Counts (e.g., number of leaves, fruits, seeds, or plants) are a common type of data gathered in horticultural research. In many instances, using ImageJ can increase the ease and accuracy of gathering count data. When image processing can easily separate objects of interest from the background, automatic counting with ImageJ can eliminate tedious manual counting processes. Furthermore, additional plant growth data, such as leaf area, plant width, and canopy area, can be collected from the same image. The image processing and analysis techniques introduced in this article are easily accessible and simple to use and thus can be adopted not only by researchers, but also by Extension agents and students. This new 10-page publication of the UF/IFAS Horticultural Sciences Department is part of a series introducing various image-based measurements with ImageJ for horticultural research. Written by Lillian Pride and Shinsuke Agehara.
Herbicide resistance was historically not a significant issue in most horticultural crops because few herbicides were applied. Close proximity of agronomic crops and the loss of methyl bromide has led to a gradual increase in herbicide inputs and the increased occurrence of herbicide-resistant weeds in tomato fields. Very few herbicides are registered for tomato, and resistance is a major concern. This new 11-page publication of the UF/IFAS Horticultural Sciences Department provides a definition of herbicide resistance, explains how it develops, and provides management recommendations for tomato growers. It was written for growers and Extension agents, but the information may be of interest to anyone concerned about herbicide resistance in vegetable and small fruit crops. Written by Shaun M. Sharpe, Nathan S. Boyd, Ramdas G. Kanissery, and Peter J. Dittmar.
Several different fungi and one bacterium cause leaf spot diseases of Florida strawberry. Symptoms caused by these pathogens are often similar, leading to confusion and misdiagnosis of the disease. To facilitate diagnosis, the most common leaf spots diseases of strawberry in Florida are described in this new 6-page article, written by Juliana S. Baggio, James C. Mertely, and Natalia A. Peres, and published by the UF/IFAS Plant Pathology Department.
This new 6-page article, part of a series introducing various image-based measurements for horticultural research, introduces a simple, inexpensive, and portable image-based technique for nondestructive leaf area measurements. It uses an imaging apparatus made with ordinary office supplies to obtain leaf images in greenhouse or field environments. Leaf images are then processed and analyzed to measure leaf area using ImageJ, an open-source image processing program. Because both image capture and analysis are performed nondestructively, leaf area can be measured on the same leaf repeatedly, enabling the monitoring of leaf growth over time, as well as photosynthesis and transpiration. This technique is particularly useful to researchers and students studying leaf growth and physiology in greenhouse or field environments. Written by Shinsuke Agehara, Lillian Pride, Mariel Gallardo, and Jose Hernandez-Monterroza, and published by the UF/IFAS Horticultural Sciences Department.
This new 13-page article combines canopy coverage data from all of Florida’s metropolitan and micropolitan areas with ecological models developed by the USDA Forest Service to calculate several key benefits of urban trees and an approximation of their monetary value. Benefits of urban trees include carbon sequestration/storage, air pollution filtration, and stormwater mitigation. Written by Drew C. McLean, Andrew K. Koeser, Deborah R. Hilbert, Shawn Landry, Amr Abd-Elrahman, Katie Britt, Mary Lusk, Michael G. Andreu, and Robert J. Northrop, and published by the UF/IFAS Environmental Horticulture Department.
Trees provide urban landscapes with shade, beauty, and habitat. They can also help lessen the effects of flooding and urban heat buildup while storing carbon dioxide, a major greenhouse gas. When planted in the wrong place, however, trees can damage urban infrastructure. To maximize the benefits provided by urban trees, we need better-informed tree selection and larger planting spaces with the capacity to support big-canopy trees. This new 8-page fact sheet is intended to help arborists, urban foresters, landscape designers, landscapers, and anyone else responsible for the planting of trees in developed areas make informed decisions regarding the planting width requirements of the trees they select. Written by Deborah R. Hilbert, Andrew K. Koeser, Brooke L. Moffis, JuWanda G. Rowell, and Drew C. McLean, and published by the UF/IFAS Environmental Horticulture Department.
