Projects
UF Tea projects have been funded by FDACS Specialty Crop and USDA-SARE grants. See what we’ve been working on, what we have learned so far, and what we have planned for the future.
Establishing a Tea Industry in Florida: Cultivar and Disease Assessment
This project was funded by a 2015 FDACS Specialty Crop block grant (FDACS #022918). The project goals were to test some of the most readily available tea varieties in the southeastern US for performance under Florida growing conditions, to document any disease problems that occurred, and to determine which varieties may have better heat tolerance and disease resistance than others. As of the end of the grant period, ‘Big leaf’/ ‘Large leaf,’ ‘Fairhope,’ and ‘China’ had the best survival; ‘Fairhope,’ ‘Georgia,’ and ‘Big leaf’/ ‘Large leaf’ had the highest yields; and ‘Big leaf’/ ‘Large leaf’ and ‘Fairhope’ showed the greatest field resistance to anthracnose. These results cover only the first two years (establishment period) in the field; data collection on these plants is continuing, using donated and program funds to cover the costs of plot maintenance.
Publications:
Orrock, J. M., Rathinasabapathi, B., and Spakes Richter, B. 2019. Anthracnose in U.S. Tea: Pathogen Characterization and Susceptibility Among Six Tea Accessions. Plant Disease. 104:1055–1059. https://doi.org/10.1094/PDIS-07-19-1518-RE
Orrock, J. M., Richter, B. S., and Rathinasabapathi, B. 2021. Performance of Seven Tea Accessions in North-central Florida: Correlations between Potential Yield and Growth Parameters over 2 Years. HortTechnology. 31:1–7. https://doi.org/10.21273/HORTTECH04908-21
Establishing a Tea Industry in Florida: Tea Quality
Caffeine and phenolics are compounds in tea that are associated with tea quality. Research suggests that polyphenolic compounds in green tea are also excellent antioxidants and hence are health promoting. We are using phytochemical methods to measure the levels of health promoting polyphenolic compounds and caffeine in tea grown in Florida. We aim to identify varieties and growing conditions that best maximize the compounds of interest in tea leaves which are suitable for producing excellent quality tea. This project has been partially supported by the above FDACS Specialty Crop block grant.
Shade and Ground Cover Growing Systems for Tea Production in Florida
This project was funded by a 2018 USDA Southern SARE grant (SARE #LS18-297) to examine companion cover and shade crops for tea production, including impacts on tea growth and yield, weed suppression, soil nutrient cycling, and disease incidence. We established tea plots in cooperation with two local growers in Alachua and Marion counties, using three tea varieties (‘Large leaf,’ ‘Fairhope,’ and ‘Red leaf’), three ground cover treatments (weed barrier fabric, perennial peanut, and an annual crimson clover rotation), and two shade trees (initially, moringa and persimmon). While weed barrier fabric provided superior suppression of weed competition, and plants in this treatment had higher early yields (3 years after planting), weed barrier fabric did not improve plant survival and had a negative impact on soil nutrients and nutrient cycling microbial populations.
Moringa trees did not rebound sufficiently from frost events to provide shading during the early summer, and was replaced by everbearing mulberry, which grew well but required frequent pruning to keep low-hanging branches from interfering with tea maintenance and harvest. Persimmon had the best survival and value added (salable fruit), and good compatibility with the tea-growing system. We left unplanted tea rows in this system for future plantings to test the impacts of shade on tea plant establishment. Now that the persimmon trees are large enough to provide significant shade, plans are underway to embark on the next phase of this work.
Other Projects
Tea Genetics & Breeding
Historically, tea has been divided into two major types: China and Assam. China-type teas were first domesticated in China, have smaller leaves, are better adapted to full sun, and are generally used to make green teas. Assam-type teas were domesticated in India, have larger leaves, are shade-adapted, and are traditionally used to make black teas. These two original types have been crossed over the centuries, both intentionally and through natural hybridization, so that most modern cultivars have some mixture of the original distinctive traits. Most of the tea plants sold in the US are crosses of plants imported in the 18- and 1900s, and their progeny are not well characterized. We have been working to characterize the tea plants available for purchase in the southeastern US, to develop a breeding program for new varieties better adapted to our local growing conditions.
Tea Endophytes
Endophytes are microorganisms that live inside plant tissues without causing any obvious symptoms. Some may be helpful to the plant, by producing compounds that deter pests or pathogens, while others are just using the plant for shelter, and scavenging sugars in between the plant cells. We are currently examining fungal endophytes of tea in an effort to (1) identify the fungi that could be considered “normal residents” of tea in Florida, (2) determine whether any of these fungi may inhibit or out-compete foliar pathogens, like the ones that cause anthracnose disease, and (3) explore the role of tea plants as an asymptomatic carrier of fungi that may cause disease on other plants.
Tea Propagation
Tea can be quite challenging to produce. Seeds are only viable for a short time, and cuttings have variable success rates, depending on variety. Undergraduate researchers in our program are working on basic questions about vegetative propagation of US tea varieties, documenting success rates for cuttings among the available stocks, and fine-tuning procedures for tissue culture propagation.