Claude D. Caldwell

The effect of cultivar and applied nitrogen on the performance of Camelina sativa L. in the Maritime Provinces of Canada

Worldwide, oilseed demand is steadily expanding. This study assessed the novel oilseed crop Camelina sativa L. in the Maritime Provinces of Canada. Evaluations of cultivar and applied N were performed at Truro, NS, Harrington, PEI, and Hartland, NB, in 2005 and 2006. The results show that the selection of cultivar is an important determinant for the potential success or failure of C. sativa production. Differences in plant stand, plant height, seed yield, oil content and fatty acid profile were found among the cultivars. The cultivar Calena provided the most consistent performance in terms of plant establishment, yield and oil content across all year-sites. Plant height, seed yield, oil content, total plant N and seed protein all responded to applied N rate. Applied N increased the seed yield of C. sativa, but the increase was not significant when the application rates were over 60 kg N ha-1 in NS or 80 kg N ha-1 in PEI. Plant height, total N content in plant tissue and seed protein content increased with...

The effect of seeding rate, seeding date and seeder type on the performance of Camelina sativa L. in the Maritime Provinces of Canada

The hypothesis of this study was that spring camelina (Camelina sativa L.) could be grown as a high-value crop under the moist, cool conditions of the Maritime Provinces in Canada and seeding date, seeding rate, and type of seeder will modify productivity and oil composition. The objectives were (1) to determine the optimum seeding date and seeding rate for camelina production in the Maritimes; and (2) to evaluate the effect of seeder type (seed drill and forage seeder) on camelina establishment and seed yield. A seeding date and rate experiment and a seeder type and seeding rate experiment were conducted in 2005 and 2006 in Nova Scotia and Prince Edwards Island. Seeding date did not affect camelina emergence, plant height, seed yield and oil content. The earlier seeding date increased the concentration of stearic acid in the oil compared with the later seeding date. Seed yield of camelina was not affected by seeding rate in the seeder type by rate trial but higher yields were observed up to 600 seeds m-2...

Camelina seed quality in response to applied nitrogen, genotype and environment

Jiang, Y., Caldwell, C. D. and Falk, K. C. 2014. Camelina seed quality in response to applied nitrogen, genotype and environment. Can. J. Plant Sci. 94: 971-980. Camelina (Camelina sativa L.), Brassicaceae, has great potential for food and industrial use. This study analyzed the seed oil content, oil yield, protein content, protein yield, as well as fatty acid profile relative to varying nitrogen (N) rates and in different genotypes under several environmental conditions. Seed samples were obtained from a 2-yr field study with five environments (site-years), five genotypes, and six N rates. Applied N increased protein content, protein yield, oil yield, and polyunsaturated fatty acids (PUFA), but decreased oil content and monounsaturated fatty acids (MUFA). Saturated fatty acids did not respond consistently to applied N. Lower air temperatures during the reproductive stages increased the total seed oil content, but the fatty acid composition was not affected. The experimental line CDI007 had the highest oil content, oil yield, protein yield, and PUFA, but contained the lowest protein content and MUFA. CDI002 contained the highest protein content and PUFA. CDI005 had the highest amount of MUFA. CDI008 was not considered to be a promising genotype since it had the lowest oil content and highest amount of saturated fatty acids.

Soybean nodule hydrogen metabolism affects soil hydrogen uptake and growth of rotation crops

To test the beneficial effect on the following crop of hydrogen released by Hup− soybean nodules, soybean was inoculated with either a Hup− (JH47) or a Hup+ (JH) strain of Bradyrhizobium japonicum. These isogenic strains differ only in that JH47 has a Tn5 inserted in the gene coding for the small hydrogenase subunit which eliminates hydrogenase activity; thus when present in soybean nodules, hydrogen is released into the rhizosphere. Inoculated alfalfa plants were used as the positive control as no hydrogenase activity has ever been found in alfalfa nodules. Soil adjacent to hydrogen releasing (Hup−strain) legume nodules had a significantly higher hydrogen uptake rate than that around the nodules containing the Hup+ strain. Barley grown following soybean inoculated with the Hup− strain exhibited an increased grain yield under field conditions. Key words: Soil, hydrogen oxidization, rotation benefit

Water-stress and N-nutrition effects on photosynthesis and growth of Brassica carinata

Effects of water and nitrogen (N) supply on growth and photosynthetic response of B. carinata were examined in this study. Plant growth and related characteristics varied significantly in response to the availability of water and nitrogen. B. carinata maximized the utilization efficiency of the most limiting resources by developing physiological adaptations, such as changes in root and leaf development. The utilization of water and N was tightly linked with the availability of each resource. Instantaneous water-use efficiency (WUE) was always greater in plants with high-N nutrition [50, 100, and 150 kg(N) ha−1] than in the low-N-treated plants [0 kg(N) ha−1] in all watering treatments. Instantaneous N-use efficiency (PNUE) decreased significantly with increasing water stress in all N treatments. Seed yield is significantly related to PNUE (p>0.05) but not WUE (p<0.05). The positive relationship between leaf net photosynthetic rate (PN) and seed yield suggests that PN can be used as an important tool for selection of new strains with high seed yield.

