Dr. Hao Xu

Research Scientist

Dr. Xu leads the tree fruit physiology program at Summerland Research and Development Centre. Her team aim to elucidate how fruit yield, fruit quality and tree resilience of apple and sweet cherry respond to horticultural managements and environmental stresses. 

Current research and/or projects

Dr. Xu's current research projects investigate the impacts of horticultural managements on reducing biotic and abiotic stress pressure, enhancing plant resilience, stabilizing yield, and improving fruit quality, in apple and sweet cherry. The horticultural approaches of focus are adjusting leaf-fruit ratio by pruning and crop load management, scheduling irrigation based on plant needs, as well as selecting suitable rootstocks for specific cultivars and micro-environments. On the fundamental level, the research team tries to elucidate how photosynthetic source-sink relations and rootstock resource use efficiency influence floral bud quality, fruit dry matter accumulation and carbohydrate allocation within the tree crops. The knowledge generated can facilitate decision making on how to maintain tree canopy, how to manage crop load, and how to select the most suitable rootstock-scion combination, for a more sustainable future of tree fruit production.


Research and/or project statements

A list of her key publications in the field of plant physiology

1. H Xu, JJ Zwiazek. 2020. Fungal aquaporins in ectomycorrhizal root water transport. Frontiers in Plant Science 11: 302.

2. P Zhang, Z Cui, H Xu, et al. 2020. Thirst or Malnutrition: The impacts of invasive insect Agrilus mali on the physiological status of wild apple trees. Forests 11: 440.

3. X Tan, H Xu, S Khan, et al. 2018. Plant water transport and aquaporins in oxygen-deprived environments. Journal of Plant Physiology 227: 20-30.

4. JJ Zwiazek, H Xu, X Tan, et al. 2017. Significance of oxygen transport through aquaporins. Scientific Reports 7: 1-11.

5. H Xu, M Kemppainen, W El Kayal, et al. 2015. Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings. New Phytologist 205: 757-770.

6. A Navarro‐RóDenas, H Xu, M Kemppainen, et al. 2015. Laccaria bicolor aquaporin LbAQP1 is required for Hartig net development in trembling aspen (Populus tremuloides). Plant, Cell & Environment 38: 2475-2486.

7. H Xu, JEK Cooke, JJ Zwiazek. 2013. Phylogenetic analysis of fungal aquaporins provides insight into their possible role in water transport of mycorrhizal associations. Botany 91: 495-504.

8. H Xu, Y Li, G Xu, T Zou. 2007. Ecophysiological response and morphological adjustment of two Central Asian desert shrubs towards variation in summer precipitation. Plant, Cell & Environment 30: 399-409.

9. H Xu, Y Li. 2006. Water-use strategy of three central Asian desert shrubs and their responses to rain pulse events. Plant and Soil 285: 5-17.

10. Y Li, H Xu, S Cohen. 2005. Long‐term hydraulic acclimation to soil texture and radiation load in cotton. Plant, Cell & Environment 28: 492-499.

Professional activities / interests

Besides her currently ongoing research in tree fruit production physiology, Dr. Xu looks into opportunities for the use of biological ingredients such as mycorrhiza and plant-based fertilizers in horticulture of woody perennials. She also remains strong interest in the roles of aquaporins in plant-water relations. 

Education and awards

Ph.D. in Forest Biology and Management, University of Alberta

Ph.D. in Plant Ecology, Chinese Academy of Sciences

Key publications

  1. MacDonald JL, Hannam KD, Xu H. 2022. Signs and symptoms of sudden apple decline in British Columbia: Impacts on tree physiology, and the potential role of environmental stressors. Canadian Phytopathological Society Annual Meeting. Virtual. 4 July 2022. Oral Presentation

    2022 - View publication details

  2. Xu H, MacDonald JL, Singh A, Pagliocchini C, Ediger D. 2022. Apple
    rootstock vigor and production: effects of rootstock on Honeycrisp.
    Agriculture and Agri-Food Canada, Summerland, BC, Canada. 11p.

    2022 - View publication details

  3. Proper balanced nutrition is important in all crops; however, knowing what the right nutrient needed at the right time for the right reasons with the right product can be very different between commodities, orchards, and seasons. There are several different sampling methods that can be utilized to assess the nutrient status of a block and help aid in nutrient management decisions. The main assessment methods are leaf, fruitlet, and soil analysis. There are some other techniques, such as sap analysis, that are being tested and may be more available in the future.

    2021 - View publication details

  4. Autio, W, Robinson, T, Blatt, S, Cochran, D, Francescato, P, Hoover, E, Kushad, M, Lang, G, Lordan, J, Miller, D, Minas, I, Parra Quezada, R, Stasiak, M and Xu, H. 2020. Budagovsky, Geneva, Pillnitz and Malling apple rootstocks affect ‘Honeycrisp’ performance over eight years in the 2010 NC-140 ‘Honeycrisp’ apple rootstock trial. Journal of the American Pomological Society 74: 182-195.

    2020 - View publication details

  5. MacDonald JL, Forge T, Hannam K, Judd G, Moffat C, O'Gorman D, Sanfacon H, Xu H. 2020. 'Apple Decline' in the Okanagan Valley. Summerland Research and Development Centre via Instagram and Facebook.

    2020 - View publication details

  6. Tan, X., Xu, H., Khan, S., Equiza, M.A., Lee, S.H., Vaziriyeganeh, M., Zwiazek, J.J. (2018). Plant water transport and aquaporins in oxygen-deprived environments. Journal of Plant Physiology, [online] 227 20-30. http://dx.doi.org/10.1016/j.jplph.2018.05.003

    2018 - View publication details

Research facility

4200 Highway #97
Summerland, BC V0H 1Z0


Dr. Xu is a professional agrologist in British Columbia Institute of Agrologists. 



Other languages

Chinese, Mandarin