To better understand how photoperiod and body size interact to affect age at maturity, PIT-tagged... more To better understand how photoperiod and body size interact to affect age at maturity, PIT-tagged 2-year-old Salvelinus alpinus (ca. 300 g, n=330) were reared in fresh water from February 3 under four treatments, either 18-h light/6-h dark (LD18:6) for 42 days then LD8:16 (long–short); LD18:6 for 42 days then simulated natural (long–ambient); constant LD18:6 (constant–long); or simulated seasonal photoperiod cycle
Single- and multiple-input transfer function (TF) models and their applications in modeling strea... more Single- and multiple-input transfer function (TF) models and their applications in modeling streamflow systems are reviewed. To account for nonlinearities in streamflows, a procedure for generating the two most important inputs, snowmelt and effective rain, using nonlinear filters is proposed. A multiple-input TF model identification procedure that uses a vector autoregressive model and the Corner method is proposed. These procedures
Journal of Environmental Engineering and Science, 2002
The effect of two different thermal units (flame and hot steam) and three types of mulch on the p... more The effect of two different thermal units (flame and hot steam) and three types of mulch on the percentage of weeds killed was studied in a series of experiments over 2 years. The factors studied were driving speed (2, 3, 4 km/h), flame treatment (first, second, third), growth stage (<6, 6-8, >8 true leaves), hot steam treatment (single, double), mulch type (none, coarse bark, sawdust, hay), and chemical application. The results suggest that a driving speed of 2 km/h kills the highest percentage of weeds, and for weed species with unprotected growth points and thin leaves, the first flame application can completely kill weeds with <6 leaves. However, a second or third flame application is required for those with 6 or more leaves. The hot steam method is effective when it is applied twice, with the second application 1 week after the first. However, there is room for improving its technology to make it cost effective for large-scale applications. Mulches after chemical herbicide application are effective for controlling weeds. However, mulching cannot be recommended with flaming because of fire hazard. The effectiveness of herbicide depends on the weed species and on whether the same herbicide was used in the preceding years. Compared to using herbicide with mulching, herbicide alone was less effective in controlling weeds and more costly in terms of cost per hectare and the environment.
We conducted two experiments on Shubenacadie River stock of Morone saxatilis fed trout pellets. E... more We conducted two experiments on Shubenacadie River stock of Morone saxatilis fed trout pellets. Experiment 1 compared juveniles of ca. 40 and 550 g initial body weight in hard freshwater (FW) for 73 days at either 20, 24 or 28 °C. Experiment 2 lasting 115 days compared 40, 300 and 800 g fish in either FW or seawater (SW, 30
HortScience: a publication of the American Society for Horticultural Science
... Tess Astatkie. Nova Scotia Agricultural College, Department of Engineering, PO Box 550, Truro... more ... Tess Astatkie. Nova Scotia Agricultural College, Department of Engineering, PO Box 550, Truro, NS, B2N 5E3, Canada. Dolores Fratesi. Lauren Farms ... samples were dried at room temperature and sent for analysis of residual phyto-available nutrients using the Lancaster soil test ...
Peppermint (Mentha X piperita L.) and spearmint (Mentha spicata L.) are major essential oil crops... more Peppermint (Mentha X piperita L.) and spearmint (Mentha spicata L.) are major essential oil crops in the US and worldwide. The objective of this controlled environment study was to evaluate the effect of three plant hormones (salicylic acid SA, methyl jasmonate MJ, and gibberelic acid GA3, each at 10, 100 and 1000 mg/L, applied as a foliar spray), on biomass yields, essential oil content and oil yields of peppermint and spearmint. Overall, the application of SA at 1000 mg/L increased biomass yields of both mints relative to the control, while the other treatments were not significantly different from the control. The essential oil content was higher in peppermint than in spearmint, and treatments had different effect on the two mint species. The application of MJ at 100 and 1000 mg/L, GA at 10 mg/L, SA at 10 and at 100 mg/L, increased the essential oil content of peppermint, while the oil content of spearmint was not affected by treatments. None of the treatments reduced essential o...
