Taylor Wallace began her post-secondary education at Mohawk College in the Environmental Technician Program. Nearing the end of her program at Mohawk, Taylor desired to expand her post-secondary education even further, and enrolled in the Environmental Science program at the University of Guelph (UofG). She recounts that very soon after starting at the UofG she had a growing desire for more hard science and switched to the toxicology stream. Taylor graduated in 2012 with a Bachelor of Science degree in Environmental Toxicology.
During her undergraduate tenure, Taylor worked for the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Her supervisors were Mike Celletti, Pathologist for Horticulural Plants, and Denise Beaton, Crop Protection Program Lead. The project Taylor was involved with focused on plant parasitic nematode (PPN) populations in garlic – this is how she came to first learn about nematodes, and also meet her future faculty advisor, Dr. Katerina S. Jordan, Associate Professor, Department of Plant Agriculture at the UofG.
Taylor explains that nematodes are worm-like aquatic organisms that are ubiquitous on planet earth. Of the 25,000 species currently identified, only fifteen percent are capable of parasitizing plants. PPN parasitize plant tissues causing damage to foliar tissues and roots. Root pathogenic PPN, the most common, cause inhibition of nutrient and water uptake due to their feeding. A reduction in effective plant root mass will in time create stress on the plant and inhibit growth. If the populations of PPN are very high, and neither growth conditions are improved, nor are control measures applied, death of the plant may result.
Much like vegetable crops, there are not many options to control PPN in turfgrass systems in Canada. Taylor notes that there are some potential options for chemical controls that may soon be in the registration pipeline, but explains that at this point in time, the main methods of control are cultural and related to improving the overall growing environment. It is well known that mowing turf at a higher height of cut will help to stimulate and improve root growth. In addition, improved lighting conditions and air movement from tree pruning can also contribute to a stronger turf that will not be as susceptible to root damage from PPN.
Taylor’s M.Sc. research project was entitled “Plant Parasitic Nematodes in Managed Turfgrass Systems in Canada” and had three main objectives.
a) The best extraction method for PPN
b) The population distribution of PPN on golf greens in Canada
c) How PPN populations are affected by time of year and age of the golf green
Taylor describes the active PPN research in the turf lab as being “Dr. Jordan’s baby.” Dr. Jordan’s Ph.D. research project involved an extensive survey and nematode sampling of numerous golf courses in the Coastal Atlantic United States; the project examined populations of PPN in relation weather patterns, age of the turf site, and soil properties. In addition, Dr. Jordan attempted to characterize the microbial activity in the soil in hopes of determining the potential for biological control of these pests.
In terms of addressing her objectives, Taylor examined two widely accepted methods of nematode extraction: The passive Baermann-Pan method, and the active centrifugal method. Taylor identified from her research that the active method of nematode extraction allowed her to extract significantly more PPN from the soil samples. The passive method was determined to be much less accurate for counting sedentary nematodes, many of which are found parasitizing turfgrass plants.
Some very interesting results from Taylor’s large spectrum sampling of golf courses across Canada included the discovery that spiral nematodes were highest in concentration in the coastal provinces, with up to over 11,000 nematodes per 100 cubic centimetre (cc) of soil. On putting green turf, the threshold for spiral PPN to cause damage is 1500 individuals per 100cc of soil. In Ontario specifically, the most prevalent genus identified was the stunt nematode.
Summarizing the population findings, Taylor remarks that “the result of the project was populations that were sometimes over threshold throughout Canada, but it is likely that they are not causing primary damage at most sites like we would see in the southern US where they are a real problem. It is more likely PPN are causing reductions in compensation by the plant and making them more susceptible to other stresses and pathogens. It is a pest that we should be concerned with in Ontario, but at this time we only have cultural practices to reduce plant stress with few options for reducing established populations.” Future research will continue to investigate potential options for nematode control in Ontario.
In testing the third research objective of the study, Taylor identified that greens over the age of 20 years had higher PPN counts than those that were younger than 20 years of age. PPN populations also increased as the age of the green increased up to 80 years of age. Climatic variation also seemed to have an effect on PPN populations. Taylor notes that “changing climates and fluctuating winters seem to be good for reducing nematode populations.” Taylor also hypothesizes that the observed population reduction has to do with dormancy interruption, and that long cold winters seem to preserve populations – this could be promising news for the future, but as Taylor notes “I am sure they will find a way to adapt to the fluctuating conditions.”
On campus Taylor has won the Dean’s scholarship for academic achievement, and also had great success at the Crop Science Society of America meeting in 2014 where she presented a poster entitled “Plant Parasitic Nematodes in Managed Turfgrass Systems in Canada.” Taylor’s poster won the Turfgrass Industry award (Division C-05, Turfgrass Science).
In addition, Taylor found the department most welcoming: “The Plant Agriculture department is very warm and welcoming and is very much like a family. I have definitely experienced this within the turf group as well everybody is so willing to help and willing to share knowledge and information readily, which makes it a positive learning experience. I always felt like I had the assistance that I needed. It has been interesting to learn about turf because I honestly hadn’t even been on a golf course before starting my Masters.”
As for Dr. Jordan and Dr. Lyons, our resident turfgrass faculty, Taylor remarks that “they are definitely the most fun professors I have met. I don’t feel like they were my supervisors or my committee members, I feel like we are friends. They make it a very enjoyable environment. It is fun to be part of the lab and part of the ‘family’.”
Taylor successfully defended her thesis in January, 2016, and continues her career in the Department of Plant Agriculture. She is working alongside Dr. Jordan as a research associate in the turf lab!
Project funding generously provided by the Ontario Turfgrass Resarch Foundation (OTRF)
Article authored and published by John R. Watson, Guelph Turfgrass Institute Communications Assistant
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