Kari Dunfield & Robert Hanner & Steven Newmaster
Kari Dunfield & Robert Hanner & Steven Newmaster
Ontario Ministry of Agriculture and Rural Affairs (OMAFRA)
Agriculture has been identified as a significant contributor toward phosphorous (P) loading in Lake Erie, and has received considerable attention for this role. Soil conservation efforts such as no-till have delivered reductions in particulate P loading; however, these efforts have been offset by an increase in dissolved P, which have been partly attributed to the broadcasting of fertilizer on soil surfaces which do not receive incorporation and are susceptible for loss through surface water. Future conservation strategies for long term sustainability will need to address both issues – reduction in erosion (reduces particulate P loss) with simultaneous incorporation of fertilizer into the soil (reduces dissolved P loss). Strip tillage is one system which could potentially address both reduced tillage and sub-surface placement of larger amounts of fertilizer. Strip tillage has been investigated and promoted as a conservation tillage system for nearly 20 years in Ontario, and is now seeing considerable momentum and uptake in the farm community. More research is required to evaluate the ability of strip tillage to replace surface applications of P and potassium (potash, K) fertilizer, and further refine management recommendations for current corn hybrids and strip tillage technology for those who are converting to it.
This project will investigate the response of P and K fertility and placement in a strip tillage system relative to broadcast and conventional tillage practices by conducting trials in Perth, Wellington, Brant and Oxford counties. Four or five trials will be conducted each year to investigate the ability of strip tillage and fertility placement systems to compete competitively with broadcast fertility and conventional tillage systems. Trials will be conducted with co-operators who are currently under conventional tillage systems, and for fertilizer response potential will be placed on locations with low P or K fertility. Treatments will investigate a variety of tillage and fertilizer placements methods to answer the above objectives over three growing seasons.
University of Guelph
BASF, Bayer Crop Science Inc., Monsanto Inc., Syngenta Inc., Valent Canada Inc.
The overreliance on a single weed management strategy or a simplified crop rotation may have short-term advantages such as simplicity and possible short-term profit maximization, but may have long-term detrimental effects due to the evolution of herbicide-resistant biotypes. Herbicides have been a very cost-effective option for weed management in field crops for over 70 years. But the overreliance on herbicides has resulted in the evolution herbicide-resistant biotypes, sometimes multiple-resistant biotypes as is the case with waterhemp (Amaranthus tuberculatus var. rudis) in Ontario. Studies conducted on Ontario farms showed waterhemp pressure can result in up to 48% yield loss in corn and up to 73% yield loss in soybean. Glyphosate-resistant (GR) waterhemp has been confirmed in 40 fields in Essex, Chatham-Kent and Lambton Counties. To make matters worse for Ontario farmers, 61% of seed samples collected had 3-way multiple resistance to Group 2 (Pursuit), Group 5 (Atrazine) and Group 9 (Roundup) herbicides. This dramatically reduces the herbicide options for controlling this competitive weed. This small-seeded, summer annual, broadleaf weed has an extended emergence pattern, has high genetic diversity, is a prolific seed producer, is very competitive and has the potential to spread rapidly throughout Ontario if not properly controlled.
This project aims to study many of the principles of Integrated Weed Management (IWM) to deplete waterhemp seed in the seedbank and to develop a more sustainable approach to weed management using multiple weed management tactics. The diverse crop rotation will include crops with different seeding and harvesting times, crops with different row widths and seeding densities, the inclusion of cover crops, and the use of multiple herbicide modes-of-action. These integrated strategies are expected to limit the selection of herbicide-resistant waterhemp, reduce seed return to the seedbank and reduce its movement from field-to-field in Ontario. Waterhemp seed density in the seedbank will be determined prior to initiating the experiment and after the 3rd year of the study (after one cycle of a 3-year crop rotation). Corn, soybean and wheat will be grown in a 3-year rotation, with a cover crop seeded after winter wheat harvest. The most efficacious herbicides will be used in each crop. As a result of this research, Ontario grain farmers will have data from local studies on the effectiveness of many of the principles of IWM that could lead to the development of long-term, sustainable weed management strategies for control of waterhemp in corn, soybean and wheat rotation.
Xueming Yang & Dan Reynolds
Harrow Research and Development Centre, Agriculture and Agri-Food Canada (AAFC)
Soil and water quality in southwestern Ontario are important to maintain in order to achieve improvements in field-crop yields, reduce sediment in streams and lakes, and limit appearance of dead zones and algal blooms in the lower Great Lakes, especially Lakes St. Clair, Erie, and Ontario. Water quality is of national and international importance because the Great Lakes represents about 20% of the world’s fresh water reserve, which is shared and relied upon by more than 40 million Canadians and Americans for drinking water, field-crop irrigation, commercial and sport fishing, and general recreation. Agriculture has an acknowledged role in the soil and water quality of the Great Lakes watershed. Farmers recognize that intensive crop production systems can lead to the degradation of the soil by decreasing soil structure, permeability, and soil organic carbon content. Cover crops may play an important role in maintaining soil health and influence carbon and nitrogen stores. Although there are many anticipated agronomic, economic, and environmental benefits to using cover crops, they can be difficult to implement in crop rotations with long-season crops such as corn and soybean as there are not sufficient growing degree days left in the fall for successful establishment when the cover crop is planted after harvest. Preliminary work suggests that seeding certain cover crops (e.g. hairy vetch, red clover, crimson clover) after winter wheat harvest can significantly reduce losses of nitrogen from agricultural lands by: 1) scavenging “left-over” nutrient after harvest from the crop root zone and storing the nutrient; and 2) by increasing the soil’s ability to store air and water, sequester organic carbon, and retain and recycle nutrients within the crop root zone.
