Recent Projects

2.3 Proposed Technology-based Products, Processes, and Services

            Anticipated deliverables obtained from the proposed research include a new field sanitation system to greatly reduce weed, disease and insect infestations hindering wild blueberry production.  In addition, this system will help reduce pesticide usage and resistance in wild blueberry fields throughout Canada and the United States (predominately Maine). The field-level, environment and plant sensing systems developed will allow for assessments of abiotic (e.g., soil moisture) and biotic (weed, disease and insect pressures and canopy cover, height and yield potential) factors influencing the crop, giving key information to make sound management decisions. Integration of these data into higher tier processing operations should greatly improve equipment operational efficiency and harvested product tracking, to meter-level accuracy within a field.

Microwave Field Sanitation Technologies.
            Microwave energy has been proposed as a possible solution to varied problems in agriculture, including pest management; many species of weeds, nematodes, fungal pathogens and soil-borne insects have been successfully controlled, in practice, with microwave machines. Potential applications of the technology for in-field pest control are intriguing given its rapid penetration into “the load” (e.g. soil, leaves, stems), lack of residue after application, long lasting control, targeted application, and demonstrated safety to non-target soil microflora.

            Previous work with wood and stored grain products showed that non-ionizing microwave irradiation, either in stationary or conveyer belt systems can be a feasible alternative to conventional kiln ovens or methyl bromide fumigation for phytosanitation. Pest management researchers at NSAC and AAFC will work with engineers at NSAC and Doug Bragg Enterprises to investigate the potential to develop industrial scale-up of microwave energy as a tool to sterilize blueberry field plant debris infested with insect and disease pests. We predict that this technology will not only prove useful to the wild blueberry industry, but other industries as well that suffer from pest infested materials, including local lumber and fruit industries.

2.3.2 Technology Based Processes

Pest Management through Field Sanitation.
            Field sanitation is has proved an invaluable strategy to reduce or eliminate pests in many agricultural systems, and was recently stated at an AAFCC Pest Management/Pesticide Management Regulatory Agency Resistance Management Workshop as being an essential component for agricultural production practices. Researchers from NSAC and AAFC will conduct research to establish: (1) the basic worth of field sanitation in wild blueberry fields; and (2) the most promising technological alternatives for field sanitation in wild blueberry agroecosystems. The successful implementation of this process should lead to greatly reduced reliance on broad-spectrum pesticides, along with identification and improved use of efficacious bio-rational pest control technologies to enhance environmental stewardship and food safety.  Fortuitously, the program’s unique approach of targeting pests in the fall also fits well into an important pesticide resistance management program and should therefore, prolong the efficacy of environmentally safe compounds and avoid superfluous pesticide applications. The use of these new products will be further reduced through a variable rate pesticide applicator that only applies the pesticides to predetermined “targeted areas,” thereby minimizing blanket applications of pesticides to fields. All of these research efforts are crucial to secure expanding foreign markets with increasing chemical restrictions (e.g. Japan and the European Union).  Overall, it is anticipated that this will put the Canadian blueberry industry in a better position with international competition, especially producers from the United States, who have access
to many more registered pesticides including bio-pesticides that are safer and more environmentally friendly. 

Integrated Disease Management. 
            The predominate goal of an integrated disease management program is to consistently (i.e., year to year basis) provide a commercially acceptable level of disease control by integrating all available control technologies into one program. To achieve this, a wild blueberry disease management program must integrate the knowledge of the pathogen and disease biology, timely application of fungicides or biological control agents, and the use of cultural management practices.  The causal organisms and disease basic biology of most wild blueberry diseases including floral (Monilinia and Botrytis) and stem (Godronia and Phomopsis) blights and leaf spot diseases (Septoria, rust and Valdensinia) are known (Caruso and Ramsdell, 1995), and associated control measures exist with approved fungicides and/or biological control agents for most floral and stem blights and more recently foliar diseases (as part of the current AIF project).  However, the presence of cultural management technologies to suppress the leaf diseases Septoria and rust in wild blueberries is nonexistent, and there a strong desire in the Bragg Food Group of companies and in the wild blueberry industry in general, to develop an integrated process that minimizes reliance on “old chemistry” (chlorothalonil) protective fungicides and their residues in harvested berries.