Pestalotiopsis-like fungi cause diseases on many different species of plants worldwide, including strawberry. The pathogen is not necessarily new to strawberry and was first reported causing fruit rot in Florida and Israel in the 1970s. However, during the 2018–19 and 2019–20 strawberry seasons, severe and unprecedented outbreaks were reported in Florida, characterized by symptoms on nearly all plant parts including roots, crowns, petioles, fruit, and leaves. This new 4-page publication of the UF/IFAS Plant Pathology Department describes the disease and its causal agent and briefly covers what is known about disease development and control practices. This document will provide valuable information to strawberry nursery and fruit production growers. Written by Juliana S. Baggio and Natalia A. Peres.
This new 13-page article introduces simple image processing and analysis techniques to quantify leaf disease damage using ImageJ, an open-source image processing program. These techniques are not meant to replace crop scouting or disease diagnosis by a plant diagnostic laboratory, but rather to provide a supplemental tool for making quantitative measurements of leaf disease damage. Similar techniques are also available for plant growth assessment, including plant height, plant width, and canopy cover area. The image processing and analysis techniques introduced in this article are fairly simple to use and thus can be adopted not only by researchers, but also by producers, crop consultants, Extension agents, and students. Written by Lillian Pride, Gary Vallad, and Shinsuke Agehara, and published by the UF/IFAS Horticultural Sciences Department.
Hops (Humulus lupulus L.), an essential ingredient in beer, have potential to develop as a viable alternative crop in Florida. In our surveys, many breweries have expressed strong interest in using locally grown hops. However, hop production is plagued by many diseases, most of which were inadvertently introduced through the movement of contaminated planting material. The primary purposes of this new 7-page article are to prevent the introduction of these diseases into the state and to provide recommendations for selecting and preparing planting material for successful hop production in Florida. This publication of the UF/IFAS Horticultural Sciences Department is part of a larger series that will review the challenges of hop production, based on research experience at the UF/IFAS Gulf Coast Research and Education Center (UF/IFAS GCREC) in Balm, FL.
Hops (Humulus lupulus L.) are an emerging crop in Florida. Florida’s craft beer industry has experienced significant growth over the last 10 years, with 285 breweries producing 42.6 million gallons of beer and generating an economic impact of $3.6 billion in 2018. To respond to their strong demand for locally grown hops, an interdisciplinary hops research team is currently studying optimum crop management practices at the UF/IFAS Gulf Coast Research and Education Center (UF/IFAS GCREC). In Florida, the major yield-limiting factor is premature flowering induced by inadequate day length. This new 4-page article, written by Shinsuke Agehara and published by the UF/IFAS Horticultural Sciences Department, provides guidelines for supplemental lighting to control flowering of hops in Florida.
Hops (Humulus lupulus L.) are an essential ingredient in brewing, adding bitterness and flavor to beer. Driven by the recent craft beer movement, hop production is expanding into nontraditional hop-producing states. In Florida, while commercial hop production is almost nonexistent, the number of craft breweries in Florida increased from 45 in 2011 to 285 in 2018, and the economic impact of Florida’s craft beer industry exceeds $3 billion. This new 7-page article, written by Shinsuke Agehara, Aleyda Acosta-Rangel, Zhanao Deng, Jack Rechcigl, and Simon Bollin and published by the UF/IFAS Horticultural Sciences Department, provides guidelines and considerations for building a hop yard in Florida, using the UF/IFAS Gulf Coast Research and Education Center’s research hop yard as a model.
Blackberry (Rubus spp.) is a deciduous berry crop and the fourth most economically important berry crop in the United States. Driven by the growing demand for blackberries, production recently expanded to the southeastern United States. In Florida, however, commercial blackberry production is limited primarily to small commercial U-pick operations. The main challenges include insufficient chill hours and poor fruit quality associated with the subtropical climate. This new 6-page article, a publication of the UF/IFAS Horticultural Sciences Department, will discuss important cultivar selection criteria and recommended blackberry cultivars in subtropical Florida. Written by Shinsuke Agehara, Syuan-You Lin, and Zhanao Deng.
