Tartary buckwheat Fagopyrum tataricum (L.) Gaertn. is second cultivated species from genus buckwheat. The aim of this work was to evaluate the influence of place of growing on buckwheat production and to describe relationships among individual plant parts of tartary buckwheat. In this work weight of thousand of tartary buckwheat achenes, their total production per a plant and per area, plant number per area, plant high, number of branches, inflorescences and leaves per a plant in the fertilized, hoed and control variant was evaluated. Mean weight of roots, inflorescences, achenes, whole plant were also determined. Correlations were statistically evaluated between selected parameters. The biological yield of tartary buckwheat reached 16 t/ha dry matter and the real yield of achenes 2,9 t/ha. We can recommend application nitrogen fertilization (50 t/ha) despite statistically non significant influence of this factor.

Darbo apimtis 45 puslapiai, tame tarpe 31 paveikslas. Literatūros sąraše 51 šaltinis. Darbo pradžia 2009 09 01, pabaiga 2011 05 10. Tikslas. Ištirti grikių grūdų sklaidą nuožulniajame oro sraute. Literatūros apžvalgoje atlikta sėklų rūšiavimo būdų mokslinių tyrimų apžvalga. Atlikta grūdų valomųjų analizė bei teorinių tyrimų apžvalga. Laboratoriniais tyrimais nustatytos grikių grūdų aerodinaminės savybės ir drėgnis. Eksperimentiniais tyrimais nustatyta grikių grūdų sklaida nuožulniajame oro sraute, keičiant oro srauto greitį, kampą bei grikių grūdų srautą. Tyrimų rezultatais pagrįsta, kad grikių grūdus rūšiuojant nuožulniajame oro sraute, rekomenduojamas oro srauto greitis 10 m/s, oro srauto kampas 3 laipsniai ir grikių grūdų srautas 0,9 kg(m/s). Nustatant grikių grūdų rūšiavimo parametrus būtina atsižvelgti į dėžutėse subirusių 1000 grūdų masę. Tinkamai parinkus nuožulniojo oro srauto parametrus grikių grūdus galima rūšiuoti oro srautu. / This work consists of 45 pages, including 31 figures. There are 51 entries in the references. This work was started on the 1 st of September 2009 and it was finished on the 10th of May 2011. The object of the work. To investigate the dissemination of buckwheat grain at the bevelled air flow. The analysis studies of seed sorting techniques is made in the literature review. The research work review of grain cleaner and theoretical studies is also done. The critical speed and humidity of buckwheat grain is established by laboratory studies. Experimental studies have shown the buckwheat grain dissemination at the bevelled air flow, by changing the supply of buckwheat flow, air flow speed and angle. It was determined, that recommended buckwheat sorting at the bevelled air flow is the most effective at 10 m/s air flow rate of 0,9 kg(m/s) shall be filed in buckwheat grain flow and air flow 3 angle. In determining the screening parameters of buckwheat sorting, must be taken into account 1000 grain weight. Properly selected the parameters of beveled air flow, buckwheat can be sorting by the air flow.