            It is proposed to develop cultural management technologies to mitigate foliar diseases (Septoria and rust) that can subsequently become part of an integrated disease management process for wild blueberry production. The initial emphasis will be on (1) the assessment of foliar-applied polyphosphonate compounds used alone or in conjunction with reduced risk fungicides (foundation work for this commenced in 2006 and is continuing), and also (ii) the use of foliar and/or soil applied silicone compounds. Si is effective in controlling diseases caused by fungi and bacteria including leaf and neck blast in rice, incidence of powdery mildew in cucumber, barley and wheat; rust in cowpea and leaf spot in Bermuda grass. Given the low soil Si levels in wild blueberry soils, antidotal evidence of beneficial impacts of Si applications in wild blueberry fields , and the impact of Si on the physiology of selected plants with respect to the physical structure (i.e., cuticular membrane) and host resistance in plants, it is postulated that application(s) of Si may sufficiently increase host resistance to a level where the premature defoliation caused by Septoria and rust will no longer be above economic threshold values.  Combined with the use of field sanitation techniques (which will reduce initial innoculum sources on leaf and stem litter) and reduced risk fungicides presently in the process of being commercialized for use in the wild blueberry industry (e.g., LEM penthiopyrad), it is speculated that the use of these technologies in an integrated disease management program will reduce the reliance of fungicide applications.

2.6 Incremental Nature of the Project

         Oxford is in the final year of a 6 year (2004 to 2010), $3.5 million initiative that has focused on the development of environmental monitoring and precision farming technologies for use in the wild blueberry and processing carrot production. Within the project, emphasis has been placed on (i) developing remote sensing and field level hypersectral technologies to assess vegetative cover in blueberry fields; (ii) developing protocols and accessing potential groundwater sources for supplementary irrigation; (iii) assessing new reduced risk fungicides and herbicides to be integrated into integrated pest management practices; (iv) evaluating new nutrient sources for wild blueberry production and developing improved nutrient management practices; (v) developing variable rate application capabilities of agrochemicals; and (vi) stress assessment and remediation including the development of an agroinfomatics system for carrot production and an intelligent irrigation system for wild blueberries. 

         Prior to the present research initiative, there was a reliance on the use of burning to prune fields to reduce pest pressures prior to the onset of a production cycle (i.e., following October or November after harvest), blanket application of fertilizers and pesticides in fields, and also the reliance of “old” pesticides including triazinone herbicides (Velpar®) and organophosphate insecticides (Phosmet®) (Fig. 2.2).  In the case of burning, although this technology (Fig. 2.2) was effective at reducing selected weed, fungal and insect pressures, increasing challenges with regulations (permit requirements), oil costs (>$1,000/ha) and carbon dioxide emissions made this technology nonviable and subject to public criticism (Fig. 2.3). Similarly, although blanket applications of fertilizers and herbicides were effective in stimulating plant growth, the combination of stimulating weed pressure growth in areas with no blueberry cover (in the bare areas) and the repeated use of the herbicide Velpar® for over twenty years simulated weed tolerance and subsequent weed pressures and wild blueberry yield decline across wild blueberry production areas.

Figure 2.2 Life cycle analysis schematic depicting baseline technologies used in wild blueberry production prior to 2002, and the various stages in the production cycle where greenhouse gas emissions consumption and net energy transfer occurred.

Figure 2.3 Oil-fired blueberry burner that has been used as a baseline technology to prune fields and reduce pest pressures before the commencement of the next 2-year, production.

Figure 2.4 Life cycle analysis schematic the technologies being examined in the present phase of research activities (note these are shaded), and the various stages in the production cycle where greenhouse gas emissions consumption and net energy transfer occurred.

