Yuncong Li

0000-0001-6331-083X

Questions and Answers for Using Sunn Hemp (Crotalaria juncea L.) as a Green Manure Cover Crop

Thioro Fall, Ariel Freidenreich, Stacy Swartz, Christopher Vincent, Yuncong Li, and Zachary Brym

This document synthesizes information about the warm-season cover crop, sunn hemp. It addresses frequently asked questions for growers and summarizes the expanding body of sunn hemp research. The information is provided so growers in Florida can learn about up-to-date cultivation and management options as well as better understand sunn hemp's practical uses. This document is a follow-up to EDIS publications SL 306 (https://edis.ifas.ufl.edu/tr003) and ENY-717 (https://edis.ifas.ufl.edu/ng043).

ET-Based Irrigation Scheduling for Papaya (Carica papaya) in Florida

Haimanote K. Bayabil, Jonathan H. Crane, Kati W. Migliaccio, Yuncong Li, and Fredy Ballen

Calcareous Soils In Miami-Dade County

Yuncong Li

Alternatives of Low Cost Soil Moisture Monitoring Devices for Vegetable Production in South Miami-Dade County

Rafael Muñoz-Carpena, Yuncong Li, and Teresa Olczyk

Soil Arsenic in Miami-Dade County

Yuncong Li, Ashley Smyth, Jonathan Crane, Christopher Teaf, and Guangliang Liu

Indoor Vertical Farming Systems for Food Security and Resource Sustainability

Jiangxiao Qiu, Haimanote K. Bayabil, and Yuncong Li

Drip Irrigation: The BMP Era—An Integrated Approach to Water and Fertilizer Management for Vegetables Grown with Plasticulture

Eric Simonne, David Studstill, Bob Hochmuth, Teresa Olczyk, Michael Dukes, Rafael Munoz-Carpena, and Yuncong Li

Wetland Delineation: An Overview of Regulations and Methods

Daniel L. Irick, Yuncong Li, and Alan L. Wright

Alternaria Leaf and Pod Spot of Snap Bean in Florida

Shouan Zhang, Aaron J. Palmateer, Ken Pernezny, and R. T. McMillan, Jr.

Soil-Test-Based Phosphorus Recommendations for Commercial Agricultural Production in Florida

Rao Mylavarapu, Yuncong Li, Maria Silveira, Cheryl Mackowiak, and Mabry McCray

Controlled-Release Fertilizers for Commercial Potato Production in Florida

Guodong Liu, Eric H. Simonne, Yuncong Li, Chad M. Hutchinson, Mark Warren, and Steven Lands

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Grower’s Guide to Identifying and Correcting Nitrogen, Phosphorus, and Potassium Deficiencies in Luffa Production

Md Jahidul Islam Shohag, Qiansheng Li, Yuncong Li, Qingren Wang, and Guodong Liu

Luffa, referring to the smooth (Luffa aegyptiaca Mill.) and angled (Luffa acutangular (L.) Roxb.) types, is a climbing vegetable from the family Cucurbitaceae that has grown for centuries across Asia. Luffa are consumed as vegetables when immature and used as natural sponges when mature. Luffa is gaining popularity as an alternative vegetable crop in regions like Florida and California, thanks to favorable growing conditions and rising demand for Asian specialty produce. Successful cultivation of luffa relies heavily on proper nutrient management, particularly for nitrogen (N), phosphorus (P), and potassium (K) because mismanagement can lead to deficiencies that cause stunted growth, leaf discoloration, and reduced yields. Early diagnosis and intervention are crucial for ensuring healthy growth and maximizing profitability. This Extension publication provides practical guidance for growers, Extension agents, and students on identifying and correcting N, P, and K deficiencies in luffa.

What Else Can Surface Water Buffer Systems Do? Exploring Multiple Ecosystem Services

Ashley R. Smyth, Lei Wu, Rafael Muñoz-Carpena, and Yuncong Li

This fact sheet provides information on buffers' multiple ecosystem benefits, such as niche products production, carbon sequestration, and flood risk mitigation, as well as recommendations on future research needs necessary to enhance multiple ecosystem services and benefits of buffers.

