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The Canadian Ornamental Horticulture Alliance is pleased to introduce their first informational video on the function and benefits of Hybrid Treatment Systems, or HTS, an innovative irrigation water treatment technique for use by greenhouse producers and ornamental nurseries. Based on the results of successive research projects by Dr. Ann Huber, this research highlights a novel approach to help growers effectively manage the quality of irrigation water run-off.
Author Archives: Rita Weerdenburg
Vineland is seeking one or more entities to bring further impact and efficiency to their apple breeding program by collaborating in the selection of commercial cultivars and advancing promising apple varieties to both domestic and international markets through various commercialization models. At this time, Vineland is initiating a Request for Expressions of Interest (REOI) to gain a more thorough understanding of both the organizations that may become our future collaborators, as well as the multitude of potential commercialization models that can be applied to apples.
If you are looking to improve your biological and biochemical plant protection strategies, consider Vineland’s new Biological Crop Protection research services. Vineland can support the introduction and use of new products and integrated pest management (IPM) solutions to improve production efficiency while promoting horticulture crop quality, environmental performance and safe working conditions.
For more information or a service quote, contact:
Rose Buitenhuis, PhD
Program Leader, Biological Crop Protection
rose.buitenhuis@vinelandresearch.com
News
Monitoring of spruce spider mite (Oligonychus ununguis) populations in field-grown ornamental cedars and characterization of entomofauna in this environment
30
Jan
Jan
By: IQDHO Plant Health Monitoring Team
One of the major pests affecting ornamental cedars is Oligonychus ununguis (spruce spider mite). It feeds on the chlorophyll of twig cells, causing them to turn yellow and discoloured.
In 2019 and 2020, a project was conducted to develop a screening method for O. ununguis in field-grown ornamental cedar by attempting to correlate a simple method (shaking) with a more extensive method (brushing cedar twigs with a mite brush). The project also aimed to characterize spruce mite population curves during the cedar growing season.
During the 2019 season, entomofauna related to O. ununguis was also studied. Organisms observed included two predatory mites, Anystis baccarum and Typhlodromina citri, and the phytophagous mite Platytetranychus thujae, which was relatively abundant during this summer. In 2020, monitoring of Platytetranychus thujae populations and a study of mites and predators occurring at the same time as spruce spider mites were conducted to better identify which mites cause damage to cedars and the natural enemies of the pest mites present in the same environment.
At the end of these two years, a comparison of the shaking and brushing techniques revealed that shaking provides a relatively accurate estimate of O. ununguis and P. thujae populations.
The phytophagous mite Platytetranychus thujae was present in very large numbers in 2020 in the cedars of one grower. This phytophagous mite may be present in many cedar groves in Quebec, but it is likely to be confused with O. ununguis. It would be interesting to know if this mite behaves exactly like O. ununguis, causing the same damage at the same population density, or if it behaves differently.
This project was carried out as part of the activities of the Réseau Pépinières Ornementales, of the Réseau d’avertissements phytosanitaires, with financial assistance from the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation.
For more details, please refer to the project reports:
30
Jan
Jan
The ever-increasing cost of fertilizer inputs is just one reason why growers of agricultural and horticultural crops in both outdoor and controlled greenhouse growing environments have found it necessary to take a closer look at their application rates and practices. Across Canada, the horticultural sector and especially greenhouse growers have come under additional scrutiny as the possible source of contamination when unacceptable levels of pollutants have been found in nearby streams and ponds. Just as critical, therefore, has been the need to meet increasingly stringent regulations set by environmental agencies to control the quality of irrigation run-off water.
As a result, researchers are now looking to answer the seemingly simple question of “how low can you go,” as part of the solution to both dilemmas which currently face the floriculture greenhouse grower.
