Crop Diversification Center South

Brooks, Canada

Crop Diversification Center South

Brooks, Canada
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Harms T.E.,Rural Water Branch | Konschuh M.N.,Crop Diversification Center South
Agricultural Water Management | Year: 2010

Current agronomic practices for potato production in the irrigated areas of southern Alberta involve a hill/furrow configuration that was adopted from elsewhere, and designed to shed rainfall away from the hill and into the furrow. However, the principal intent of supplemental irrigation is to capture as much of the applied water into the hill, where the potato tubers and roots are located, and minimize water accumulating in the furrow. A three-year project began in 2006 to quantify the potential irrigation water savings of altered hill shapes for potato production. The three treatments (standard hill, flat-topped hill, and double-planted wide-bed) were arranged in a randomized strip plot design replicated four times. Soil water in each treatment was generally kept between 60 and 90% of available. A fourth treatment, triple-planted wide bed, was added to the project in 2008. The irrigation requirements to maintain the treatments were 487, 442, and 449 mm for the standard hill, flat-topped hill, and double-planted bed, respectively, in 2006 and 442, 408 and 411 mm for the same treatments in 2007. This translates into approximately 10% less irrigation water required for the flat-topped hill shape compared to the standard hill shape. The flat-topped hill shape required 5.0% more irrigation than the standard hill in 2008, but the double and triple-planted wide beds required 8.0 and 9.9%, respectively, less irrigation water than the standard. Although not always statistically significant, water use efficiency was greater in all years for the altered bed shapes compared to the standard hill geometry. Greater water use efficiency can be interpreted as more of the applied water infiltrated into the hill, where the potato plant could use it for transpiration and tuber development. Total yield was greater in 2006 for both the flat-topped hill (72.3 Mg ha -1) and wide-bed hill (69.2 Mg ha -1) compared to the standard hill (61.4 Mg ha -1); however, the treatments were not significantly different. Significantly greater marketable yield was realized from the flat-topped hill treatment in 2006. This treatment also had a significantly greater number of marketable size tubers. In 2007, there were no significant differences in total yield; however, the standard and flat-topped treatments had a significantly greater number and yield of tubers in the 113-170 g size category. Significant differences in total yield were found in 2008. The triple-planted wide bed had significantly greater yield in the smaller size categories compared to the standard treatment and significantly greater total tuber numbers than the other treatments, but the increase was in the smaller size categories, less than 170 g. There were no significant differences among the treatments in yield or total number of tubers in the size categories greater than 171 g in 2008. © 2010 Elsevier B.V. All rights reserved.


Bennett D.R.,Alberta Agriculture and Rural Development | Harms T.E.,Crop Diversification Center South
Canadian Water Resources Journal | Year: 2011

Water supplies available for irrigation in southern Alberta are limited. A study was conducted in southern Alberta to develop crop yield and evapotranspiration (ET c) relationships for major irrigated crops based on current maximum potential crop yield data and improved methods for determination of crop evapotranspiration. Production functions for crop yield and the field water supply, which includes irrigation at 80% efficiency, effective precipitation, and stored soil moisture depletion, were subsequently determined. These empirical relationships may be used by water managers, economists, and producers to examine the economic implications of crop yield reductions from water stress due to limited water supplies, less than optimum (deficit) irrigation management, or variation in evaporative demand from year to year in different agro-climatic areas of southern Alberta. Potential yield estimates for different scenarios may be used with relevant economic information to determine optimum water use for irrigation. © 2011 Canadian Water Resources Association.


Bennett D.R.,Alberta Agriculture and Rural Development | Harms T.E.,Crop Diversification Center South | Entz T.,Agriculture and Agri Food Canada
Canadian Water Resources Journal | Year: 2014