Cabbage Production in Miami-Dade County, Florida

Y. C. Li, W. Klassen, M. Lamberts, Teresa Olczyk, and Guodong D. Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Planning for a Successful Commercial Subtropical/Tropical Fruit Grove

Jonathan Crane, Yuncong Li, Edward Evans, Fredy Ballen, and Jeff Wasielewski

Planning is the key to successful grove establishment, maintenance, and production. Developing a detailed infrastructure description and plan, cultural program, and financial and marketing plan for a new or existing grove with a new fruit crop will save you time and money and help minimize mistakes. Prospective growers should compile and analyze information needed to select a grove site, establish the needed infrastructure, and develop maintenance plans for the plants and how the production will be marketed. This publication presents an outline of the type of information growers need when establishing a tropical fruit grove or contemplating management or modification of an existing grove.

Conversions of Parts per Million on Soil Test Reports to Pounds per Acre

Guodong Liu, Yuncong Li, and Aparna Gazula

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Animal Systems

Moisture Retention and Chemical Properties of Nursery Potting Substrates

Haimanote K. Bayabil, Fitsum T. Tilahun, Yuncong Li, and E. Vanessa Campoverde

This publication provides general information about differences in moisture retention characteristics and chemical properties of most common potting substrates used by the nursery industry in south Florida. Written by Haimanote K. Bayabil, Fitsum T. Tilahun, Yuncong Li, and E. Vanessa Campoverde, and published by the UF/IFAS Department of Agricultural and Biological Engineering, October 2021.

Pond Apple—A Tree Species Adapted to Salt Stress

Guodong Liu, Yuncong Li, Kimberly Moore, and Kim Gabel

This document provides an overview of the Pond Apple (Annona glabra L.), a semi-deciduous tree native to Florida and Puerto Rico. It highlights the tree’s tolerance to salt and flooding, making it suitable for high-salinity coastal landscapes. The Pond Apple can grow up to 10 feet and produces edible fruit similar to custard apples. Ecologically, it is important as its fruit is consumed by wildlife, and its seeds are dispersed by animals. The tree has various uses, including its edible fruit and medicinal properties, with potential anticancer chemicals. Compared to the bald cypress, it is more salt-tolerant but may suffer from iron deficiency in dry conditions. 

Determination of Carbonate Concentrations in Calcareous Soils with Common Vinegar Test

Qiang Zhu, Yuncong Li, Guodong Liu, and Monica Ozores-Hampton

A UF/IFAS numbered Fact Sheet in support of UF/IFAS Extension program: Integrated Pest Management

Okra Production in Miami-Dade County, Florida

Y. C. Li, W. Klassen, M. Lamberts, T. Olczyk, and Guodong Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Pepper Production in Miami-Dade County, Florida

Qingren Wang, Shouan Zhang, Yuncong Li, Dakshina Seal, Waldemar Klassen, and Teresa Olczyk

This publication provides general information and guidelines for pepper growers in Miami-Dade County, including major pepper varieties, their horticultural traits, and fundamental soil and water management requirements. A minor revision of the UF/IFAS Horticultural Sciences Department by Qingren Wang, Shouan Zhang, Yuncong Li, Dakshina Seal, Waldemar Klassen, and Teresa Olczyk; 9 pp.

Implementing the Four Rs (4Rs) in Nutrient Stewardship for Tomato Production

Qingren Wang, Guodong Liu, Kelly Morgan, and Yuncong Li

A UF/IFAS numbered Fact Sheet for Commercial audience(s). in support of UF/IFAS Extension program: Integrated Pest Management

Nutrient Management Recommendations Based on Mehlich-3 Extractant for Calcareous Soils in Miami-Dade County

Yuncong Li, Qiang Zhu, Rao Mylavarapu, Kelly Morgan, Guodong Liu, Jonathan Crane, Qingren Wang, Henry Mayer, Jeff Wasielewski, Laura Vasquez, Qingchun Liu, and Teresa Olczyk

This factsheet provides information about the history of soil testing calibrations and justification for recommending extraction of soil nutrients using Mehlich-3 for calcareous soils in Miami-Dade County. The dominant soils from this County have an extraordinarily high concentration of calcium resulting in high pH. This document also includes UF/IFAS approved Mehlich-3 extractant-based testing interpretations and recommendations for these soils. The purpose of this publication is to elucidate an appropriate approach for analyzing the unique calcareous soils from Miami-Dade County for plant available nutrients. The target audiences are Extension agents, agronomists at soil testing laboratories, crop advisors, growers, representatives of the state and local agencies, and others concerned about soil testing and plant analysis in Miami-Dade County.