The anticipated outcome of this research project includes recommendations for better selection and management of cover crops to improve the economic and environmental performance of corn-soybean-winter wheat rotations in southwestern Ontario. This research project will address gaps in our knowledge regarding: i) which cover crops are best suited for planting into wheat stubble or standing corn (i.e. intercropping); ii) the best method for termination and incorporation of the cover crop; iii) which cover crops are most effective for scavenging “left-over” nutrient after harvest, increasing soil organic matter, and improving soil physical quality; and iv) how much “nitrogen credit” cover crops provide to corn on southwestern Ontario’s medium and fine textured soils (e.g. Brookston clay loam) in the lower Great Lakes watershed.
Art Schaafsma & Jocelyn Smith
University of Guelph
OMAFRA – UofG Research Program; CFIA; Mitacs; DuPont; Syngenta; Dow AgroSciences
First identified in Ontario in 2008, western bean cutworm has become a significant economic pest of corn in Ontario. Western bean cutworm (WBC) continues to plague Ontario corn producers with losses mainly in grain quality due to insect damage-related moulds resulting in mycotoxin contamination. Fusarium graminearum infection which occurs frequently in Ontario results in increased contamination of grain with mycotoxins that have serious negative effects on the health of livestock and human consumers. The mycotoxin deoxynivalenol (DON), also known as vomitoxin or VOM, is probably the most important quality factor in trade of Ontario corn affecting both the livestock and ethanol industries. The distribution of WBC has significantly expanded from its native range in the western U.S. across the Midwest Corn Belt over the last few decades and recently into eastern Canada. There are three problems: one, the current published action threshold is yield-based and we have learned that it is not conservative enough because of the importance of mycotoxins; second, the transgenic solution we had hoped for in Cry1F has failed; and third, growers are depending mainly on one insecticide product (i.e. Coragen) to manage this pest.
The overall goal of this project is to develop a more reliable decision threshold to minimize insecticide use, the introduction of alternative active ingredients, and an insecticide resistance management (IRM) plan. A further benefit is that the seed industry will be introducing competitive hybrids carrying a new transgenic Bt protein (Vip3A) which our lab and field tests have shown to be highly effective against WBC. Again, reliance on this strategy alone will inevitably lead to the evolution of resistance. We propose to include the introduction of Vip3A in an IRM plan with the overall strategy of simultaneously extending the useful life of both the insecticides and the Vip3A trait. The overall benefit of this project will be development of a sustainable plan that will provide corn producers with a long term strategy for WBC management.
Ian Scott & Sangeeta Dhaubhadel
Agriculture and Agri-Food Canada
Two important soybean pests are the soybean aphid (Aphis glycines) and the two-spotted spider mite (Tetranychus urticae). When populations of these two herbivores are high, there can be a severe reduction in soybean yield. The current strategy for aphid management involves monitoring and reacting by applying insecticides to reduce the aphid pressure. Spider mites are an emerging pest due to the increasing incidence of warmer, drier weather conditions in Ontario. Insecticides are applied to control high populations of aphids and mites; however, the over-use of insecticides may cause mite populations to flare up by reducing native beneficial enemies (lady bird beetles and predatory mites). Isoflavonoids are legume-specific plant natural products abundant in soybean. Their production is induced by herbivores, including hemipterans (e.g. stink bugs and aphids) and lepidopterans (e.g. armyworms and leaf worms), and are characterized by feeding inhibitory activity and growth inhibitory activity on herbivorous insects. Reducing the number of insecticide applications or delaying applications until later in the growing season by slowing aphid and mite population growth is the goal of developing more resistant soybean cultivars to these pests.
This project examines the levels of isoflavonoids in leaves of several Ontario grown soybean cultivars to determine which compounds are most active and which cultivars are important for managing aphid and mite populations to provide an additional tool for soybean IPM. This project will screen resistance of several Ontario soybean cultivars from different maturity groups to the two pests by measuring plant damage as well as growth and reproduction of aphids and mites. Chromatographic techniques will be used for analysis of isoflavonoids in the resistant cultivars. Statistics will be used to correlate the biological and chemical data for isoflavonoids identified in the cultivars and the corresponding pest damage ratings. The findings can be used by growers to select cultivars with increased herbivore resistance when early season predictions indicate conditions preferable for aphid and/or mite infestations. The evidence will also provide direction for breeding or metabolic engineering of specific isoflavonoids into currently registered cultivars to improve their resistance.