Weather variability has a profound influence on crop and irrigation water requirements. Estimates of crop evapotranspiration (ETc) and net irrigation water requirements are needed for water allocation, risk management and irrigation system planning. Seasonal ETc and net irrigation water requirement estimates based on the standardized Penman-Monteith method were examined through frequency analysis of historical weather data. Seasonal ETc calculated using the Penman-Monteith equation is based on daily solar radiation, air temperature, relative humidity, and wind speed. Historical weather data from 1983 to 2012 at Lethbridge and Vauxhall were used to determine seasonal ETc, seasonal precipitation and net irrigation water requirements for 11 major (most prevalent) irrigated crops in southern Alberta. Seasonal ETc was consistently greater at Lethbridge than Vauxhall, whereas seasonal precipitation was generally less at Vauxhall than Lethbridge for all major crops. Mean seasonal ETc ranged from 355 mm for barley silage at Vauxhall to 728 mm for alfalfa hay at Lethbridge at a 10% chance of exceedance. Mean net irrigation water requirements ranged from 273 mm for barley silage at Vauxhall to 526 mm for alfalfa hay at Lethbridge at a 10% chance of exceedance. Area-weighted seasonal ETc demand within the irrigation districts is currently about 500 mm (2.8 billion m3) and the net irrigation water requirement within the irrigation districts is at least 380 mm (2.1 billion m3) at a 10% chance of exceedance. Annual gross diversion requirements for the irrigation districts could approach the licensed water allocation limit of 3.45 billion m3 at a 10% chance of exceedance when conveyance losses, irrigation system application efficiencies, and current irrigation management practices are considered. The frequency with which annual gross irrigation water requirements approach or exceed this licensed water allocation limit may increase in the future with climate change in southern Alberta. © 2014 Canadian Water Resources Association.


Hwang S.-F.,Crop Diversification Center North | Strelkov S.E.,University of Alberta | Feng J.,Crop Diversification Center North | Gossen B.D.,Agriculture and Agri Food Canada | Howard R.J.,Crop Diversification Center South
Molecular Plant Pathology | Year: 2012

Plasmodiophora brassicae causes clubroot disease in cruciferous plants, and is an emerging threat to Canadian canola (Brassica napus) production. This review focuses on recent studies into the pathogenic diversity of P. brassicae populations, mechanisms of pathogenesis and resistance, and the development of diagnostic tests for pathogen detection and quantification. Taxonomy: Plasmodiophora brassicae is a soil-borne, obligate parasite within the class Phytomyxea (plasmodiophorids) of the protist supergroup Rhizaria. Disease symptoms: Clubroot development is characterized by the formation of club-shaped galls on the roots of affected plants. Above-ground symptoms include wilting, stunting, yellowing and premature senescence. Disease cycle: Plasmodiophora brassicae first infects the root hairs, producing motile zoospores that invade the cortical tissue. Secondary plasmodia form within the root cortex and, by triggering the expression of genes involved in the production of auxins, cytokinins and other plant growth regulators, divert a substantial proportion of plant resources into hypertrophic growth of the root tissues, resulting in the formation of galls. The secondary plasmodia are cleaved into millions of resting spores and the root galls quickly disintegrate, releasing long-lived resting spores into the soil. A serine protease, PRO1, has been shown to trigger resting spore germination. Physiological specialization: Physiological specialization occurs in populations of P. brassicae, and various host differential sets, consisting of different collections of Brassica genotypes, are used to distinguish among pathotypes of the parasite. Detection and quantification: As P. brassicae cannot be cultured, bioassays with bait plants were traditionally used to detect the pathogen in the soil. More recent innovations for the detection and quantification of P. brassicae include the use of antibodies, quantitative polymerase chain reaction (qPCR) and qPCR in conjunction with signature fatty acid analysis, all of which are more sensitive than bioassays. Resistance in canola: Clubroot-resistant canola hybrids, recently introduced into the Canadian market, represent an important new tool for clubroot management in this crop. Genetic resistance must be carefully managed, however, as it has been quickly overcome in other regions. At least three resistance genes and one or two quantitative trait loci are involved in conferring resistance to P. brassicae. Root hair infection still occurs in resistant cultivars, but secondary plasmodia often remain immature and unable to produce resting spores. Fewer cell wall breakages occur in resistant hosts, and spread of the plasmodium through cortical tissue is restricted. More information on the genetics of clubroot resistance in canola is needed to ensure more effective resistance stewardship. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.


