Ferrarezi Lab Current Projects

 Sungeun Lim (PhD student at Purdue University) is evaluating the effect of light quality on ornamental cutting propagation. Acclimating cuttings indoors for greenhouse finishing offers opportunities to reduce shrinkage caused by slow rooting, inconsistent growth, and transplant mortality. However, unknowns exist about the impact of light quality during vegetative propagation in controlled environments. Sungeun is evaluating various light-quality treatments that can promote early rooting and improve overall growth and quality of cuttings started indoors. Rare problems arising from indoor propagation such as intumescence are also being evaluated to improve quality of propagative material. 

Sofia Gómez (MS student at Purdue University) is evaluating how different environmental conditions affect water loss of unrooted cuttings (URC) acclimated in vertical indoor propagation (VIP) systems. Although starting young-plants in VIP systems can help growers produce high-quality transplants, optimal setpoints for temperature, relative humidity, light intensity and quality, and carbon dioxide (CO2) concentration are unknown. Sofia’s research is evaluating individual and interactive effects of these factors on water loss, rooting, and growth of URC to provide recommendations for growers interested in VIP systems.

Destany Westlake (M.S. student at UF) is researching heavy metal (HM) remediation in substrate to reduce contamination in medicinal hemp. Heavy metals such as arsenic (As), cadmium (Cd), and lead (Pb) are heavily regulated by the EPA and pose a significant risk to hemp growers and consumers due to the tendency of hemp to accumulate HM from production inputs such as fertilizers. Destany is working to find solutions to minimize the plant availability of heavy metals in growing media to reduce uptake into plants. One method for reducing availability of heavy metals in substrate is to use substrates with high cation exchange capacity (CEC) such as peat and biochar to adsorb heavy metal cations such as Cd and Pb to exchange sites. Another approach may be to increase soil pH to reduce the solubility and availability of heavy metals. This research will provide hemp growers with the ability to choose reliable substrates and substrate amendments that can minimize contamination in their hemp products for the safety of their consumers. 

Dharti Thakulla (PhD student) is researching the implementation of ozone and cold plasma technologies for water treatment. Microbial contamination of the nutrient solution is a key challenge faced by growers using recirculating systems or surface water supplies. She and undergraduate Heather Buss are running a series of experiments on dose response for cold plasma and ozone for controlling biofilm organisms and Pythium, in addition to effects on compatibility with micronutrient fertilizers and beneficial microbes.

Nelda Hernandez (Ph.D. student at UF) is assessing training needs in the horticultural workforce. She developed the “Professional Irrigator” grower training series (https://hort.ifas.ufl.edu/training), which combines online and hands-on activities on various irrigation topics. The goal of this training is to standardize staff training in irrigation practices to ensure high quality plants and effective water use. In addition to the human aspects of irrigation, Nelda is researching high-tech automation of irrigation for seedling plugs. Currently, irrigation decisions rely on subjective methods such as time-based schedules, grower experience, and tray weight. While helpful, these methods are not always objective or practical for commercial use. By using climate sensors to monitor air and leaf temperature, moisture levels, imaging with thermal and RGB cameras and by measuring physiological variables, Nelda’s research aims to establish objective parameters for irrigation decisions. This project will eventually expand to include sensors and cameras mounted on irrigation booms in greenhouses to map water needs and trigger automated irrigation events. 

Josh Tebow (M.Sc. student) is investigating strategies to keep nutrient levels on target in recirculating hydroponics. Managing nutrients in recirculating hydroponic solutions is complex, and the deviation of nutrient concentrations from their target levels (i.e. nutrient imbalance) can reduce yield and motivate growers to dump and replace solution. Nutrient levels continually fluctuate and are influenced by many interacting factors including supplied fertilizers, irrigation water quality, injection of acids and bases for pH control, water treatment, plant species and environmental conditions (light, temperature, gases). One strategy focuses on formulating a custom species-specific replacement solution designed to balance the replenishment of nutrients with plant uptake demand as well as stabilize solution pH. Another strategy consists of the previous strategy combined with regular nutrient testing and the periodic adjustment of the replacement solution formulation as needed. Josh aims to develop practical strategies and tools to help growers fine-tune nutrient management for optimal yields. 

Stephanie Cruz (Ph.D. student) is investigating the potential to produce blackberry crops using soilless “long-cane” techniques. Part of Stephanie's research focuses on determining how production factors such as transplant type and planting densities influence cane quality, flower bud development, and yield. Stephanie is also collaborating with commercial growers and the Agribusiness Department to develop a cost-benefit analysis and risk assessment tool. Her goal is to assist growers in understanding the key profitability drivers and evaluating both investment opportunities and risks for long-cane production.