Optimizing Planting Density to Increase the Sustainability of Blueberry Farms

Project Overview

Project Type: Graduate Student
Funds awarded in 2023: $16,417.00
Projected End Date: 08/31/2025
Grant Recipient: University of Florida
Region: Southern
State: Florida
Graduate Student:
Major Professor:
Dr. Gerardo Nunez
University of Florida


  • Fruits: berries (blueberries)


  • Crop Production: application rate management, fertilizers, nutrient management, water management, planting density

    Proposal abstract:

    Blueberry farms in the southeastern United States have a high potential for water and nutrient leaching. In other crops, increasing planting densities improve water and nutrient uptake efficiency and reduces nutrient losses. This project aims to improve the sustainability of blueberry farms by determining the optimum number of plants per unit area to optimize water and fertilizer use efficiency. We will evaluate the nutrient use efficiency (NUE) and water use efficiency (WUE) in two southern highbush blueberry varieties (‘Sentinel’ and ‘Chickadee’) grown at low- (1,613 plants/acre), standard- (1,936 plants/acre), and high-planting density (2,420 plants/acre) in an experimental field at the UF Plant Science Research and Education Unit in Citra, FL. Canopy volume, light interception, yield, fruit quality, NUE, and WUE will be measured and compared between density treatments for two seasons. We will disseminate our results through standard (extension publications), and non-standard outlets (social media). This study will generate informational tools about the planting density that brings about greater WUE and NUE for growers to make informed decisions that improve the sustainability of blueberry production.

    Project objectives from proposal:

    The goal of this project is to improve the sustainability of blueberry farms by determining the ideal planting density that results in the optimization of water and fertilizer use efficiency. Specific objectives are:

    Objective 1: Evaluate nutrient use efficiency (NUE) and water use efficiency (WUE) in blueberry plants grown at different planting densities.

    Activity 1.1: Plant a research trial with two blueberry varieties spaced 24 inches, 30 inches, and 36 inches apart.

    Activity 1.2: Measure WUE, NUE, canopy volume, canopy light penetration, and marketable fruit for two consecutive seasons.


    Objective 2: Disseminate research findings among growers, extension educators, and scientists.

    Activity 2.1: Publish two articles in trade journals such as The Blueberry News (Aug of 2024 and 2025) and one extension publication in English and Spanish (December 2025).

    Activity 2.2: Share brief updates and media (photos and videos) in social media like Twitter. Scientists and young people with and without a horticulture background will be the target audience for these media.

    Activity 2.3: Organize a field day to showcase plant performance during the production period (March 2025).

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.