Advisers: David Eissenstat and Rich Marini
Ph.D candidate in Horticulture, 2013 to present
M.S., Horticulture, The Pennsylvania State University, 2013
B.S., Plant Genetics and Plant Breeding, Purdue University, 2010
Well-managed apple trees may allocate 70-80% of seasonal photosynthates to fruiting each year. With limited carbohydrates available to roots, how are these trees able to sustain such high demand of water and nutrients for fruit production? Nutrient foraging strategies of fine roots and mycorrhizal fungi in response to shifts in aboveground carbohydrate demand may provide insight into this efficient fruit production. The objective of my research is to determine how fine roots and mycorrhizal fungi shift foraging strategies in nutrient-rich patches in response to aboveground carbohydrate demand in cropped and non-cropped trees.
In addition, mycorrhizal fungi are associated with improved nutrient uptake, especially for phosphorus, and possibly enhanced root defenses against herbivores and pathogens. Yet, less than 50% of fine roots in apple are colonized by arbuscular mycorrhizal fungi in cropped trees. Cropping may limit carbohydrates available for mycorrhizal colonization which in turn may affect root defenses against soil-borne fungal pathogens. Therefore, I am also exploring the potentially protective role of mycorrhizal fungi against putative pathogens at the individual root level.
This work has significance beyond fruit production. As we strive to understand ecosystem responses to elevated CO2 and incorporate accurate representations of belowground processes in ecosystem models, root and fungal dynamics are largely undefined and poorly represented. Uncovering linkages between carbohydrate availability belowground and root and fungal nutrient foraging patterns will improve our understanding and predictability of these complex processes.
Awards and Honors
2014 Tag Along Award, College of Agriculture, The Pennsylvania State University, $1500
2013 American Pomological Society UP Hedrick Award, $300
Lavely E., R. Marini, R. Crassweller, and D. Eissenstat. Stored carbohydrates as a factor in thinning efficacy based on the carbon balance model. State Horticulture Association of Pennsylvania (SHAP). 2014. $10,053.
Lavely E.K., R.P. Marini, B.K. Gugino, and K. Demchak. The role of Rhizoctonia fragariae strains and environmental interactions in black root rot development. North American Strawberry Growers Association. 2012. $7,000.
Marini R., B. Gugino, K. Demchak, and E. Lavely. The role of Rhizoctonia fragariae strains and environmental interactions in black root rot development. Pennsylvania Vegetable Growers Association. 2012. $3,000.
Marini R., B. Gugino, K. Demchak, and E. Lavely. Understanding strawberry black root rot in Pennsylvania. Pennsylvania Vegetable Growers Association. 2011. $5,400.
Lavely, E.K. 2013. Effects of abiotic factors and Rhizoctonia fragariae on strawberry growth and development of black root rot. Penn State Univ., University Park, Ms Thesis.
Lavely, E.K., B.K. Gugino, K. Demchak, and R.P. Marini. 2013. The effect of Rhizoctonia fragariae, soil type, compost, and mechanical root injury on strawberry growth. Amer. Pomol. Soc. 67(4):228-236.