Canadian Journal of Fisheries and Aquatic Sciences, 2005
The potential for sire size to influence life history patterns from fry to sea age at maturity wa... more The potential for sire size to influence life history patterns from fry to sea age at maturity was established by rearing individually identified half-sibs of a single dam and either small (parr) or large (anadromous) sires in a common tank environment. Male sexual maturity was higher among progeny of small versus large sires at both parr (age 0+, 50% versus
Subsurface drainage discharge nitrate-N (NO3-N) losse s were evaluated under corn during a three ... more Subsurface drainage discharge nitrate-N (NO3-N) losse s were evaluated under corn during a three year period under three replicated drainage systems: i) 100 mm diameter drainage tile at 80 cm depth; ii) 50 mm diameter drainage tile at 80 cm depth and iii) 50 mm diameter drainage tile at 50 cm depth. Each drainage system had 72 m spacings between laterals. The field under investigation possessed shallow, imperfectly-to-poorly drained soils. Throughout the investigation average NO3-N concentiations in the drainage outflow were similar for all three systems ranging from 9.6-11.4 mgL-1. Total drainage discharge was significantly lower for the shallow (50 cm) system compared to the two deeper (80 cm) systems. Therefore, significant differences in total NO3-N loss between the shallow (50 cm) and deep (80 cm) systems were observed with shallow systems providing reduced NO3-N losses. Corn yields were significantly lower in the shallow (50 cm) drainage treatment in only one year. Shallow drainage may have many economical and environmental benefits and require further research to evaluate its potential under various soil types. REsUME Les pertes de nitrate-N (NO.-N) pour les dcoulements de drainage souterrains ont 6t6 6va1u6es sous les plantations de mais au cours d'une p6riode de trois ans pour trois systdmes de drainage ayant (,t€ reproduits : i) un tuyau de drainage d'un diamdtre de 100 mm d une profondeur de 80 cm; ii) un tuyau de drainage d'un diamitre de 50 mm i une profondeur de 80 cm et iii) un tuyau de drainage d'un diamdtre de 50 mm ) une profondeur de 50 cm. Chaque systdme de drainage comportait un espacement de L2 m entre les canalisations secondaires. dtudi6 possddait des sols de faible profondeur dont 1e drainage allait d'imparfait d pidtre. Tout au long de 1'6tude, 1es concentrations de NO3-N moyennes dans le d6bit de drainage 6taient semblables pour 1es trois systdmes, al1ant de 9,6 d.71,,4 mg L-1. Le d6bit de drainage total 6tait consid6rablement moins 61ev6 pour le systdme de faible profondeur (50 cm) comparativement aux deux systdmes plus profonds (80 cm), Par cons6quent, des 6carts consid6rables dans la perte de NO3-N totale entre le systdme de faible profondeur (50 cm) et les systdmes profonds (80 cm) ont 6t6 observ6s, Ie systdme de faible profondeur offrant des pertes de NO.-N rdduites. Le rendement des plantations de mais 6tait consid6rablement plus faible dans le traitement de drainage (50 cm) en l'espace d un an seulement. Le drainage i faible profondeur peut pr6senter de nombreux avantages sur les plans 6conomique et environnemental. Il demande de plus amples recherches afin d'6valuer ses possibilit6s en fonction de divers types de sol.