abstract: Grassland habitat restoration activities are occurring within the semi-arid grasslands of the Agua Fria National Monument located 65 km north of Phoenix, AZ. The goal of these restoration activities is to reduce woody species encroachment, remove lignified plant materials and recycle nutrients within the ecosystem thus improving range conditions for both wildlife species and livestock. Broadcast burning, juniper thinning and slash pile burns are the principle tools used to accomplish resource objectives. Line cover, belt transect, densities, heights and biomass of vegetation data were collected to determine the response of the vegetative community to habitat restoration activities. Principal Component Analysis (PCA) was used to reduce data analysis to the more influential factors. Regression analysis was conducted for statistically significant response variables. Quadratic regression analysis found low predictive values. In broadcast burn treatment units, all important factors as identified by PCA had low predictive factors but significantly differed (R2 <0.01, p<0.05) between unburned and the years post treatment. Regression analysis found significant, albeit weak, relationships between time since treatment and independent variables. In pile burn treatment units, data reduction by PCA was not possible in a biologically meaningful way due to the high variability within treatment units. This suggests the effect of juniper encroachment on grassland vegetation persists long after junipers have been cut and burned. This study concluded that broadcast burning of the central Arizona grasslands does significantly alter many components of the vegetative community. Fuels treatments generally initially reduced both perennial woody species and grasses in number and height for two year post fire. However, palatable shrubs, in particular shrubby buckwheat, were not significantly different in broadcast burn treatment areas. The vegetative community characteristics of juniper encroached woodlands of central Arizona are unaffected by the removal and burning of junipers aside from the removal of hiding cover for predators for multiple years. It is recommended that habitat restoration activities continue provided the needs of wildlife are considered, especially pronghorn, with the incorporation of state and transition models specific to each of the respective ecological site descriptions and with the consideration of the effects of fire to pronghorn fawning habitat. / Dissertation/Thesis / M.S. Applied Biological Sciences 2014

En s’appuyant sur les démarches récentes en palynologie appliquée à l’histoire rurale, la thèse pose trois objectifs : (1) questionner la chronologie des essors et déprises des paysages agropastoraux du nord de la Haute-Bretagne entre le XIe et le XVIe siècle, (2) réfléchir à l’originalité de ce secteur par rapport aux territoires environnants, (3) analyser le poids descontextes économiques et sociaux sur l’aménagement des paysages. Les dynamiques des paysages agropastoraux mettent en évidence une chronologie classique pour le début de la période. Un essor de la croissance touche l’ensemble du secteur aux XIe-XIIe s. Cet essor amène progressivement à une situation de blocage à partir du XIIIe s. Ces dynamiques se transcrivent dans les pratiques. On observe un glissement de pratiques de cultures temporaires et de prairies gérées extensivementà une intensification progressive des activités agricoles. L’originalité concerne les crises des XIVe-XVe s. qui ne sont perçues qu’à proximité de la frontière normande. Le secteur de Rennes est concerné par un dynamisme agricole qui prend la forme d’une intensification de la céréaliculture, avec la mise en place d’un système de rotation intégrant la culture du sarrasin. Ce changement dans les pratiques agropastorales est peut-être une réponse au blocage de la croissance. Il est surtout permis par le dynamisme économique qui touche le duché de Bretagne aux XIVe-XVe s. La croissance n’atteint la frontière normande qu’à compter de la seconde moitié du XVe s. Ce décalage s’observe également dans la production de chanvre textile qui a marqué les paysages des campagnes de Haute-Bretagne. Les données polliniques interrogent ainsi l’origine des zones de production de toiles connues à l’époque moderne. / Based on recent approaches in pollen analysis applied to rural history, this PhD dissertation has three objectives: (1) to question the chronology of agrarian expansion and regression in northern Upper Brittany between 11th and 16th century; (2) to ponder the originality of this area in relation to the surrounding areas; (3) to analyze the weight of economic and socialcontexts on the construction of landscapes. The changes in agro-pastoral landscapes reveal a rather classical chronology for the beginning of the period. The agricultural expansion affects the whole area in the 11th and 12th centuries. This expansion gradually leads to a stalling of growth in the 13th century. These changes affected practices. Thus we observe a shift from practices of temporary crops and extensively-managed grasslands towards a gradual intensification of agricultural activities. The originality concerns the late medieval agrarian crisis which is only detected close to the Norman border. The area of Rennes, on the other hand, is affected by an agricultural expansion which takes the form of an intensification of cereal farming, with the introduction of a new system of crop rotation integrating the cultivation of buckwheat. This change in agro-pastoral practices may be an answer to the stalling of growth. This change is mainly allowed by the economic dynamism that affects the duchy of Brittany in the 14th and 15th centuries. Growth doesn’t reach the Norman border until the second half of the 15th century. This time-lag can also be seen in the production of bastfibres of hemp which transformed the landscapes of rural Upper Brittany. Thus the palynological analysis questions the origin of the areas of production of canvases known in early modern times.

No description available.