Summer Squash Production in Miami-Dade County, Florida

D. Seal, S. Zhang, P. Dittmar, Y. C. Li, W. Klassen, Q. Wang, and T. Olczyk

Summer squash is an important vegetable crop in Miami-Dade County. It is grown annually on about 6,000 acres and sold nationwide during the winter in the fresh market. This 16-page fact sheet describes the varieties of summer squash, land preparation and transplanting, what fertilizer to use, irrigation and freeze protection, disease management, insect management, weed management, harvest, and crop rotation.

Are Phosphorous and Phosphoric Acids Equal Phosphorous Sources for Plant Growth?

Asha M. Brunings, Guodong Liu, Eric H. Simonne, Shouan Zhang, Yuncong Li, and Lawrence E. Datnoff

A UF/IFAS numbered Fact Sheet.

Sunn Hemp—A Promising Cover Crop in Florida

Qingren Wang, Yuncong Li, Waldemar Klassen, and Edward A. Hanlon Jr.

As one of the promising cover crops under tropical, subtropical, or even template climate, sunn hemp (Crotalaria Juncea L.) has shown great advantages in improving soil fertility and increasing the yield and quality for subsequent cash crops. Due to the leguminous feature, sunn hemp can grow well in the soil with poor fertility, grow fast, accumulate a significant amount of nitrogen from soil, suppress weeds and soil root-knot nematodes, and tolerate dry and wet environmental conditions. Therefore, this article aims to elucidate unique features, origin, plant growth, handling, potential benefits, and the limitation in seed production of sunn hemp. It provides basic information to growers, stakeholders, and anyone interested in growing cover crops for crop rotation to optimize the cropping systems for sustainable agriculture.

Phosphorus Dynamics and Impacts on Potato Production in Northeast Florida

Joris D. Van Zeghbroeck, Guodong (David) Liu, and Yuncong Li

Florida is one of two states (FL and CA) that produce spring potatoes, FL having the highest crop value out of any state in the country ($469.67 per ton). Due to the low phosphorus use efficiency (PUE), high rates of phosphorus (P) are applied to ensure adequate yields. This has led to a buildup of legacy P, resulting in mehlich-1 levels as high as 375 mg kg-1. These levels are significantly higher than the critical values for potatoes (25-35 mg kg-1), yet farmers still report increased yields with P applications. Several organic amendments, management practices, and new fertilizers have been shown to help increase P availability in potato cropping systems by reducing P fixation and maximizing the available P fraction throughout the growing season. New fertilizers and management strategies should be researched in the TCAA to find methods that maintain yields while reducing the environmental impact of potato cropping systems.

Nickel Nutrition in Plants

Guodong Liu, E. H. Simonne, and Yuncong Li

This 5-page fact sheet introduces agricultural and horticultural producers to the role and function of the newest identified essential plant nutrient, nickel (Ni).

Cover Crop Benefits for South Florida Commercial Vegetable Producers

Q. Wang, Y. Li, E. A. Hanlon, W. Klassen, T. Olczyk, and I. V. Ezenwa

This document describes the use of major cover crops grown in southern Florida. The intent of this document is to identify promising cover crops adaptable to Florida's climate. Identified cover crops must also contribute to nutrient conservation and improve soil organic matter by incorporation of cover crop biomass. This document also includes discussion of other aspects of cover crop use in the vegetable production systems of south Florida.

Tong Hao—an Asian Vegetable Expanding in Florida

Guodong Liu, Qingren Wang, Bonnie Wells, Yuncong Li, and David Dinkins

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Understanding Fertilizers and Soil Amendments

Niguss Solomon Hailegnaw, Guodong Liu, and Y. C. Li

Choosing the right fertilizer/amendment type (organic or inorganic/synthetic) can impact soil health, plant vigor, environmental sustainability, and overall farm profitability. This guide provides a comparison of organic fertilizers/amendments and inorganic/synthetic fertilizers/amendments, covering their differences, advantages, disadvantages, and impacts on soil to aid growers in making informed decisions. Written by Niguss Solomon Hailegnaw, Guodong Liu, and Y. C. Li, and published by the UF/IFAS Department of Agronomy, October 2025.