A. R. McElroy
PhytoGene Resources Inc.
Oat is a valuable rotation crop in Ontario and there are good markets for high-quality grain for both feed and milling. However, low yields, compared to some other cereals, and low test weight (‘light oats’) diminish its popularity. Both problems relate to grain fill. PhytoGene Resources Inc. has determined that the number of kernels per panicle is the major yield determinant, and that the proportion of unfilled kernels – a phenomenon not related to stress during the grain filling period – affects yield, and particularly average seed mass and test weight. Both parameters have been shown to be heritable. Evaluating these traits is laborious and expensive, since individual panicles must be threshed and the seed cleaned prior to counting the filled and unfilled kernels. The use of molecular markers would increase the efficiency of screening for these two traits. An in silico array chip has been developed for oat and contains approximately 6,000 molecular markers called single nucleotide polymorphisms (SNPs). This ‘6K chip’ may contain SNPs associated with quantitative trait loci (QTLs) that are related to kernel number per panicle and the percent of unfilled kernels.
The project will test whether the ‘6K Chip’ can be used to develop molecular markers to enhance selection for kernel development in oat. Fifty elite oat lines which have been tested with the ‘6K Chip’ will be grown in replicated plots in Cumberland, ON. Panicles with uniform heading date will be tagged in each plot; these will be hand-harvested and evaluated for filled and unfilled kernels, as well as number of kernels per panicle. The remainder of each plot will be bulk harvested with a plot combine to generate yield data. Then statistical analysis will be used to identify associations between the SNPs and the observed traits (kernel number per panicle, plot yield and unfilled kernels).
David Guttman & Gopal Subramaniam
University of Toronto / Agriculture and Agri-Food Canada
Agriculture and Agri-Food Canada (Microbiome & Metatranscriptome grant); Compute Canada Resource Allocation Competition (RAC)
Fusarium head blight (FHB) is a devastating global disease of small grain cereals that has been called “the worst plant disease to hit the US since the rust epidemics in the 1950s”. The disease is caused by the fungus Fusarium graminearum, which overwinters in crop debris and infects grain heads under favorable environmental conditions. FHB poses a double threat. First, it can significantly reduce both yield and seed germination by discoloring and shriveling the grain kernels. Second, the pathogen produces mycotoxins that contaminate grains during infection, and which are a very direct health risk to humans and domesticated animals. The severity of FHB infection depends on the cereal variety, amount of fungal inoculum and favorable weather conditions. The most effective control strategies have relied on the use of resistant varieties and fungicides; however, these control measures are not always effective, resulting in massive crop losses or contaminated grain. Consequently, there is very strong interest in the identification and development of novel biocontrol agents that can assist in the fight against this disease.
The goal of the project is to understand the contribution of microbial communities to the health of wheat plants. During the study, microbial communities called microbiomes will be assessed to determine how they differ among cultivars with different levels of FHB susceptibility, and determine how the microbiomes respond to F. graminearum infections and the development of FHB disease. This study will provide the first look at the microbiological changes that occur during the FHB development. It will assess the impact of both host (wheat) and pathogen genetic variability on FHB disease development. Understanding the wheat head microbiome and the dynamics of this community during FHB disease development has the potential to reveal new pathogen antagonists or growth promoting microbes, and thereby facilitate the identification of novel biocontrol agents.
University of Guelph
Corn is the largest single recipient of nitrogen (N) fertilizers applied to agricultural crops, yet less than half of the N fertilizer applied to corn is recovered in grain. Greater than 50% of fertilizer N remains at risk of exiting the agro-ecosystem before crop uptake. Low fertilizer nitrogen use efficiency (NUE) is an economic inefficiency with profound implications for global N cycling and N pollution. Optimal fertilizer N rates in corn varies across years and across fields, making it difficult to predict the correct rate. The primary reason for this variation in optimum N rates is because soil moisture affects both natural soil N supply and corn N demand. Existing N recommendation systems have had limited success in predicting this variation, because the effect of moisture availability on corn N demand is often ignored. The effect moisture on corn N demand remains difficult to address, since this variation occurs after traditional side-dress timing, usually within the first two weeks of June.
The objective of this proposal is to develop a corn N decision support system (DSS) and on-farm protocol in collaboration with stakeholders. The corn N DSS will build on the “OMAFRA General Recommended Nitrogen Rates for Corn: Corn N Calculator” and will be designed to consider the effects of moisture on both soil N supply and corn N demand. Field trials on new corn hybrids will test how soil moisture affects corn N requirements at different corn stages and uptake at later stages of growth. New N datasets produced from these field trials will be added to the current Corn N Calculator and will be used to determine if delta-yield will predict Maximum Economic Rate of Nitrogen (MERN). This delta-yield approach simplifies MERN calculations, and if proven, would allow farmers to more easily measure the variability of yield response to N across their fields. The validation of a corn N DSS requires substantial amounts of data. Historically researchers have assumed this task, but with the emergence of precision agriculture/big data capabilities, farmers can now also be directly involved with data generation. A protocol will be developed so that farmers can actively participate in data generation for on-farm validation.