It is not known whether seed inoculated soybean intercropping can increase the number of nodules, nitrogen uptake and yield of the subsequent main crop, soybean. For this reason, the soybean intercropping approach, sole or mixed cropping with buckwheat, was adopted to examine the influence of inoculation and intercropping of soybean and buckwheat on the subsequent main crop, soybean. Field trials were conducted from 2016 to 2019 in Germany and Poland. For this purpose, soils on which soybeans had not been grown in the past were selected as experimental plots and laid out in a split-plot design. It was surprising that even without inoculation a nodule growth could be documented. However, intercrop inoculation resulted in an average of 12 times more nodules per plant at four out of five sites. In addition, a 43% higher number of nodules was found on the lateral roots of the main soybean crop when intercropping with inoculated soybean occurred. The influence of the intercrop on the main crop soybean also depended on their growth in late summer and autumn. Further, there was a medium relationship (R = 0.7) between the number of nodules in the intercrop soybean and the nitrogen content of the soybean grain in the main crop. In terms of soybean grain yield, a single inoculation of the intermediate soybean crop contributed an average of 5% higher yield and inoculation of both the intercrops, and the main crop improved yield by 15%.

<p>U okviru disertacije ispitani su i upoređeni pokazatelji kvaliteta integralnog p&scaron;eničnog i integralnog heljdinog bra&scaron;na dobijenog mlevenjem netretiranih (netretirano integralno heljdino bra&scaron;no) i autoklaviranih zrna heljde (autoklavirano integralno heljdino bra&scaron;no). Nakon ispitivanja nutritivnih i funkcionalnih svojstava pomenutih bra&scaron;na, kreirane su i proizvedene integralne taljatele sa različitim sadržajem integralnog heljdinog bra&scaron;na (10&ndash;30%).<br />Pokazatelji senzorskog, nutritivnog i funkcionalnog kvaliteta proizvedenih taljatela sa integralnim heljdinim bra&scaron;nima ispitani su u poređenju sa kontrolnim uzorkom taljatela od integralnog p&scaron;eničnog bra&scaron;na.<br />U ispitivanim uzorcima bra&scaron;na i taljatela određeni su osnovni hemijski sastav, sadržaj mineralnih materija, sadržaj ukupnih rastvorljivih polifenola, utvrđen je kvalitativni i kvantitativni sastav polifenolnih jedinjenja, ispitana je antiradikalska aktivnost na DPPH˙ i određen je sadržaj fitinske kiseline i 5-hidroksimetilfurfural.<br />Pored analize nutritivnih i funkcionalnih svojstava, na taljatelama su sprovedena ispitivanja fizičkih osobina (dimenzije) i svojstva taljatela pri kuvanju. Instrumentalno su izmereni boja i teksturna svojstva nekuvanih i kuvanih taljatela. Senzorska ocena taljatela sprovedena je uz primenu panela utreniranih ocenjivača, metodom bodovanja i panela potro&scaron;ača, testom dopadljivosti.<br />Dobijeni rezultati ukazuju da se supstitucijom dela integralnog p&scaron;eničnog bra&scaron;na integralnim heljdinim bra&scaron;nom (autoklaviranim ili netretiranim) postiže unapređenje nutritivnog i funkcionalnog profila uzoraka obogaćenih taljatela, uz manje ili vi&scaron;e izraženo naru&scaron;avanje senzorskog profila, u zavisnosti od stepena supstitucije i vrste integralnog heljdinog bra&scaron;na.</p> / <p>This study investigated quality parameters of wholegrain wheat flour and wholegrain buckwheat flour from non-treated buckwheat grains (non-treated wholegrain buckwheat flour) and autoclaved buckwheat grains (autoclaved wholegrain buckwheat flour). After investigation of nutritional and functional properties of aforementioned flours, new wholegrain tagliatelle formulations, with different wholegrain buckwheat flour content (10&ndash;30%) have been developed.<br />Sensory, nutritional and functional quality parameters of buckwheat containing tagliatelle samples were analysed and compared with control tagliatelle sample from wholegrain wheat flour.<br />Proximate composition, content of minerals, content of total polyphenols and quantitative and qualitative composition of polyphenols were investigated in both, flour samples and produced uncooked and cooked tagliatelle samples. Antiradical activity on DPPH radicals, and content of less favourable compounds, phytic acid and HMF, have been tested, as well.<br />Tagliatelle physical properties, dimensions, cooking properties, colour and textural properties were determined by instrumental and sensory methods. Tagliatelle acceptability was evaluated by the consumers. The obtained results indicate that wholegrain buckwheat flour (autoclaved or non-treated) incorporation into tagliatelle formulation led to an improvement of nutritional and functional profiles of tagliatelle samples, followed by greater or lesser deterioaration of sensory profile, depending on substitution level and type of wholegrain buckwheat flour.</p>