a b s t r a c t 'Native' spearmint (Mentha spicata L.) is one of the two spearmint species grown ... more a b s t r a c t 'Native' spearmint (Mentha spicata L.) is one of the two spearmint species grown commercially in the United States and other countries for essential oil production. The two major constituents of spearmint oil are carvone and limonene. It is not known if the essential oil yield (content) and composition of spearmint oil are affected by diurnal variation, and when it would be the best time for harvesting flowering spearmints within a 24 h period. Therefore, the objective of this study was to evaluate the effect of diurnal variation on yield and composition of spearmint 'Native' essential oil for the environmental conditions of Northern Wyoming, at elevation 1170 m above the sea level. The experiment was conducted on a 3-year old well established spearmint plantation. The harvest times were every 2 h within a
ABSTRACT The objectives of this study were to determine the effects of distillation time (DT; 15–... more ABSTRACT The objectives of this study were to determine the effects of distillation time (DT; 15–1080 min) on yield, composition, and antioxidant capacity of fennel (Foeniculum vulgare) seed essential oil (EO) as well as on the yield, composition, and properties of lipids extracted from steam-distilled fennel seeds (15–600 min). EO yield increased with increasing DT to a maximum of 1.375% at 1080 min. The principal constituent was estragole, comprising 82–91% of the overall content. Other species included limonene, fenchone, and anethole. Antioxidant capacity of the EO was essentially unaffected by DT, with capacities ranging from 11.2 to 20.6 μmol Trolox/g. The yield of lipids extracted from steam distilled fennel seeds was unaffected by DT and ranged from 21.7 to 22.8 mass%. The fatty acid composition was also unaffected by DT, and the major constituents were petroselenic (67.0–71.3%) and oleic (12.0–16.4%) acids. The concentrations of tocopherols, tocotrienols, and phytosterols were unaffected by DT whereas unsaponifiables and EO content in lipids decreased with increasing DT. Acid value, kinematic viscosity, peroxide value, and pour point increased with increasing DT, whereas density decreased. Induction period, heteroatom content, and Gardner color were unaffected by DT. As DT increased, in vitro degradability of defatted, steam-distilled fennel seeds decreased. In summary, longer DT negatively impacted feed quality of steam-distilled, defatted seed meal and lipid quality but did not significantly affect EO composition and antioxidant capacity.
Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce ... more Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce the pressure and to release the methane, the water needs to be pumped out. The resulting waste water is known as coal bed methane water (CBMW). Major concerns with the use of CBMW are its high concentrations of S, Na, dissolved Ca, Mg, SO, and bicarbonate (HCO). Irrigation water is a scarce resource in most of the western states. The objective of this study was to evaluate the effect of various amounts of CBMW on the growth, essential oil content, composition, and antioxidant activity of spearmint ( L.) and peppermint ( L.) crops that were irrigated with the water. These two crops are grown in some western states and are potential specialty crops to Wyoming farmers. The irrigation treatments were 0% CBMW (tap water only), 25% CBMW (25% CBMW plus 75% tap water), 50% CBMW (50% CBMW and 50% tap water), 75% CBMW (75% CBMW plus 25% tap water), and 100% CBMW. Analyses of the data revealed that the CBMW treatments did not affect the antioxidant capacity of spearmint or peppermint oil (242 and 377 μmol L Trolox g, respectively) or their major oil constituents (carvone or menthol). Coal bed methane water at 100% increased total phenols and total flavonoids in spearmint but not in peppermint. Coal bed methane water also affected oil content in peppermint but not in spearmint. Spearmint and peppermint could be watered with CBMW at 50% without suppression of fresh herbage yields. However, CBMW at 75 and 100% reduced fresh herbage yields of both crops and oil yields of peppermint relative to the control.
Historical development of nonlinear stochastic modeling of streamflows is discussed. Physical con... more Historical development of nonlinear stochastic modeling of streamflows is discussed. Physical considerations and graphical investigations of daily streamflows revealed that air temperature and state of basin storage are the most important sources of nonlinearity in catchments with seasonal snow accumulation. The average temperature for the preceding three days, and the flow one or two days earlier were adequate proxies for the temperature and storage conditions of a catchment. The Nested Threshold Autoregressive (NeTAR) model, which considers these sources of nonlinearity simultaneously, was applied to two years of daily flows of the Oldrnan River near Brocket in Alberta, Canada. A third year of daily data was used fbr validating the model. The final NeTAR model provided useful insights into the dynamics of this streamflow system.
