College of Agriculture & Natural Resources Department of Horticulture

Education

• PhD, Horticultural Science, Purdue University, West Lafayette, IN (2017)
• Mini MBA, Krannert School of Management, Purdue University, West Lafayette, IN (2016)
• MSc, Agricultural Science, Assiut University, Egypt (2006)
• Diploma, Horticulture Genetics & Biotechnology, Mediterranean Agronomic Institute of Chania, Greece (2003)
• BSc, Agricultural Science, Assiut University, Egypt (2000)

Research Overview

My research focuses on floral initiation, plant growth regulators, and nutrient management to optimize flowering, fruit set, and stress resilience in apples and cherries. I study how root–rhizosphere architecture, resource allocation, and pruning strategies interact with hormonal signaling to influence alternate bearing, bloom regulation, and tree productivity, while developing climate-smart, organic-compatible, and data-driven orchard practices. A major initiative integrates petiole sap analysis with machine learning to enable real-time precision nutrient management in Michigan orchards. Through molecular, physiological, and applied field research with growers, my program aims to enhance fruit quality, nutrient efficiency, and orchard resilience, making Michigan apples and cherries more competitive in international markets.

Recent Research Articles

Griffith, C., Elsysy, M.A., & Einhorn, T. (2025). Successive Early-season Abscisic Acid and Auxin Applications Consistently Mitigate Bitter Pit of ‘Honeycrisp’ Apples without Increasing Peel Calcium Concentration. Journal of the American Society for Horticultural Science, 150(5), 249–261.

Elsysy, M.A., Aziz Ibrahimi, & Einhorn, T. (2025). Wind pollination of apple flowers under insect exclusion nets challenges the insect-dependent pollination model of modern apple plantations. Plants, 14(8), 1196. (Corresponding Author)

Einhorn, T., Ruwersma, D., Elsysy, M.A., & Hubbard, D. (2025). GA4 + 7 Rate and Timing Interact to Suppress Return Bloom of Young “Honeycrisp” Apple Trees and Improve Tree Growth. American Journal of Plant Sciences, 16, 275–286.

Einhorn, T.C., & Elsysy, M.A. (2024). Stub length of renewed apple limbs interacts with cultivar and affects the number and quality of replacement limbs. Scientia Horticulturae, 338, 113719.

Morsi, A.H., Massa, G.D., Morrow, R.C., Wheeler, R.M., Elsysy, M.A., & Mitchell, C.A. (2024). Leaf yield and mineral content of mizuna in response to cut-and-come-again harvest, substrate particle size, and fertilizer formulation in a simulated spaceflight environment. Life Sciences in Space Research, 40, 106–114.

Elsysy, M.A., & Hirst, P.M. (2023). Flowering in ‘Honeycrisp’ Apple Shows That Spurs Are Semiautonomous Organs. Journal of the American Society for Horticultural Science, 148(3).

Elsysy, M.A., & Einhorn, T.C. (2022). Air-Pruning Containers Modify Root and Scion Growth and Alter Resource Allocation of Bench-Grafted Apple Plants. Horticulturae, 8(9), 797.

Germani, M.A., Elsysy, M.A., Toselli, M., et al. (2022). Ethylene emission and abscission of immature ‘Montmorency’ sour cherry fruitlets vary with ethephon concentration, phenology stage, and ambient temperatures following application. Plant Growth Regulation, 98, 141–153.

Elsysy, M.A., & Einhorn, T.C. (2022). Enclosure of apple canopies with insect exclusion, anti-hail nets during early bloom stages reduces fruit set and seed content of ‘Honeycrisp’, ‘SweeTango’, and ‘Fuji’ but does not negatively affect fruit size. Acta Horticulturae, 1346, 175–182.

Hillmann, L.A., Elsysy, M.A., Rothwell, N., Blanke, M., & Einhorn, T.C. (2022). A Growing Degree Hour model to explain hardiness loss of ‘Montmorency’ sour cherry floral buds during spring development. Acta Horticulturae, 1346, 139–144.

Hillmann, L., Elsysy, M.A., Goeckeritz, C., et al. (2021). Preanthesis changes in freeze resistance, relative water content, and ovary growth preempt bud phenology and signify dormancy release of sour cherry floral buds. Planta, 254, 74.