Chapter 5. Ethnic Vegetable Production

Guodong Liu, Bonnie Wells, Yuncong Li, Qingren Wang, Johan Desaeger, and Xiaoying Li

Chapter 5 of the Vegetable Production Handbook of Florida

Indigo from Indigofera spp.: Historical and Cultural Overview

Pamela Moon, Yuncong Li, Geoffrey Meru, Wagner Vendrame, Terence Molnar, and Xingbo Wu

This EDIS publication is to introduce indigo as a new economic crop in south Florida. It highlights the historical and cultural background, including identification and distribution, uses, and history of indigo. The information included in this publication could be of interest to researchers, students, extension agents, growers, the dye industry, and the public.

Saltwater Intrusion and Flooding: Risks to South Florida’s Agriculture and Potential Management Practices

Haimanote K. Bayabil, Yuncong Li, Jonathan H. Crane, Bruce Schaffer, Ashley R. Smyth, Shouan Zhang, Edward A. Evans, and Trent Blare

This article highlights the impacts of saltwater intrusion and flooding on the health of agricultural soils. It also discusses management practices to reduce the negative impacts of soil salinity due to saltwater intrusion and/or flooding. Written by Haimanote K. Bayabil, Yuncong Li, Jonathan H. Crane, Bruce Schaffer, Ashley R. Smyth, Shouan Zhang, Edward A. Evans, and Trent Blare, and published by the UF/IFAS Department of Agricultural and Biological Engineering, May 2022.

Cucumber Production in Miami-Dade County, Florida

Y. C. Li, W. Klassen, M. Lamberts, and T. Olczyk

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Snap Bean Soil Fertility Program in Miami-Dade County

Monica Ozores-Hampton, Qiang Zhu, Yuncong Li and Guodong Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s). in support of UF/IFAS Extension program: Plant Systems

A Practical Guide for Adjusting Fertigation Water pH in Specialty Crop Production

Guodong Liu, Md Jahidul Islam Shohag, Lisa Hickey, Yuncong Li, and Shufang Tian

Fruit and vegetable producers have widely adopted fertigation as a common practice. However, achieving optimal nutrient use efficiency and growth of crops requires careful management of the irrigation water’s pH, especially when the water quality exhibits excessive acidity or alkalinity. Adjusting the pH of irrigation water is crucial to meet crop preferences and ensure optimal conditions for growth. Growers frequently encounter challenges in effectively optimizing irrigation water pH. This publication aims to address this issue by providing an overview of adjusting irrigation water pH and offering practical guidelines. The target audiences of this guide are farm/nursery managers, growers, crop advisors, Future Farmers of America (FFA), Extension agents, researchers, students, and others who are interested in crop production.

Symptoms of Nitrogen and Iron Deficiency in Luffa

Qiansheng Li, Marina Gluck, Yanlin Wang, Wendy Mussoline, Qingren Wang, Yuncong Li, and Guodong Liu

Luffa (Luffa aegyptiaca, synonym Luffa cylindrica) is a tropical and subtropical climbing plant belonging to the cucumber family (Cucurbitaceae), natively cultivated in South and Southeast Asia. There are two main species of luffa grown in Florida: smooth luffa (Luffa aegyptiaca Mill.), primarily grown in small gardens and angled luffa (Luffa acutangula (L.) Roxb.), basically grown for commercial production (https://edis.ifas.ufl.edu/publication/HS1285). It is commonly called sponge gourd, Egyptian cucumber, or Vietnamese luffa. Young fruits are edible and rich with nutritional and medicinal value (Partap et al. 2012; Azeez, Bello, and Adedeji et al. 2013). The mature fruit has strong fibrous insides, which can be used as natural porous fiber (Siqueira, Bras, and Dufresne 2010; Sivakandhan et al. 2020) for dishwashing or shower scrubbing. This publication is written for growers, state and county Extension faculty, and students interested in crop production.

What is 4R nutrient stewardship?

Guodong Liu, Kelly T. Morgan, Yuncong Li, Lincoln Zotarelli, Qingren Wang, and James DeValerio

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Integrated Pest Management

Eggplant Production in Miami-Dade County, Florida

Y.C. Li, W. Klassen, M. Lamberts, T. Olczyk, and Guodong Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Sweet Corn Production in Miami-Dade County, Florida

Haimanote Bayabil, Yuncong Li, Teresa Olczyk and Guodong Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Tomato Production in Miami-Dade County, Florida

Y. C. Li, W. Klassen, Mary Lamberts, Teresa Olczyk, and Guodong Liu

A UF/IFAS numbered Fact Sheet for Commercial audience(s).