To better understand how photoperiod and body size interact to affect age at maturity, PIT-tagged... more To better understand how photoperiod and body size interact to affect age at maturity, PIT-tagged 2-year-old Salvelinus alpinus (ca. 300 g, n=330) were reared in fresh water from February 3 under four treatments, either 18-h light/6-h dark (LD18:6) for 42 days then LD8:16 (long–short); LD18:6 for 42 days then simulated natural (long–ambient); constant LD18:6 (constant–long); or simulated seasonal photoperiod cycle
Single- and multiple-input transfer function (TF) models and their applications in modeling strea... more Single- and multiple-input transfer function (TF) models and their applications in modeling streamflow systems are reviewed. To account for nonlinearities in streamflows, a procedure for generating the two most important inputs, snowmelt and effective rain, using nonlinear filters is proposed. A multiple-input TF model identification procedure that uses a vector autoregressive model and the Corner method is proposed. These procedures
Journal of Environmental Engineering and Science, 2002
The effect of two different thermal units (flame and hot steam) and three types of mulch on the p... more The effect of two different thermal units (flame and hot steam) and three types of mulch on the percentage of weeds killed was studied in a series of experiments over 2 years. The factors studied were driving speed (2, 3, 4 km/h), flame treatment (first, second, third), growth stage (<6, 6-8, >8 true leaves), hot steam treatment (single, double), mulch type (none, coarse bark, sawdust, hay), and chemical application. The results suggest that a driving speed of 2 km/h kills the highest percentage of weeds, and for weed species with unprotected growth points and thin leaves, the first flame application can completely kill weeds with <6 leaves. However, a second or third flame application is required for those with 6 or more leaves. The hot steam method is effective when it is applied twice, with the second application 1 week after the first. However, there is room for improving its technology to make it cost effective for large-scale applications. Mulches after chemical herbicide application are effective for controlling weeds. However, mulching cannot be recommended with flaming because of fire hazard. The effectiveness of herbicide depends on the weed species and on whether the same herbicide was used in the preceding years. Compared to using herbicide with mulching, herbicide alone was less effective in controlling weeds and more costly in terms of cost per hectare and the environment.
We conducted two experiments on Shubenacadie River stock of Morone saxatilis fed trout pellets. E... more We conducted two experiments on Shubenacadie River stock of Morone saxatilis fed trout pellets. Experiment 1 compared juveniles of ca. 40 and 550 g initial body weight in hard freshwater (FW) for 73 days at either 20, 24 or 28 °C. Experiment 2 lasting 115 days compared 40, 300 and 800 g fish in either FW or seawater (SW, 30
HortScience: a publication of the American Society for Horticultural Science
... Tess Astatkie. Nova Scotia Agricultural College, Department of Engineering, PO Box 550, Truro... more ... Tess Astatkie. Nova Scotia Agricultural College, Department of Engineering, PO Box 550, Truro, NS, B2N 5E3, Canada. Dolores Fratesi. Lauren Farms ... samples were dried at room temperature and sent for analysis of residual phyto-available nutrients using the Lancaster soil test ...
Peppermint (Mentha X piperita L.) and spearmint (Mentha spicata L.) are major essential oil crops... more Peppermint (Mentha X piperita L.) and spearmint (Mentha spicata L.) are major essential oil crops in the US and worldwide. The objective of this controlled environment study was to evaluate the effect of three plant hormones (salicylic acid SA, methyl jasmonate MJ, and gibberelic acid GA3, each at 10, 100 and 1000 mg/L, applied as a foliar spray), on biomass yields, essential oil content and oil yields of peppermint and spearmint. Overall, the application of SA at 1000 mg/L increased biomass yields of both mints relative to the control, while the other treatments were not significantly different from the control. The essential oil content was higher in peppermint than in spearmint, and treatments had different effect on the two mint species. The application of MJ at 100 and 1000 mg/L, GA at 10 mg/L, SA at 10 and at 100 mg/L, increased the essential oil content of peppermint, while the oil content of spearmint was not affected by treatments. None of the treatments reduced essential o...