Howard R.J.,Crop Diversification Center South | Strelkov And S.E.,University of Alberta | Harding M.W.,Crop Diversification Center South
Canadian Journal of Plant Pathology | Year: 2010

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is an economically important disease affecting plants in the family Brassicaceae worldwide. In Canada, it has mainly been a problem on cruciferous vegetables in the traditional production areas of Ontario, Quebec, British Columbia and the Atlantic Provinces. In the Prairie Provinces, clubroot has been reported sporadically in a few home gardens and commercial vegetable fields in Alberta and Manitoba over the past 80 years; however, this situation changed dramatically with the discovery of 12 infected canola (Brassica napus) fields near Edmonton, AB in 2003. Annual surveys carried out since 2003 have revealed that clubroot is a much more widespread and serious disease in Alberta than initially thought. By 2008, it had been detected in about 410 canola, mustard and vegetable fields in central and southern areas of the province. The Alberta Clubroot Management Plan was developed to guide farmers, agribusinesses, oil and gas companies, contractors, and the general public in adopting good growing practices or taking measures to prevent further spread of this disease. An unprecedented research effort is underway in western Canada to develop a better understanding of the biology and management of clubroot, especially in the canola production systems on the Prairies. These studies are broadly based and include activities such as the improvement of diagnostic tests, determination of P. brassicae pathotypes, investigation of modes of seed and soil transmission, evaluation of fungicide efficacy, soil amendments, biological control agents and equipment sanitation protocols, and modelling disease distribution and risk. Through these efforts, new information is being generated that will give the agricultural industry and other stakeholders some new perspectives on this old disease threat. © 2010 The Canadian Phytopathological Society.


Hwang S.-F.,Crop Diversification Center North | Howard R.J.,Crop Diversification Center South | Strelkov S.E.,University of Alberta | Gossen B.D.,Agriculture and Agri Food Canada | Peng G.,Agriculture and Agri Food Canada
Canadian Journal of Plant Pathology | Year: 2014

Clubroot, caused by Plasmodiophora brassicae, has emerged as a serious disease threatening the canola production industry in western Canada. This review summarizes results from studies, conducted since 2007, on the development of effective strategies for the management of clubroot in canola. Several options have been proposed for the control of this disease in infested fields, including liming the soil to increase soil pH, crop rotation with non-hosts and bait crops, manipulating the sowing date, sanitization of farm equipment, and the deployment of resistant cultivars, all aimed at reducing the severity of infection. Research began by assessing existing clubroot treatments, originally developed for the cole crop vegetable industry, for their applicability to canola production systems. Although these treatments provide good levels of clubroot reduction for the intensive production of short-season brassica vegetables, most are not economically feasible for the large-scale production of canola, which requires protection over a greater field acreage. Genetic resistance to P. brassicae has been shown to be a practical option for the management of clubroot on canola, but resistance stewardship, coupled with crop rotation and appropriate cultural practices, will be required to maintain the performance and durability of genetic resistance. Pathogen resting spores can be disseminated on infested soil carried on both machinery and seed. Efforts to minimize spread of the pathogen between canola fields have focused largely on the sanitization of field equipment and seed. © 2014 © 2014 The Canadian Phytopathological Society.


Dosdall L.M.,University of Alberta | Carcamo H.,Agriculture and Agri Food Canada | Olfert O.,Agriculture and Agri Food Canada | Meers S.,Crop Diversification Center South | And 2 more authors.
Biological Invasions | Year: 2011

Agroecosystems in the western Canadian provinces of Alberta, Saskatchewan, and Manitoba have been invaded by several alien herbivorous insects from several orders and families. These species have caused very substantial reductions in yield and quality of the dominant crops grown in this region, including cereals (primarily wheat, Triticum aestivum L., barley, Hordeum vulgare L., and oats Avena sativa L.), oilseeds (primarily canola, Brassica napus L. and Brassica rapa L., and mustard, Sinapis alba L. and Brassica juncea (L.) Czern.), and pulses (primarily field pea, Pisum sativum L., lentil, Lens culinaris Medik., and chickpea, Cicer arietinum L.). In this study, we used literature searches to identify the major species of insect pests of field crops in western Canada and determine those species indigenous to the region versus species that have invaded from other continents. We summarize invasion patterns of the alien species, and some estimated economic costs of the invasions. We document the invasion and dispersal patterns of the cereal leaf beetle, Oulema melanopus L. (Coleoptera: Chrysomelidae), for the first time in all three provinces. We also report the co-occurrence of its exotic parasitoid, Tetrastichus julis (Walker) (Hymenoptera: Eulophidae), and implications for classical biological control. We present results of field studies describing the dispersal patterns of a second recent invader, the pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae). The implications of invasions in this region are discussed in terms of economic and ecological effects, and challenges posed for pest mitigation. © 2011 Springer Science+Business Media B.V.