            Subsequently, the research activities that were initiated in 2004 placed emphasis on no longer treating wild fields as a uniform entity and attempting to develop quick methods of assessing vegetative pressures in blueberry fields (Fig. 2.4).  The remote sensing components that were completed in 2004 and 2005 clearly indicated that wild blueberries, weed pressures and bare areas in blueberry fields could be readily detected with a compact airborne spectroradiometer imagery (CASI) followed up with field level validation with a VIS/NIR spectroradiometer, visual assessments, and orthocorrection (Figure 2.5). However, these technologies were determined unlikely to be commercialized due to required weather conditions when data was being collected (no cloud cover or wind: only two days of these conditions were present during the required three phases of the growing season in 2004 and 2005), multiple arrays of required equipment (aircraft, CASI unit, field VIS/NIR spectroradiometer, high resolution GPS unit with base station, etc.), and most importantly, an incredible amount of time for processing and post processing  results. The results from research did clearly illustrate that it was possible to use spectral signatures to classify vegetation in blueberry fields, and this could subsequently be used to define the areas within a field that pesticides had to be applied depending on the vegetation classification (Fig. 2.5). 

            In addition to placing emphasis on vegetation classification, research has also focused on assessing soil moisture levels on a spatial basis, relaying this information in a wireless manner back to a central processing unit which could determine which areas within a field needed supplementary irrigation. Lead by Dr. J.P. Privé, the intelligent irrigation system is in the process of providing producers with a suitable means of applying water judiciously to wild blueberry fields.  With finite supplementary irrigation water sources, and irrigation systems often relying on diesel pumps, this system has the potential to provide blueberry producers with a suitable application technology to meet future demands.

Figure 2.5 Remote sensing analysis of a commercial wild blueberry field consisting of a red-green-blue digital color photograph (top left: 25 cm resolution), and infra-red image (top right 25 cm resolution). Analysis of CASI hyper spectral data provided for the classification of weed pressures (bottom left in yellow) and wild blueberries (bottom right in red) which were subsequently transformed into individual field “prescriptions” for herbicide applications (applied just to the yellow areas) and fungicide applications (applied just to the red areas).

         In 2002, the wild blueberry industry was facing significant pest management challenges resulting from (i) a reliance on several outdated pesticides including carbamates, photosynthetic inhibitors (triazinone) and organophosphates; (ii) herbicide tolerance and severe subsequent broadleaf and grass pressures, and (iii) leaf diseases including Septoria and rust that caused premature defoliation and severe yield reductions (Fig. 2.6).  To accommodate these challenges, considerable emphasis was placed on screening new pesticides that were more environmentally friendly, more specific in their mode of action, and more acceptable to Canadian and international end users with no associated residue issues in harvested and processed berries. 

Figure 2.6 Premature defoliation of blueberry stems in the vegetative (i.e., “sprout”) phase of production due to Septoria and rust fungal pathogens (left) and retention of foliage through the use of fungicide applications (right).  The retention of this foliage is critical for the floral bud formation process and subsequent yield potential which starts in midsummer and proceeds throughout the autumn.

         Therefore, the wild blueberry industry is presently in a situation where hyper spectral vegetation classification systems have been assessed, supplementary irrigation groundwater sources have been accessed, an intelligent irrigation system is in the process of being developed, and more environmentally friendly, efficacious and end-user acceptable pesticides are being screened and when feasible, brought into commercial production.  Significant gaps still remain that need to be explored including improved field sanitation technologies, plant and environment sensing technologies, and improved quality assessment and traceability provisions for harvested berries.

Figure 2.7  Life cycle analysis schematic including the wild blueberry production cycle, present wild blueberry research activities underway (in grey boxes) and proposed next phase of research activities (in the blue boxes) with emphasis on (i) field sanitation, and (ii) automated environment and plant sensing technologies.

         The proposed research project is incremental and provides the next phase of research and development activities pertinent to this initiative. Emphasis for the proposed research is being placed on the development of novel, pre-emptive and non-chemical technologies for pest management control; technologies to better assess environmental criteria pertinent to blueberry growth and development; and automated harvesting and food traceability techniques that when combined will reduce agrochemical usage, increase yields, reduce the cost of production, increase production efficiency, and improve food traceability and safety. These research components are crucial for the wild blueberry industry to maintain its image as a low agrochemical and energy input, minimally managed (“wild”), environmentally responsible, and high product quality sector, especially taking into account the global challenges posed by the highbush blueberry (intensively managed and rapidly expanding) and European bilberry (minimally managed and poorer quality) sectors.