Trichogramma carverae Oatman and Pinto is mass-released for biological control of the leafroller pest, light brown apple moth, Epiphyas postvittana (Walker) in Australian vineyards. Parasitoid performance can, however, be constrained by a lack of suitable adult food and no information is available on the effect of nectar on the parasitism and longevity of T. carverae. To address this, the effect of alyssum, Lobularia maritima (L.) flowers on E. postvittana parasitism was studied in a vineyard experiment with and without releases of T. carverae. Egg parasitoid activity was assessed with E. postvittana egg �sentinel cards� and no parasitism was recorded in plots without T. carverae releases. Where T. carverae were released, there was no significant enhancement of parasitism by the presence of L. maritima flowers. Three hypotheses were subsequently tested to account for the lack of an effect: (i) T. carverae does not benefit from L. maritima nectar, (ii) T. carverae was feeding on nectar from other flowering plants (weeds) present in the vineyard, (iii) T. carverae was feeding on sugars from ripe grapes. A growth-cabinet experiment using potted L. maritima plants with and without flowers did not support hypothesis one. No parasitism was recorded after day two for T. carverae caged without flowers whilst parasitism occured until day eight in the presence of flowers. A laboratory experiment with common vineyard weeds (Trifolium repens, Hypochoeris radicata, Echium plantagineum) as well as L. maritima did not support hypothesis one but gave partial support to hypothesis two. Survival of T. carverae was enhanced to a small but statistically significant extent in vials with intact flowers of L. maritima, white clover (T. repens) and catsear (H. radicata) but not in vials with flowering shoots of these species from which flowers and flowering buds had been removed. Paterson�s curse (E. plantagineum) flowers had no effect on T. carverae survival. In a laboratory study, punctured grapes significantly enhanced T. carverae survival compared with a treatment without grapes, supporting hypothesis three. Trichogramma carverae performance in the field experiment was probably also constrained by relatively cool and wet weather. Further work on the enhancement of T. carverae efficacy by L. maritima and other carbohydrate sources is warranted. Greenhouse and field experiments were conducted to investigate whether T. carverae benefit from different groundcover plant species. Ten T. carverae adults (<24h after eclosion) were caged with different groundcover species and a control with no plant materials. Epiphyas postvittana egg sentinel cards were used to measure parasitism and longevity was recorded visually. Survival and realised parasitism of T. carverae was significantly higher in L. maritima than in Brassica juncea, Coriandrum sativum, shoots of these species from which flowers had been removed and nil control treatments. A similar experiment with Fagopyrum esculentum (with- and without-flowers) and a control treatment showed that survival was significantly higher in intact F. esculentum than in without-flower and control treatments. There was no significant treatment effect on parasitism in the early stages of that experiment, though parasitism was recorded in the presence of F. esculentum flowers for 12 days, compared with 6 days in other treatments. Higher parasitism was observed in intact Borago officinalis than in the flowerless shoot, water only and no plant material control treatments in a third experiment. There was no significant treatment effect on parasitism. Fitted exponential curves for survival data differed significantly in curvature in the first, second and third experiments but the slope was a non-significant parameter in the second and third experiments. In a second series of laboratory experiments, one male and one female T. carverae were caged with groundcover species to investigate male and female longevity and daily fecundity. Both male and female longevity in F. esculentum and L. maritima treatments were significantly higher than on shoots of these species from which flowers had been removed, and than in the control treatments. Daily fecundity was significantly greater in the intact L. maritima treatment than in all other treatments. Fitted exponential curves for daily fecundity differed significantly in position and slope but not in curvature. There was no significant treatment effect on longevity or parasitism when a male and female were caged with intact B. juncea, B. officinalis or without-flower of these species, nor in the treatment with no plant materials. No parasitism was observed in a survey of naturally occurring egg parasitoids on two sites close to Orange and Canowindra in New South Wales, illustrating the importance of mass releases of T. carverae in biological control of E. postvittana. In an experiment on the Canowindra site, parasitism was significantly higher on day one and day two after T. carverae release when with-flower treatments were compared with without-flower treatments. Parasitism was significantly higher in the F. esculentum treatment than in C. sativum, L. maritima, vegetation