Bacterial spot is one of the most detrimental diseases of tomato and is especially severe in the southeast United States when weather conditions (high temperature, high humidity, and rain) become conducive for disease development. This new 8-page publication of the UF/IFAS Plant Pathology Department presents updated information about the causal pathogen and management of bacterial spot on tomato in Florida. Written by Amanda Strayer-Scherer, Ying-Yu Liao, Peter Abrahamian, Sujan Timilsina, Mathews Paret, Tim Momol, Jeff Jones, and Gary Vallad.
Fresh-market tomatoes bring in $400-$500 million annually as the third most valuable crop in the state. Defoliation and fruit damage from target spot, caused by Corynespora cassiicola, can have serious economic implications for growers. This new 5-page publication of the UF/IFAS Plant Pathology Department, written by Keevan MacKenzie, Jessica Chitwood, Gary Vallad, and Sam Hutton, reviews symptoms and epidemiology of the disease and provides current management recommendations.
Many Florida growers are interested in the potential of pomegranate as an alternative fruit crop. The first flush of flowers produces the best quality fruit, and climatic conditions have a great impact on the timing of flowering. Proper fertilization is critical to promote healthy canopy development, minimize nutrient disorders, and maximize fruit yield and quality. This new 5-page article, written by Shinsuke Agehara, Weining Wang, and Ali Sarkhosh and published by the UF/IFAS Horticultural Sciences Department, provides guidelines for pomegranate nutrient management in Florida.
This new 3-page article describes Phytophthora crown rot, an important disease in Florida strawberry fields caused mainly by Phytophthora cactorum, and provides some recommendations for cultural and chemical control. Written by Natalia A. Peres and Juliana S. Baggio and published by the UF/IFAS Plant Pathology Department.
Florida strawberry growers primarily utilize cultivars developed by the UF/IFAS Strawberry Breeding Program. These cultivars are bred to provide the yield and quality traits needed by the Florida industry. Yet if a new cultivar has the traits that Florida growers need but pathogen-tested planting stock is not available to growers, the cultivar’s impact will be limited. The Clean Plant Program generates the pathogen-tested planting stock that nurseries and growers require. This new 5-page publication of the UF/IFAS Horticultural Sciences Department, written by Catalina Moyer, Natalia A. Peres, and Vance M. Whitaker, is intended to educate both the industry and the public on the importance of the Clean Plant Program and the methods used to produce planting stock of new cultivars.
Recently, new plant-breeding technology such as CRISPR gene editing has provided the potential to substantially improve crop breeding in agriculture. Considerable efforts have been devoted to apply this gene-editing technology in modern agriculture to increase crop yields and improve the quality of food ingredients, especially by many of the major agronomic seed-producing companies. In this new 4-page article, we outline the recent research updates and regulations on gene editing in crop improvement. Written by Sadikshya Sharma, Heqiang Huo, and Seonghee Lee and published by the UF/IFAS Horticultural Sciences Department.
All eight species of Bidens in Florida are commonly referred to as Spanish needles or beggar-ticks. This document focuses on Bidens alba and B. pilosa, which are common weeds in container nurseries and landscapes in Florida. This 6-page EDIS publication, written by Yuvraj Khamare, Chris Marble, Shawn Steed, and Nathan Boyd and published by the UF/IFAS Environmental Horticulture Department, is designed for landowners, gardeners, horticulturalists, and consumers hoping to learn more about Spanish needle classification and management.
This new six-page document provides insight on characteristics and management techniques for both yellow and purple nutsedge, prevalent and persistent weeds in Florida. Written by Debalina Saha, Chris Marble, Nathan Boyd, and Shawn Steed and published by the UF/IFAS Environmental Horticulture Department, March 2019.