A research project currently underway by the University of Guelph’s Dr. Barry Shelp, “Optimizing nutrient delivery in greenhouse-grown potted chrysanthemums: Sub-irrigation and drip irrigation systems” tests the hypothesis that nutrient use can be vastly improved by strategically manipulating the timing of nutrient delivery to the plant. This project is part of the “Accelerating Green Plant Innovation for Environmental and Economic Benefit” Cluster and is funded by the Canadian Ornamental Horticultural Alliance (COHA-ACHO), private sector companies, and the Government of Canada under the Canadian Agricultural Partnership’s AgriScience Program, a federal, provincial, territorial initiative Dr. Shelp’s current project is specifically focused on testing the improved delivery of micro-nutrients to both drip irrigated and sub-irrigated chrysanthemums.
Dr. Barry Shelp
University of Guelph
Commercial trials with different N (left) and NPK (right) rates.
The current project is a continuation of his previous research project under the Growing Forward 2 (2013 – 2018) Cluster program which demonstrated the successful reduction of macronutrient use. In that project, Dr. Shelp was able to verify that the supply of nitrogen, phosphorous, sulfur and potassium could be reduced by as much as 75 to 87.5% compared to current industry standards, without any adverse impacts to crop yield or quality.
The overall premise of his current research, says Dr. Shelp, to test the limits of lowering fertilizer inputs seems very simple. However, far more complex is the understanding of plant physiology and using a plant’s inherent capacity and attributes to inform the decision-making processes about fertilizer application which has shaped the foundation of his hypothesis.
“For many years, and even as a post-doc, I began to understand and marvel at plant characteristics associated with nutrient acquisition and redistribution in the plant. I came to realize that a plant’s source of nutrition changes as the plant grows and develops and if proven to be true, that premise could greatly influence commercial fertilization practices. Although that was many years ago, I am grateful for the circumstances that are finally giving me the opportunity to test my theory.”
Articulating his hypothesis in simple terms, Dr. Shelp explains that young plants absorb nutrients through the root system, but that changes as the plant matures. Plants then start to use previously acquired and stored nutrients and use them for fruit and flower development. By strategically lowering the nutrition rates, plants can be induced to better absorb nutrients early in the growth cycle and to redistribute their stored resources later in the growth cycle to supply the reproductive parts of the plant.
Rather than continuously supplying a plant with nutrients, Dr. Shelp’s theory calls for an interruption to fertilizer application at a time in a plant’s growth cycle when it has sufficient stored nutrients in the leaves to sustain reproductive growth. Typically, the time is best at the onset of flowering, when the plant transitions from vegetative to reproductive growth, is most efficient at mobilizing nutrients, and the uptake of nutrients through the root system starts to decline. Remarkably, this procedure can be combined with a reduction in nutrient supply to the young plants, and as long as it not excessive, the efficiency of nutrient uptake by the roots is improved so that the plant acquires and stores the same amount of nutrients as with a much higher nutrient supply.
Research trials with different Fe (left) and Zn (right) rates.
Dr. Shelp recognizes the challenges associated with grower adoption of new technologies and growing practices. “Once growers have a formula that works for them, it is understandable that change poses a huge risk.” He is nonetheless confident that it is only a matter of time before growers slowly implement the new and reduced fertilization guidelines based on his research results.
It is a very simple matter to quantify the savings that can be realized through less fertilizer use. It is more difficult to quantify the savings that can be achieved through reduced costs associated with cleansing spent irrigation water, and especially the run-off that occurs with drip irrigation. “It’s difficult to put a value on being able to meet the strict regulations set by environmental agencies, but growers instinctively recognize the benefits are significant.”
Conducted at both the University of Guelph’s experimental greenhouse labs and a Niagara-based commercial greenhouse grower, Dr. Shelp’s research focused on chrysanthemums, using four commonly grown varieties, as they are the largest dollar volume greenhouse floriculture crop grown in Canada. Crops were measured for yield and overall plant quality and nutrient leaf analysis by the University’s Laboratory Services division was used to provide information on the level of micronutrients. To date, Dr. Shelp has worked with sub-irrigation systems because if managed properly, the composition of the excess nutrient solution is essentially unchanged, so it can be recycled and reused. However, he intends to also test his modified delivery strategy with drip irrigation because of its importance in the industry. If the nutrient supply can be reduced, then it should be possible to reduce the overirrigation that is required to prevent salt accumulation in the growing medium, thereby conserving both nutrients and water.