without-flowers and control treatments on these dates. On day five, parasitism was higher in C. sativum than in all other treatments. There was no significant increase in parasitism in a second experiment conducted on the Orange site. Coriandrum sativum, F. esculentum and L. maritima appear to be suitable adult food sources for T. carverae and offer some scope for habitat manipulation in vineyards The adults of many parasitoid species require nectar for optimal fitness but very little is known about flower recognition. Flight cage experiments showed that the adults of T. carverae benefited from L. maritima bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered cultivars, despite all cultivars producing nectar. Survival and realised parasitism on non-white flowers were no greater than when the parasitoids were caged on L. maritima shoots from which flowers had been removed. The possibility that differences between L. maritima cultivars were due to factors other than flower colour, such as nectar quality, was excluded by dyeing white L. maritima flowers by placing the roots of the plants in 5% food dye (blue or pink) solution. Survival of T. carverae was lower on dyed L. maritima flowers than on undyed white flowers. Mixing the same dyes with honey in a third experiment conducted in the dark showed that the low level of feeding on dyed flowers was unlikely to be the result of olfactory or gustatory cues. Flower colour appears, therefore, to be a critical factor in the choice of plants used to enhance biological control, and is likely to also be a factor in the role parasitoids play in structuring invertebrate communities. Provision of nectar producing plants to increase the effectiveness of biological control is one aspect of habitat manipulation, but care needs to be taken to avoid the use of plant species that may benefit pest species. Greenhouse experiments were conducted to investigate whether the adult E. postvittana and larvae benefit from nectar producing groundcover species. Newly emerged E. postvittana adults were caged with different groundcover species and a honey-based artificial adult diet. The longevity of male and female E. postvittana when caged with shoots of borage (B. officinalis) and buckwheat (F. esculentum) bearing flowers was as long as when fed a honey-based artificial diet. This effect was not evident when caged with shoots of these plants from which flowers had been removed. Longevity was significantly lower than in the artificial diet treatment when caged with coriander (C. sativum) or alyssum (L. maritima) irrespective of whether flowers were present or not. There was no significant treatment effect on the lifetime fecundity of E. postvittana. A second experiment with mustard (B. juncea) (with- and without-flowers), water only and honey-based artificial adult diet showed no significant treatment effects on the longevity of male and female E. postvittana or on the lifetime fecundity of E. postvittana. The anomalous lack of a difference between the water and honey-based diet treatments precludes making conclusions on the value of B. juncea for E. postvittana. Two greenhouse experiments were conducted to evaluate the effects of groundcover species on the larval development of E. postvittana. In the first experiment, larval mortality was significantly higher in C. sativum, and L. maritima than in B. juncea, B. officinalis and white clover (T. repens) a known host of E. postvittana. Coriandrum sativum and L. maritima extended the larval period. In B. juncea and B. officinalis, mortality did not differ from that in T. repens. In F. esculentum, larval mortality was significantly higher than in T. repens. A short larval period was observed on B. juncea, B. officinalis and F. esculentum. Fitted exponential curves for larval mortality differed significantly in curvature between plant treatments. Similarly, successful pupation was significantly lower in C. sativum, F. esculentum and L. maritima than in T. repens. The percentage of successful pupation in B. juncea and B. officinalis did not differ from F. esculentum and T. repens. Fitted exponential curves for pupation differed significantly in curvature. A similar trend was observed in a second experiment with potted plants. The overall results suggest that C. sativum and L. maritima denied benefit to E. postvittana adults and larvae, so could be planted as vineyard groundcover with minimal risk of exacerbating this pest. Overall results suggest that T. carverae require nutrients to reach their full reproductive potential and flowers provide such nutrients. Lobularia maritima and C. sativum may be considered �selective food plants� for T. carverae whereas F. esculentum appears to be a �non-selective food plant�; both T. carverae and E. postvittana benefited from it. Fruits such as grapes can be used as food resources in habitat manipulation and this merits further research. This result also suggests that within species flower colour is an important factor for flower selection in habitat manipulation.