Long Bean—an Asian Vegetable Emerging in Florida

Guodong Liu, Qingren Wang, Yuncong Li, David Dinkins, Bonnie Wells, and Kshitij Khatri

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Understanding and Applying Chelated Fertilizers Effectively Based on Soil pH

Guodong Liu, Edward Hanlon, and Yuncong Li

A UF/IFAS numbered Fact Sheet.

Histosols of South Florida: Past, Present, and Future

Xue Bai, Yuncong Li, Noel Manirakiza, Christine Coffin, and Jehangir H. Bhadha

This factsheet presents a comprehensive overview of Histosols, also known as organic soils, in South Florida, focusing on their distribution, formation, properties, and significance. Histosols cover significant areas in Florida, especially within the Everglades Agricultural Area (EAA), and are pivotal in supporting the region's sugarcane production. Their formation is influenced by organic parent materials, the tropical climate, vegetation types, topography, and time, which together shape their unique chemical, physical, and biological properties. Moreover, this publication reviews past developments and anticipates future changes in Histosol classification and management. By revealing the past, present, and future of Histosols in South Florida, this publication can help improve land management in the region and enhance the understanding of Histosols for audiences including agricultural producers, Extension agents, state and local agencies, decision-makers, researchers, and students.

How to Chemigate Salinity-Stressed Plants with Hydrogen Peroxide to Increase Survival and Growth Rates

Guodong Liu, Yuncong Li, Kimberly Moore, Kim Gabel, Lei Wu, and Rafael Muñoz-Carpena

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Irrigation Scheduling Tips for Tropical Fruit Groves in South Florida

Haimanote K. Bayabil, Kati W. Migliaccio, Jonathan H. Crane, and Yuncong Li

This fact sheet provides irrigation scheduling tips to growers of tropical fruit (e.g., avocado, mango, papaya, etc.) in south Florida. Written by Haimanote K. Bayabil, Kati W. Migliaccio, Jonathan H. Crane, and Yuncong Li, and published by the UF/IFAS Department of Agricultural and Biological Engineering, revised September 2022.

Practices to Minimize Flooding Damage to Commercial Vegetable Production

Guodong Liu, Yuncong Li, Xiangju Fu

A UF/IFAS numbered Fact Sheet for Commercial audience(s). in support of UF/IFAS Extension program: Plant Systems

Controlled-Release and Slow-Release Fertilizers as Nutrient Management Tools

Guodong Liu, Lincoln Zotarelli, Yuncong Li, David Dinkins, Qingren Wang, and Monica Ozores-Hampton

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Urban Water

How to Fertigate Plant Vines via Center Pivots for Commercial Potato Production in Florida

Xiangju Fu, Guodong Liu, Lincoln Zotarelli, Steven Sargent, Kati Migliaccio, and Yuncong Li

Potatoes are an important crop in the United States, and Florida is ranked the 7th producer nationwide for potato production. In Florida, potatoes are mainly planted on sandy soils with low nutrient- and water-holding capacities. Nitrogen is the most limiting nutrient in these soils. Adopting efficient fertilization methods such as fertigation is imperative for minimizing leaching and improving use efficiency of nitrogen. This new 12-page article provides step-by-step guidelines for fertigation practices for commercial potato production.

Bitter Melon—an Asian Vegetable Expanding in Florida

Guodong Liu, Qingren Wang, Yuncong Li, David Dinkins, Bonnie Wells, and Yuqi Cui

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Long Squash—an Asian Vegetable Expanding in Florida

Guodong Liu, Yuncong Li, David Dinkins, Bonnie Wells, Qingren Wang, and Yuqi Cui

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Programación de riego basado en el método de evapotranspiración para papaya (Carica papaya) en Florida

Haimanote K. Bayabil, Jonathan H. Crane, Kati W. Migliaccio, Yuncong Li, Fredy Ballen y Sandra Guzmán

A UF/IFAS numbered Translation. Published by Agriculture Water

Luffa—an Asian Vegetable Emerging in Florida

Yucong Xie, Guodong Liu, Yuncong Li, and Kati Migliaccio

A UF/IFAS numbered Fact Sheet. in support of UF/IFAS Extension program: Plant Systems

Vegetative Filter Strips—A Best Management Practice for Controlling Nonpoint Source Pollution

Ashley Smyth, Lei Wu, Rafael Muñoz-Carpena, and Yuncong Li

A UF/IFAS numbered Fact Sheet. Published by Agriculture Water