Canadian Journal of Fisheries and Aquatic Sciences, 2005
The potential for sire size to influence life history patterns from fry to sea age at maturity wa... more The potential for sire size to influence life history patterns from fry to sea age at maturity was established by rearing individually identified half-sibs of a single dam and either small (parr) or large (anadromous) sires in a common tank environment. Male sexual maturity was higher among progeny of small versus large sires at both parr (age 0+, 50% versus
Subsurface drainage discharge nitrate-N (NO3-N) losse s were evaluated under corn during a three ... more Subsurface drainage discharge nitrate-N (NO3-N) losse s were evaluated under corn during a three year period under three replicated drainage systems: i) 100 mm diameter drainage tile at 80 cm depth; ii) 50 mm diameter drainage tile at 80 cm depth and iii) 50 mm diameter drainage tile at 50 cm depth. Each drainage system had 72 m spacings between laterals. The field under investigation possessed shallow, imperfectly-to-poorly drained soils. Throughout the investigation average NO3-N concentiations in the drainage outflow were similar for all three systems ranging from 9.6-11.4 mgL-1. Total drainage discharge was significantly lower for the shallow (50 cm) system compared to the two deeper (80 cm) systems. Therefore, significant differences in total NO3-N loss between the shallow (50 cm) and deep (80 cm) systems were observed with shallow systems providing reduced NO3-N losses. Corn yields were significantly lower in the shallow (50 cm) drainage treatment in only one year. Shallow drainage may have many economical and environmental benefits and require further research to evaluate its potential under various soil types. REsUME Les pertes de nitrate-N (NO.-N) pour les dcoulements de drainage souterrains ont 6t6 6va1u6es sous les plantations de mais au cours d'une p6riode de trois ans pour trois systdmes de drainage ayant (,t€ reproduits : i) un tuyau de drainage d'un diamdtre de 100 mm d une profondeur de 80 cm; ii) un tuyau de drainage d'un diamitre de 50 mm i une profondeur de 80 cm et iii) un tuyau de drainage d'un diamdtre de 50 mm ) une profondeur de 50 cm. Chaque systdme de drainage comportait un espacement de L2 m entre les canalisations secondaires. dtudi6 possddait des sols de faible profondeur dont 1e drainage allait d'imparfait d pidtre. Tout au long de 1'6tude, 1es concentrations de NO3-N moyennes dans le d6bit de drainage 6taient semblables pour 1es trois systdmes, al1ant de 9,6 d.71,,4 mg L-1. Le d6bit de drainage total 6tait consid6rablement moins 61ev6 pour le systdme de faible profondeur (50 cm) comparativement aux deux systdmes plus profonds (80 cm), Par cons6quent, des 6carts consid6rables dans la perte de NO3-N totale entre le systdme de faible profondeur (50 cm) et les systdmes profonds (80 cm) ont 6t6 observ6s, Ie systdme de faible profondeur offrant des pertes de NO.-N rdduites. Le rendement des plantations de mais 6tait consid6rablement plus faible dans le traitement de drainage (50 cm) en l'espace d un an seulement. Le drainage i faible profondeur peut pr6senter de nombreux avantages sur les plans 6conomique et environnemental. Il demande de plus amples recherches afin d'6valuer ses possibilit6s en fonction de divers types de sol.