Photosynthetic and growth responses of Camelina sativa (L.) Crantz to varying nitrogen and soil water status

Water and nitrogen (N) deficiency are two major constraints limiting the yield and quality of many oilseed crops worldwide. This study was designed to assess the response of Camelina sativa (L.) Crantz to the availability of N and water resources on photosynthesis and yield parameters. All the measured variables, which included plant height, root and shoot dry matter, root:shoot ratio, xylem pressure potential (XPP), yield components, photosynthetic parameters, and instantaneous water-use efficiency (WUE) were remarkably influenced by water and nitrogen supply. Net photosynthetic rate (PN) and yield components were significantly decreased more by water deficit than by N deficiency. XPP, stomatal conductance (gs), and intercellular CO2 concentration (Ci) decreased substantially as the water deficit increased irrespective of the level of N application. WUE at the high N supply [100 and 150 kg(N) ha−1] dropped in a large degree as the increased water deficit due to a larger decrease in PN than transpiration rate (E). The results of this study suggest that the regulative capacity of N supply on photosynthetic and plant growth response is significantly affected by soil water status and C. sativa is more sensitive to water deficit than N supply.

Influence of seeding date and harvest stage on yields and essential oil composition of three cultivars of dill (Anethum graveolens L.) grown in Nova Scotia

Experiments were conducted in two locations in Nova Scotia, Canning and Truro, during 2001 and 2002 to determine the effect of seeding date and harvest stage on productivity and composition of essential oil from Anethum graveolens L. ‘Mesten, Dukat’ and ‘Hercules’. Delayed seeding generally reduced yields and altered the concentration of some essential oil components. Both dill seed and dill weed oil from this study had compositions similar to commercially available oil and reported dill oil compositions. The seed oil had moderate to high carvone content (17.9–64.0%) as is desired for the international market. Carvone content in oil increased as the plants matured. Lower yields and essential oil yields were obtained from cv. Hercules compared with the other two cultivars. Herbage yields and essential oil content were typical for the plant species; seed yields were below average, but there is potential to increase these yields through different seeding dates, harvest dates and investigation into optimum nu...

Effect of nitrogen fertilization on camelina seed yield, yield components, and downy mildew infection.

Camelina [Camelina sativa (L.) Crantz] has potential in aquaculture, livestock feed production, and the biofuel industry. It is necessary to determine the appropriate production technology for the newly introduced crop under different environmental conditions. The objective of this 2-year study was to measure the response of five camelina genotypes in terms of seed yield, yield components, and disease incidence to applied nitrogen (N) at multiple sites in the Maritime provinces of eastern Canada. The factorial experiment was set up as a randomized complete block design. The two factors were six N rates (0, 25, 50, 100, 150, and 200 kg ha-1 N) and five genotypes of camelina (Calena, CDI002, CDI005, CDI007, and CDI008). The interactive effect of N rates and genotypes was considered. Results showed that camelina, which is usually considered a low-input crop, responded positively to increased applied N at rates up to 200 kg ha-1 N. Seed yield responded differently to applied N rates depending on genotype. Branch and pod development were decisive for seed yield. The advanced line CDI007 had the highest yield potential among the five genotypes. Downy mildew infection was positively correlated with applied N rates; however, seed yield was not significantly affected by downy mildew infection.

Critical Tissue Identification and Soil-Plant Nutrient Relationships in Dicer Carrot

Abstract Fertility management has been a major concern for carrot growers because there has been little or no yield response to fertilizer application in various trials, even when fertilizer is based on soil test recommendations. Tissue testing may be an appropriate method to manage fertilizer applications to carrots. A greenhouse trial was conducted to identify critical tissue(s) at various growth stages that correlate with yield, establish relationships between nutrient concentrations of critical tissue(s) and nutrient concentrations in soil, and establish relationships among nutrient concentrations of critical tissue(s), nutrient concentrations in soil, and yield. Critical tissues varied for each nutrient studied at each growth stage. Correlations revealed significant relationships between nutrient concentrations of critical tissues and soil largely at active bulking but very few at initiation of bulking. Trend graphs revealed tissue zinc (Zn) concentration had the strongest relationship with yield. There was a significant difference in root fresh weight (RFW) with nitrogen (N) at 100 µg/g, significantly higher than at 0, 300, 350, and 400 µg/g. Greenhouse results suggest fertilizer with an N equivalent of 100 µg/g optimized yields.

Leaf Tissue Testing and Soil and Plant Tissue Relationships for Nitrogen Management in Carrots

Abstract Nitrogen (N) management in carrot (Daucus carota L. var sativus) production systems is critical for increasing efficiency of crop production, decreasing costs, and decreasing nitrate leaching losses to groundwater. Leaf tissue testing may be an appropriate method to monitor and meet carrot N requirements. A field trial was conducted in three locations to 1) determine if “critical tissues” identified in previous research are appropriate for leaf tissue testing in N management of carrots, 2) determine the effects of various N regimes on soil and tissue N concentrations, 3) describe the relationships among soil N concentrations, tissue N concentrations, and yield for several N regimes, and 4) study the effects of N regimes on growth, yield, and recovery of marketable grades of carrots. Nitrogen critical tissues for leaf tissue testing were not useful in N management. Overall, results showed no significant differences in soil and tissue N levels due to increasing N regimes. Correlations among soil, tissue, and yield differed at each harvest but most were not significant. N concentration was higher in soils at a depth of 0–15 cm compared to 15–30 cm. Total N concentrations in tissues decreased over sequential harvests. No clear relationships emerged comparing tissue NO3‐N to soil N measurements over the entire growing season. There were no significant differences in growth and yield of carrots in response to N regimes. Interestingly, a N rate of 0 kg/ha had significantly more fancy‐grade carrots than a N rate of 200 kg/ha. There were no significant differences in culls due to increasing N application.