Trichogramma carverae Oatman and Pinto is mass-released for biological control of the leafroller pest, light brown apple moth, Epiphyas postvittana (Walker) in Australian vineyards. Parasitoid performance can, however, be constrained by a lack of suitable adult food and no information is available on the effect of nectar on the parasitism and longevity of T. carverae. To address this, the effect of alyssum, Lobularia maritima (L.) flowers on E. postvittana parasitism was studied in a vineyard experiment with and without releases of T. carverae. Egg parasitoid activity was assessed with E. postvittana egg �sentinel cards� and no parasitism was recorded in plots without T. carverae releases. Where T. carverae were released, there was no significant enhancement of parasitism by the presence of L. maritima flowers. Three hypotheses were subsequently tested to account for the lack of an effect: (i) T. carverae does not benefit from L. maritima nectar, (ii) T. carverae was feeding on nectar from other flowering plants (weeds) present in the vineyard, (iii) T. carverae was feeding on sugars from ripe grapes. A growth-cabinet experiment using potted L. maritima plants with and without flowers did not support hypothesis one. No parasitism was recorded after day two for T. carverae caged without flowers whilst parasitism occured until day eight in the presence of flowers. A laboratory experiment with common vineyard weeds (Trifolium repens, Hypochoeris radicata, Echium plantagineum) as well as L. maritima did not support hypothesis one but gave partial support to hypothesis two. Survival of T. carverae was enhanced to a small but statistically significant extent in vials with intact flowers of L. maritima, white clover (T. repens) and catsear (H. radicata) but not in vials with flowering shoots of these species from which flowers and flowering buds had been removed. Paterson�s curse (E. plantagineum) flowers had no effect on T. carverae survival. In a laboratory study, punctured grapes significantly enhanced T. carverae survival compared with a treatment without grapes, supporting hypothesis three. Trichogramma carverae performance in the field experiment was probably also constrained by relatively cool and wet weather. Further work on the enhancement of T. carverae efficacy by L. maritima and other carbohydrate sources is warranted. Greenhouse and field experiments were conducted to investigate whether T. carverae benefit from different groundcover plant species. Ten T. carverae adults (<24h after eclosion) were caged with different groundcover species and a control with no plant materials. Epiphyas postvittana egg sentinel cards were used to measure parasitism and longevity was recorded visually. Survival and realised parasitism of T. carverae was significantly higher in L. maritima than in Brassica juncea, Coriandrum sativum, shoots of these species from which flowers had been removed and nil control treatments. A similar experiment with Fagopyrum esculentum (with- and without-flowers) and a control treatment showed that survival was significantly higher in intact F. esculentum than in without-flower and control treatments. There was no significant treatment effect on parasitism in the early stages of that experiment, though parasitism was recorded in the presence of F. esculentum flowers for 12 days, compared with 6 days in other treatments. Higher parasitism was observed in intact Borago officinalis than in the flowerless shoot, water only and no plant material control treatments in a third experiment. There was no significant treatment effect on parasitism. Fitted exponential curves for survival data differed significantly in curvature in the first, second and third experiments but the slope was a non-significant parameter in the second and third experiments. In a second series of laboratory experiments, one male and one female T. carverae were caged with groundcover species to investigate male and female longevity and daily fecundity. Both male and female longevity in F. esculentum and L. maritima treatments were significantly higher than on shoots of these species from which flowers had been removed, and than in the control treatments. Daily fecundity was significantly greater in the intact L. maritima treatment than in all other treatments. Fitted exponential curves for daily fecundity differed significantly in position and slope but not in curvature. There was no significant treatment effect on longevity or parasitism when a male and female were caged with intact B. juncea, B. officinalis or without-flower of these species, nor in the treatment with no plant materials. No parasitism was observed in a survey of naturally occurring egg parasitoids on two sites close to Orange and Canowindra in New South Wales, illustrating the importance of mass releases of T. carverae in biological control of E. postvittana. In an experiment on the Canowindra site, parasitism was significantly higher on day one and day two after T. carverae release when with-flower treatments were compared with without-flower treatments. Parasitism was significantly higher in the F. esculentum treatment than in C. sativum, L. maritima, vegetation without-flowers and control treatments on these dates. On day five, parasitism was higher in C. sativum than in all other treatments. There was no significant increase in parasitism in a second experiment conducted on the Orange site. Coriandrum sativum, F. esculentum and L. maritima appear to be suitable adult food sources for T. carverae and offer some scope for habitat manipulation in vineyards The adults of many parasitoid species require nectar