Rennie D.C.,University of Alberta | Manolii V.P.,University of Alberta | Cao T.,University of Alberta | Hwang S.F.,Crop Diversification Center North | And 2 more authors.
Plant Pathology | Year: 2011

Using quantitative PCR, DNA of Plasmodiophora brassicae, the causal agent of clubroot, was detected and quantified on canola, pea and wheat seeds, as well as on potato tubers, all harvested from clubroot-infested fields in Alberta, Canada. Quantifiable levels of infestation were found on seven of the 46 samples analysed, and ranged from <1·0×10 3 to 3·4×10 4 resting spores per 10g seeds; the vast majority (80-100%) of resting spores on these samples were viable, as determined by Evan's blue vital staining. However, the levels of infestation found were generally lower than that required to cause consistent clubroot symptoms in greenhouse plant bioassays. While the occurrence of P. brassicae resting spores on seeds and tubers harvested from clubroot-infested fields suggests that seedborne dissemination of this pathogen is possible, practices such as commercial seed cleaning may be sufficient to effectively mitigate this risk. © 2011 The Authors. Plant Pathology © 2011 BSPP.


Nezami A.,Ferdowsi University of Mashhad | Bandara M.S.,Crop Diversification Center South | Gusta L.V.,University of Saskatchewan
Canadian Journal of Plant Science | Year: 2012

Chickpeas (Cicer arietinum L.) are subject to freezing injury and/or winter kill. Field testing for freezing tolerance evaluation is slow, unreliable, and highly variable; thus an artificial freeze test that correlates with field survival is required. Our objective was to develop a reliable and simple artificial freeze test to evaluate the freezing tolerance of winter chickpeas. Four cultivars with varying levels of freezing tolerance were grown and cold acclimated under low irradiance (150 μmol m-2 s-1) and high irradiance (400 μmol m-2 s-1). Acclimated whole plants or excised leaflets were subjected to six tests to determine the LT50 temperature (lowest temperature to kill 50% of the plants). In two tests, following the freeze test, whole plants were held at 20°C/15°C (day/night) for 3 wk for re-growth analysis. LT50 was estimated from both axillary buds and foliage re-growth and from foliage re-growth. The LT50 was also assessed on excised plantlets from whole plants frozen to a series of test temperatures. LT50 was determined by re-growth of plantlets held for 1 wk at 20°C in test tubes or by electrolyte leakage following thawing at 20°C. Excised plantlets were frozen to the same temperatures used for the whole plants. LT50 was determined by re-growth in test tubes for 1 wk or by electrolyte leakage. Results from excised plant parts from frozen intact plants or plantlets excised prior to the freeze test were similar to those estimates derived from re-growth analysis of plants frozen whole. Freeze test employing excised plantlets offers high precision and the ability to screen large populations. Plants grown and cold acclimated under an irradiance of 150 μmol m-2 s-1 were not as freezing tolerant as those grown and cold acclimated under an irradiance of 400 μmol m-2 s-1. © 2011 - Agricultural Institute of Canada.


Hasan M.J.,University of Alberta | Strelkov S.E.,University of Alberta | Howard R.J.,Crop Diversification Center South | Rahman H.,University of Alberta
Canadian Journal of Plant Science | Year: 2012

Clubroot disease of crucifers, caused by Plasmodiophora brassicae, poses a threat to the Canadian canola industry, and the development of resistant cultivars is urgently needed. Germplasm resistant to local pathotype(s) is the prime requirement for breeding clubroot-resistant cultivars. The objective of this study was to identify Brassica germplasm possessing resistance to P. brassicae pathotypes prevalent in Alberta. Pathotype-specific resistance was identified in the diploid species Brassica rapa (AA) and B. oleracea (CC), and in the amphidiploid B. napus (AACC). Among B. rapa genotypes, turnip was the most resistant, followed by winter type and spring type oilseed rape. The rutabaga group of B. napus, on the other hand, was homogeneous for resistance to Canadian P. brassicae pathotypes. The diploid species B. nigra (BB) also showed pathotype-specific resistance. However, the two amphidiploids carrying the B. nigra genome, B. juncea (AABB) and B. carinata (BBCC) were completely susceptible to clubroot.

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