After research validating his theory on the reduced use of macronutrients (nitrogen, phosphorous, potassium, calcium, magnesium and sulfur), Dr. Shelp set out to study the impacts of reducing the use of micronutrients. In separate trials, the project looked at zinc, copper, iron, manganese, boron and molybdenum. Depending on the formulation of the comparative commercial formulas being studied, results showed that delivery of these nutrients can be reduced by 85-95% over the crop cycle without sacrificing plant and flower quality.
The significance of the research results, says Dr. Shelp, point to several logical “next-step” applications, including outdoor production of ornamental floriculture crops and possibly controlled environment production of edible crops.
Optimized macronutrient delivery during vegetative growth.
Acceptable leaf macronutrient status with optimized delivery during vegetative growth.
Flower development unaffected by Mn nutrition during vegetative growth.
Flower development unaffected by Fe nutrition during vegetative growth.
Optimization of micronutrient delivery during vegetative growth.
Acceptable leaf micronutrient delivery during vegetative growth.
An exciting new chapter in urban greening and healthy Canadian landscapes has begun and is centred at Vineland. The new public-private Greening the Landscape Research Consortium to address common urban landscape challenges has launched with an initial cohort of 13 members. Together, consortium participants will set research priorities reflecting industry needs and access training and skills development, innovative data, network connections and emerging knowledge. They will also take part in an urban forestry pilot project.
“One of the key features attractive to members is the opportunity to build a customized case study. One of the challenges in urban forestry is gaps in accessing proper solutions — everyone wants nature-based solutions but how do we do it and what type of information can we rely on?” says Darby McGrath, PhD, Program Leader, Plant Responses and the Environment. “We want to fill those gaps with evidence-based research.”
Projects are now underway and consortium members will have access to case study findings and resources as part of Vineland’s goal to build an information network and a collective capacity for solving common industry challenges. Current consortium partners make up a range of stakeholders from across the industry, such as municipalities, government, conservation authorities, non-governmental organizations, professional associations, suppliers, nurseries, landscape professionals, developers and consultants. A new membership intake will open in spring 2022. “The reason for joining the consortium is different for each member and is related to where they fit in the industry. For some, what is important is being able to test and solve a real problem and create a value proposition in their area,” adds McGrath. “For others, it’s to access information and learn more about what others are doing.”
Update from Vineland Research and Innovation Centre
Vineland has discovered a new general predator to help control pests associated with increased crop diversity in Canadian greenhouses, thanks to a five-year project funded in part by the Government of Canada under the Canadian Agricultural Partnership’s Agri-Science Program, in collaboration with the Université du Québec à Montréal (UQAM) and the biocontrol producer Applied Bio-nomics Ltd.
According to Rose Buitenhuis, Vineland’s Senior Research Scientist, Biological Control, the new predator Anystis is effective against several key greenhouse pests by controlling thrips and spider mites and suppressing aphis.
An updated report on the COHA project “Optimizing turfgrass fertilization to reduce nitrate losses” by Dr. Guillaume Gregoire of Laval University is now available in the Journal of Environmental Quality.
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Oct
Oct
Snow moulds cause serious problems in turf grass in regions where the winters are cold and turf is snow covered. These pathogens cause patches of discoloured and water-soaked grass and delay turf recovery after winter which, in turn, reduces the quality of the turf and playability on golf courses. It is estimated that golf courses in the Pacific Northwest spend approximately $20,000 annually on fungicides for the control of snow mould diseases.
Pink snow mould, Microdochium nivale, is one of the most common snow moulds affecting turf grass in Western Canada. This pathogen does not require snow cover in the winter to facilitate disease progression and can be active all year long in areas with cool, wet climates.
The search for alternative methods for the control of snow mould has been ongoing for several decades. The rise in pesticide bans and restrictions have made it difficult for turf management that relies heavily on the use of fungicides to control this disease. Several biological agents have been investigated for the control of snow moulds, including Typhula phacorrhiza, Pseudomonas aureofaciens and Trichoderma atrovirid.
