release sites. Mature filled pods were available on the tree from September (spring) to March (summer) when the beetle is expected to be reproductively active. The majority of beetle releases by Working for water took place in summer. However the proportion of beetle infested seeds, which were only recovered inside pods in the tree canopy at study sites, was low (0 to 15.5%). Consequently high seed densities and seedling recruitment were observed in the field. In the laboratory, S. subsuturalis did not lay eggs on buried seeds, however seed infestation levels were generally high. Only 8.3% of the seeds containing adults germinated and 6.3% emerged into seedlings. Of the seeds containing larvae, only 14.6% germinated and 2.1% emerged into seedlings. Thus far, S. subsuturalis has failed to maintain high populations on the target weed, possibly due to egg predation by native ants (Crematogaster species, Pheidole megacephala, Messor natalensis and Tetramorium avium) and attacks by native parasitoids. Egg predation reached 100% within 10 days. Egg parasitism by unknown parasitoids ranged between 80 and 93.1% in Limpopo. The parasitic wasp Dinarmus altifrons was recovered once developing inside a C. decapetala seed infested with S. subsuturalis. Further investigations regarding attacks by indigenous parasitoids on S. subsuturalis are required to determine the extent of this problem. Meanwhile releases of S. subsuturalis against C. decapetala should continue. However release efforts need to be improved by (a) using inundative rather than inoculative releases (b) Releasing every year between September and March (summer) and (c) involving land owners, farmers and nature reserve authorities in release activities. Ultimately an additional agent should be sought for release against C. decapetala as the weed may not be the preferred host for S. subsuturalis.

A pesquisa teve como objetivo estudar procedimentos para a condução dos testes de deterioração controlada, envelhecimento acelerado, condutividade elétrica e lixiviação de potássio, procurando-se verificar sua eficiência para identificação de diferentes níveis de vigor de lotes de sementes de melão (Cucumis melo L.). Para tanto, o estudo foi conduzido em duas etapas, utilizando-se cinco lotes de sementes dos híbridos AF-646 e AF-682. Na primeira foram realizados os testes de germinação, primeira contagem de germinação, Método Agroflora, emergência de plântulas em casa de vegetação e estudos específicos para os testes de deterioração controlada (graus de umidade de 18%, 21% e 24%, a 45ºC, durante 24 e 48 horas), de envelhecimento acelerado, com e sem solução salina (períodos 48, 72 e 96 horas, a 38ºC ou 41ºC), de condutividade elétrica (temperaturas de 20ºC, 25ºC e 30ºC, volumes de 50 e 75mL de água, 25 e 50 sementes e períodos de 1, 2, 4, 8, 12, 16, 20 e 24 horas) e de lixiviação de potássio (25 e 50 sementes, 50 e 75mL de água, a 25ºC e 30ºC, durante 30, 60, e 90 minutos, 2h, 2h e 30 minutos, 3, 4 e 5 horas). Os procedimentos considerados mais promissores para cada teste, nesta primeira fase, foram comparados na segunda etapa, que também incluiu os testes de germinação, primeira contagem de germinação, Método Agroflora e emergência de plântulas em casa de vegetação. Diante dos resultados obtidos, concluiu-se que os testes de deterioração controlada (24%/45ºC/24h) e de envelhecimento acelerado (procedimento tradicional e com solução salina), utilizando a combinação 41ºC/72h, apresentam sensibilidade suficiente para avaliação do potencial fisiológico de sementes de melão. O teste de condutividade elétrica não constitui em opção eficiente para avaliação do vigor das sementes, enquanto o teste de lixiviação de potássio necessita de estudos adicionais para adequar sua metodologia e viabilizar a sua utilização para sementes de melão, considerando-se, inclusive, os prováveis efeitos do genótipo. / This research was conducted to study and select procedures for the controlled deterioration, accelerate aging, electrical conductivity and potassium lixiviation tests, to verify their sensitivity to identify different vigor levels of melon (Cucumis melo L.) seed lots. Five seed lots each from the hybrids AF-646 and AF-682 were used. In the first experimental stage, the following tests were performed: germination, germination first count, Agroflora Method and seedling emergence. Specific studies were also conducted to the following tests: controlled deterioration (seed moisture content of 18%, 21% and 24%, at 45ºC, for 24 and 48 hours), traditional accelerated aging, saturated salt accelerated aging (for 48, 72 and 96 hours, at 38 o C or 41 o C), electrical conductivity (25 or 50 seeds imbibed in 50mL or 75mL water, 20 o C, 25 o C and 30 o C, for 1, 2, 4, 8, 12, 16 and 20 hours) and potassium leachate (25 or 50 seeds, imbibed in 50mL and 75mL, at 25 o C and 30 o C, for 30, 60, 90, 120, 150, 180, 240 and 300 minutes). The procedures considered the most promising for each test in the first stage were compared, in the second stage. The later stage also included germination, germination first count, Agroflora Method and seedling emergence tests. From the results, it was concluded that controlled deterioration (24%/45 o C/24h) and accelerate aging (traditional procedure and salt saturated) tests, using the 41 o C/72h combination, showed to be sufficiently sensitive for the evaluation of the physiological potential of melon seeds. The electrical conductivity test does not constitute an efficient option for the vigor evaluation, while the potassium lixiviation test needs further studies in order to adjust its methodology and enable its use for melon seeds, also considering the probable genotype effects.

O presente trabalho foi realizado visando estabelecer metodologia para o teste de germinação e verificar a possibilidade de uso do teste de raios-X para avaliar a qualidade de sementes de aroeira-branca. Foram utilizados quatro lotes de sementes colhidas em áreas da região sul de Minas Gerais, no ano de 2001. As condições de execução do teste de germinação foram determinadas com base nas percentagem e velocidade de germinação das sementes sob nove faixas de temperatura em um gradiente linear entre 15 e 35 °C e sobre os substratos papel mata-borrão, areia e vermiculita. Para o teste de raios-X, as sementes foram radiografadas e classificadas em função do estádio de desenvolvimento e da morfologia, normal e anormal, dos embriões; após o teste de germinação, procedeu-se a comparação da anatomia das sementes com as respectivas plântulas/sementes resultantes. Os resultados permitiram concluir que: (1) o teste de germinação deve ser conduzido a 27 °C, sobre substrato vermiculita e as contagens efetuadas aos 20 e 45 dias após sua instalação; (2) o teste de raios-X é eficiente na detecção de danos e anormalidades nos embriões prejudiciais à germinação. / The present work was carried out with the objective to establish a methodology for the germination test and to verify the possibility to use the X-rays in the evaluation of 'aroeira-branca' seed quality. Four seed lots collected in different places in the south region of the State of Minas Gerais in 2001 were used. The conditions for performing the germination test were determinated basing on the percentage and on the rate of seed germination under nine ranges of temperature in a linear gradient between 15 and 35°C and on substrates of blotters, sand and vermiculite. For the X-ray test, radiography of seeds were made as well as classification in relation to stage of development and morphology, normal and abnormal, of embryo; the germination test was run aiming to detect possible relationship between seedlings/seeds and the respective anatomy as revealed by radiographic pictures. It was concluded that the germination test for 'aroeira-branca' seeds may be run at 27 °C on vermiculite substrate; records have to be made on twenty and forty-five days after the begining of the test. The X-ray test was seen to be able to detect successfully damages and abnormalities in embryos of 'aroeira-branca' seeds.