Elsysy, M.A., Hubbard, A., & Einhorn, T.C. (2020). Postbloom thinning of ‘Bartlett’ pear. HortScience, 14629.

Elsysy, M.A., & Einhorn, T.C. (2019). Air root pruning containers alter root architecture and increase canopy and root growth of apple trees compared to field-grown liners. Acta Horticulturae, 1281, 251–256.

Elsysy, M.A., & Hirst, P.M. (2019). Molecular Basis of Flowering Inhibition in apples caused by defoliation and gibberellins. Journal of the American Society for Horticultural Science, 144(6).

Elsysy, M.A., Serra, S., Schwallier, P., Musacchi, S., & Einhorn, T.C. (2019). Net enclosure of ‘Honeycrisp’ and ‘Gala’ apple trees at different bloom stages affects fruit set and alters seed production. Journal of Agronomy, MDPI, 9, 478.

Elsysy, M.A., & Hirst, P.M. (2019). Effect of fruiting and biennial bearing potential on spur quality and leaf gas exchange in apple. Journal of the American Society for Horticultural Sciences, 144(1).

Elsysy, M.A., & Hirst, P.M. (2017). The role of spur leaves, bourse leaves, and fruit on local flower formation in apple: an approach to understanding biennial bearing. HortScience, 52(9).

Extension Publications

Organic Apple Orchard Tour at Third Leaf Farms – Topp Partner Event

SARE Project: A Sustainable, Non-Chemical Thinning Method for Midwest Apple Producers

Netting on Fruit Trees Curbs Thinning Needs

NY Netting Study PDF

Effect of Net Enclosure on Honeycrisp and Gala Fruit Set and Seed Production

Controlling Crop Load with Nothing but Nets

Extension Presentations

Elsysy, M. (2025). Application of Whole-Tree Netting Systems Reduce Pollination and Fertilization, Eliminate Thinning, and Facilitate Crop Protection of Midwestern Apple Orchards. Great Lakes Fruit Workers Conference, Nov 17–19.

Elsysy, M. (2025). Growing Fruit. National Garden Clubs (NGC), Gardening School, Michigan.

Elsysy, M.*, Aspinall, R., & Einhorn, T. A Sustainable, Non-Chemical Thinning Method for US Midwestern Apple Producers: Novel Use of Anti-Hail, Insect-Exclusion Netting. Great Lakes Expo.

Einhorn, T., & Elsysy, M.* The number, length and quality of new apple replacement shoots after renewal pruning depends on the stub length and cultivar. Great Lakes Expo.

Einhorn, T., Elsysy, M.*, Lang, G., Rothwell, N., Ruwersma, D., Powers, K., & Byler, G. (2022). Performance of New Apple and Pear Rootstocks in Trials Across Michigan. Great Lakes Expo.

Elsysy, M.* Using nets for crop load management. Michigan Pomesters Ridgefest Field Day, Clarksville Research Center.

Einhorn, T., & Elsysy, M.* Insect exclusion, anti-hail nets reduce fruit set and thinning needs of apples. Great Lakes Expo.

Einhorn, T., & Elsysy, M.* Multi-Year Study on the Effect of Excluding Netting on Apple Fruit Set and Fruit Quality Attributes in Michigan. Great Lakes Expo.

Einhorn, T., & Elsysy, M.* Ethephon Applications Between Anthesis and Petal Fall Increase Ethylene Production Rate and Fruitlet Abscission of ‘Montmorency’ Tart Cherries in Combination with High Temperature. Great Lakes Expo.

Einhorn, T., & Elsysy, M.* Air Root Pruning Containers Alter Root Architecture and Increase Canopy and Root Growth of Apple Trees Compared to Field Grown Liners. Great Lakes Expo.

Elsysy, M.A.*, & Hirst, P.M. Achieving Consistent Flowering with Honeycrisp. Indiana Hort. Congress, Indianapolis, IN.

Elsysy, M.A.*, & Hirst, P.M. Winter Kill of Peach Flowers. Grower’s Meeting, Martinsville, IN.