A research study was conducted by Dr. Deborah Henderson at the Institute for Sustainable Horticulture at Kwantlen Polytechnical Institute to investigate the efficacy of Trichoderma fungal biocontrol agents for the control of snow mould disease in turf grass. Dr. Henderson notes that as the research resulted in as many questions as answers, further study will be required to determine how biocontrols can be more effectively employed in the management of this pathogen.
By: Émilie Lemaire, Agr, M.Sc., Project Manager, IQDHO
Nitrogen is the most important nutrient for plant growth. Soil can only partially meet the needs of plants for this element, and the proportion varies from one soil to another, depending on several factors. Therefore, nurserymen who grow ornamental deciduous and coniferous trees in the field mostly use mineral nitrogen fertilizers (MNF) to meet the needs of their crops.
The use of MNFs generates greenhouse gas (GHG) emissions directly through the denitrification of inorganic nitrogen in the field (N2O), and through the fuel consumption (CO2) associated with the application of the fertilizer. Good MNF management is essential to reduce losses to the environment. Fractionating applications and synchronizing them with crop needs are ways to maximize plant uptake and reduce losses to the environment.
In field grown woody ornamental plants, the most common fertilization practice today is to split the annual nitrogen application into three applications of mineral fertilizer (May, June, July). Fall nitrogen fertilization is still not widely used because of a popular belief that late nitrogen application can interfere with winter hardening of plants. Nevertheless, this approach may be more beneficial in several ways. The tendency is that soil temperatures and metabolic activity of trees are higher in early fall than in early May. These conditions are more advantageous for nitrogen uptake by the roots. The nitrogen taken will be stored for the winter and quickly available the following spring. In fact, for several species, nitrogen remobilization in the tree for growth in the spring occurs before root activity resumes and nitrogen is withdrawn from the soil. The accumulation of reserves is most advantageous for species that have only one rapid growth phase in the spring.
Oak trees from the fall fertilization trial.
Source: IQDHO
Measuring the diameter of the trunk with a caliper.
Source: IQDHO
IQDHO conducted a project to study the effect of early spring and fall mineral nitrogen fertilization on plant growth, quality, nitrogen content and winter survival under Quebec conditions. This project also aimed to evaluate whether improved nitrogen removal applied in the fall rather than in the spring could reduce the current annual application rate and thus reduce GHG emissions. Fertilization treatments were tested on lilacs (Syringa reticulata “Ivory Silk”), oaks (Quercus rubra) and cedars (Thuja occidentalis) for two years.
Data collected did not show that nitrogen uptake and growth were increased following fall (September and October) nitrogen fertilization compared to spring (May). In fact, at the end of the project, there were no noticeable differences between trees in the different fertilization treatments, even for those that received a 50 kg nitrogen (N) per hectare (ha) lower annual rate.
Therefore, the results suggest that nitrogen application could be reduced on certain sites without significantly compromising the yield and quality of some ornamental woody plant species. With the elimination of 50 kg N/ha, nurserymen could reduce GHG emissions by approximately 807 kg CO2e/ha. However, the drought of 2020 greatly affected the growth of all trees and possibly reduced the response of the trees to the various fertilization treatments. Thus, the project will have raised doubts about the usefulness of an annual rate of 150 kg N/ha and demonstrated the potential to reduce GHG emissions by reducing the rate, but results across more sites, species and years will be needed to ascertain the nitrogen requirements of the many woody ornamentals grown in the field.
Nevertheless, the project addressed one of the main concerns of nurserymen and crop consultants regarding fall fertilization. There was no increased winter injury in fall fertilized trees. Therefore, this fertilization method would be safe, at least for these three species.
For more details, see the project’s final report:
https://www.iqdho.com/images/stories/projets/RF_16-GES-13_IQDHO.pdf
See the summary sheet:
https://www.iqdho.com/images/stories/projets/Fichesynthese-16-GES-13%20IQDHO.pdf
“This project was carried out as part of component 4 of the 2013–2018 Prime-Vert Program with financial assistance from the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation (MAPAQ) through the 2013–2020 Climate Change Action Plan.”
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