a b s t r a c t 'Native' spearmint (Mentha spicata L.) is one of the two spearmint species grown ... more a b s t r a c t 'Native' spearmint (Mentha spicata L.) is one of the two spearmint species grown commercially in the United States and other countries for essential oil production. The two major constituents of spearmint oil are carvone and limonene. It is not known if the essential oil yield (content) and composition of spearmint oil are affected by diurnal variation, and when it would be the best time for harvesting flowering spearmints within a 24 h period. Therefore, the objective of this study was to evaluate the effect of diurnal variation on yield and composition of spearmint 'Native' essential oil for the environmental conditions of Northern Wyoming, at elevation 1170 m above the sea level. The experiment was conducted on a 3-year old well established spearmint plantation. The harvest times were every 2 h within a
ABSTRACT The objectives of this study were to determine the effects of distillation time (DT; 15–... more ABSTRACT The objectives of this study were to determine the effects of distillation time (DT; 15–1080 min) on yield, composition, and antioxidant capacity of fennel (Foeniculum vulgare) seed essential oil (EO) as well as on the yield, composition, and properties of lipids extracted from steam-distilled fennel seeds (15–600 min). EO yield increased with increasing DT to a maximum of 1.375% at 1080 min. The principal constituent was estragole, comprising 82–91% of the overall content. Other species included limonene, fenchone, and anethole. Antioxidant capacity of the EO was essentially unaffected by DT, with capacities ranging from 11.2 to 20.6 μmol Trolox/g. The yield of lipids extracted from steam distilled fennel seeds was unaffected by DT and ranged from 21.7 to 22.8 mass%. The fatty acid composition was also unaffected by DT, and the major constituents were petroselenic (67.0–71.3%) and oleic (12.0–16.4%) acids. The concentrations of tocopherols, tocotrienols, and phytosterols were unaffected by DT whereas unsaponifiables and EO content in lipids decreased with increasing DT. Acid value, kinematic viscosity, peroxide value, and pour point increased with increasing DT, whereas density decreased. Induction period, heteroatom content, and Gardner color were unaffected by DT. As DT increased, in vitro degradability of defatted, steam-distilled fennel seeds decreased. In summary, longer DT negatively impacted feed quality of steam-distilled, defatted seed meal and lipid quality but did not significantly affect EO composition and antioxidant capacity.
Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce ... more Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce the pressure and to release the methane, the water needs to be pumped out. The resulting waste water is known as coal bed methane water (CBMW). Major concerns with the use of CBMW are its high concentrations of S, Na, dissolved Ca, Mg, SO, and bicarbonate (HCO). Irrigation water is a scarce resource in most of the western states. The objective of this study was to evaluate the effect of various amounts of CBMW on the growth, essential oil content, composition, and antioxidant activity of spearmint ( L.) and peppermint ( L.) crops that were irrigated with the water. These two crops are grown in some western states and are potential specialty crops to Wyoming farmers. The irrigation treatments were 0% CBMW (tap water only), 25% CBMW (25% CBMW plus 75% tap water), 50% CBMW (50% CBMW and 50% tap water), 75% CBMW (75% CBMW plus 25% tap water), and 100% CBMW. Analyses of the data revealed that the CBMW treatments did not affect the antioxidant capacity of spearmint or peppermint oil (242 and 377 μmol L Trolox g, respectively) or their major oil constituents (carvone or menthol). Coal bed methane water at 100% increased total phenols and total flavonoids in spearmint but not in peppermint. Coal bed methane water also affected oil content in peppermint but not in spearmint. Spearmint and peppermint could be watered with CBMW at 50% without suppression of fresh herbage yields. However, CBMW at 75 and 100% reduced fresh herbage yields of both crops and oil yields of peppermint relative to the control.
Historical development of nonlinear stochastic modeling of streamflows is discussed. Physical con... more Historical development of nonlinear stochastic modeling of streamflows is discussed. Physical considerations and graphical investigations of daily streamflows revealed that air temperature and state of basin storage are the most important sources of nonlinearity in catchments with seasonal snow accumulation. The average temperature for the preceding three days, and the flow one or two days earlier were adequate proxies for the temperature and storage conditions of a catchment. The Nested Threshold Autoregressive (NeTAR) model, which considers these sources of nonlinearity simultaneously, was applied to two years of daily flows of the Oldrnan River near Brocket in Alberta, Canada. A third year of daily data was used fbr validating the model. The final NeTAR model provided useful insights into the dynamics of this streamflow system.
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