for optimal fitness but very little is known about flower recognition. Flight cage experiments showed that the adults of T. carverae benefited from L. maritima bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered cultivars, despite all cultivars producing nectar. Survival and realised parasitism on non-white flowers were no greater than when the parasitoids were caged on L. maritima shoots from which flowers had been removed. The possibility that differences between L. maritima cultivars were due to factors other than flower colour, such as nectar quality, was excluded by dyeing white L. maritima flowers by placing the roots of the plants in 5% food dye (blue or pink) solution. Survival of T. carverae was lower on dyed L. maritima flowers than on undyed white flowers. Mixing the same dyes with honey in a third experiment conducted in the dark showed that the low level of feeding on dyed flowers was unlikely to be the result of olfactory or gustatory cues. Flower colour appears, therefore, to be a critical factor in the choice of plants used to enhance biological control, and is likely to also be a factor in the role parasitoids play in structuring invertebrate communities. Provision of nectar producing plants to increase the effectiveness of biological control is one aspect of habitat manipulation, but care needs to be taken to avoid the use of plant species that may benefit pest species. Greenhouse experiments were conducted to investigate whether the adult E. postvittana and larvae benefit from nectar producing groundcover species. Newly emerged E. postvittana adults were caged with different groundcover species and a honey-based artificial adult diet. The longevity of male and female E. postvittana when caged with shoots of borage (B. officinalis) and buckwheat (F. esculentum) bearing flowers was as long as when fed a honey-based artificial diet. This effect was not evident when caged with shoots of these plants from which flowers had been removed. Longevity was significantly lower than in the artificial diet treatment when caged with coriander (C. sativum) or alyssum (L. maritima) irrespective of whether flowers were present or not. There was no significant treatment effect on the lifetime fecundity of E. postvittana. A second experiment with mustard (B. juncea) (with- and without-flowers), water only and honey-based artificial adult diet showed no significant treatment effects on the longevity of male and female E. postvittana or on the lifetime fecundity of E. postvittana. The anomalous lack of a difference between the water and honey-based diet treatments precludes making conclusions on the value of B. juncea for E. postvittana. Two greenhouse experiments were conducted to evaluate the effects of groundcover species on the larval development of E. postvittana. In the first experiment, larval mortality was significantly higher in C. sativum, and L. maritima than in B. juncea, B. officinalis and white clover (T. repens) a known host of E. postvittana. Coriandrum sativum and L. maritima extended the larval period. In B. juncea and B. officinalis, mortality did not differ from that in T. repens. In F. esculentum, larval mortality was significantly higher than in T. repens. A short larval period was observed on B. juncea, B. officinalis and F. esculentum. Fitted exponential curves for larval mortality differed significantly in curvature between plant treatments. Similarly, successful pupation was significantly lower in C. sativum, F. esculentum and L. maritima than in T. repens. The percentage of successful pupation in B. juncea and B. officinalis did not differ from F. esculentum and T. repens. Fitted exponential curves for pupation differed significantly in curvature. A similar trend was observed in a second experiment with potted plants. The overall results suggest that C. sativum and L. maritima denied benefit to E. postvittana adults and larvae, so could be planted as vineyard groundcover with minimal risk of exacerbating this pest. Overall results suggest that T. carverae require nutrients to reach their full reproductive potential and flowers provide such nutrients. Lobularia maritima and C. sativum may be considered �selective food plants� for T. carverae whereas F. esculentum appears to be a �non-selective food plant�; both T. carverae and E. postvittana benefited from it. Fruits such as grapes can be used as food resources in habitat manipulation and this merits further research. This result also suggests that within species flower colour is an important factor for flower selection in habitat manipulation.

This thesis analyses buckwheat as a cover crop in Florida. The study was designed to demonstrate: soil enrichment with nutrients, mycorrhizal arbuscular fungi interactions, growth in different soil types, temperature limitations in Florida, and economic benefits for farmers. Buckwheat was planted at the FIU organic garden (Miami, FL) in early November and harvested in middle December. After incorporation of buckwheat residues, soil analyses indicated the ability of buckwheat to enrich soil with major nutrients, in particular, phosphorus. Symbiosis with arbuscular mycorrhizal fungi increased inorganic phosphorus uptake and plant growth. Regression analysis on aboveground buckwheat biomass weight and soil characteristics showed that high soil pH was the major limiting factor that affected buckwheat growth. Spatial analysis illustrated that buckwheat could be planted in South Florida throughout the year but might not be planted in North and Central Florida in winter. An economic assessment proved buckwheat to be a profitable cover crop.