University of Florida IFAS Extension Agents Stay Engaged by Serving Watermelon Farmers

By Robert Hochmuth, Regional Extension agent, North Florida Research and Education Center - Suwannee Valley, Live Oak, FL

Watermelons are grown throughout the sunshine state and therefore, growers have a wide array of production, pest and marketing challenges needing research. UF/IFAS Extension agents and specialists serve the needs of watermelon farmers in a wide array of research projects and Extension methods. Robert Hochmuth, UF/IFAS Regional Extension Agent at the North Florida Research and Education Center- Suwannee Valley works closely with the Florida Watermelon Association (FWA) to enhance opportunities to identify, and successfully implement needed research projects, including securing grant funding. This strategic leadership between the two institutions, the partnership has been strengthened in the past several years as evidenced by the increase in active watermelon research projects and the increase in Extension educational opportunities at the FWA Annual Conference and other meetings such as the Suwannee Valley Watermelon Institute. Several of the UF/IFAS Research and Education Centers (RECs) throughout the state are hosting research trials for a wide range of topics important to the watermelon industry in Florida. Major watermelon research projects are being or have recently been conducted at RECs in Homestead, Immokalee, Balm, Live Oak, and Quincy as well as the UF/IFAS Plant Science Research and Education Unit at Citra. In most cases, as research priorities are identified by FWA and later projects being developed by UF/IFAS faculty, letters of support from FWA are submitted and strengthen the proposals knowing the industry is involved in the planning of the research and in several instances FWA provides funding support as well. In the past few years, on average, 15-20 research projects representing $1.5 to nearly $2.0 million being funded by several public and private sources.

A group of several Extension agents in the Suwannee Valley working with watermelon growers formed a team to plan and implement several educational activities for watermelon growers. One of those efforts in 2020 was to initiate the development of a watermelon pictorial guide for growers and allied industry. The initial printing of 500 copies was funded ($5,000) by Florida Watermelon Association. Two reprintings of 250 more copies each time have been needed and have been funded by the sale of the previously printed copies. The publication has received national recognition with several state watermelon associations buying the guides for their members and the National Promotion Board reprinting the Hollow Heart information on their Watermelon.org website. The field guide authors include Tatiana Sanchez, Bob Hochmuth, Tyler Pittman, Mark Warren, Sylvia Willis, Luke Harlow, Jay Capasso, Danielle Sprague and Dan Fenneman. Along with other agents in the region, this group offers a comprehensive extension service in 10 watermelon producing counties.  The guide is available for purchase at (https://ifasbooks.ifas.ufl.edu/p-1636-watermelon-field-guide.aspx).

Several common watermelon diseases and insects cause significant yield losses to area growers each year and each year the timing and severity of pests and diseases may vary greatly. In 2021, Extension agents in the Suwannee Valley developed an “Early Disease and Insect Detection Program” whereby samples of diseased leaves or other aspects can be immediately submitted by the County Extension Agent to one of the UF/IFAS Plant Diagnostic Lab for diagnosis. This program is funded by allied watermelon industry sponsors to pay for the dozens of samples at $40 per sample. This program is intended to be able to more quickly identify the first and early detection of major diseases such as downy mildew and powdery mildew, and major pest activity such as rindworms and spider mites. Early detection is the key, and this intensive program helps Extension to alert growers when major problems are emerging. In 2023 watermelon diseases were prevalent and the early and proper ID by this program helped growers save an estimated $50- 200 per acre on at least 7,500 acres. This was based on grower survey data collected at the end of the season. The impact of this long-term program has been improved yields and reduced losses from diseases.

The early detection program and other guidance is shared weekly through the Suwannee Valley Weekly Watermelon Update, an electronic newsletter shared via emails or text via an app. The weekly update is certainly useful to share new disease detections, for instance, but also serves as a mechanism to share information on irrigation and nutrient management recommendations, announcements for field days and pesticide applicator trainings and many other important topics during the season. Extension agents, crop consultants, allied industry reps and farmers all work together to help the farmers by providing timely and critical information.

UF/IFAS regional efforts include the Suwannee Valley Watermelon Institute held in Fanning Springs and typically two on-farm field days which are planned and conducted by the Extension agents in the region. These Suwannee Valley Watermelon Institute program has become the featured educational event for area watermelon farmers and allied industry reps with approximately 175 people or more attending each year and the field days also attract 50-75 attendees each.

UF/IFAS Extension agents are always looking for ways to help their growers be as environmentally and economically sustainable as possible. This is achieved by helping farmers to adopt Best Management Practices (BMP). Many of these types of efforts are in the form of large scale on-farm activities and demonstrations. One such program is petiole sap testing for nitrate-nitrogen and potassium. This fosters one-on-one interaction with growers at their farm locations during various growing seasons to help fine tune their nutrient management practices. Petiole sap testing can be performed on a variety of crops, however, in the Suwannee Valley, it is most commonly used on crops like watermelon, tomato, pepper, cantaloupe, and strawberry. During peak season, UF/IFAS Extension agents and staff in the Suwannee Valley collect petiole sap samples across approximately 100 fields each week, representing over 5,000 acres! The procedure involves removing the petioles from the leaf and cutting them into smaller pieces that will fit into the garlic press to test the petiole sap by squeezing the sap onto the meters and taking the measurement. After the results have been recorded, agents relay the numbers to the growers to help them make the best fertilization decisions for their growing crop.  These agents surveyed growers (after the 2023 season) who were voluntarily involved in the free petiole-sap testing service provided by UF/IFAS Extension Agents to determine the impacts on their farm. As a result of this program in 2023, growers reported that, on average, petiole sap testing allowed them to reduce fertigation events on 5,640 acres of watermelons resulting in the reduction of approximately 69,090 total lbs of both nitrogen and potash! In some cases, no reduction was found but the growers all felt the sap testing program helped them fine tune their fertigations.