Empowering Northeastern Strawberry Growers With Flower Mapping

Project Overview

Project Type: Research and Education
Funds awarded in 2020: $137,819.00
Projected End Date: 11/30/2023
Grant Recipient: Dept. of Plant Biology, Rutgers University
Region: Northeast
State: New Jersey
Project Leader:
Edward Durner
Dept. of Plant Biology, Rutgers University


  • Fruits: berries (strawberries)


  • Crop Production: application rate management, cropping systems, fertigation, fertilizers, high tunnels or hoop houses, nutrient management
  • Education and Training: demonstration, mentoring, technical assistance, workshop

    Proposal abstract:

    Problem and Justification: Current recommendations for fall nitrogen application and row cover management in annual strawberry plasticulture are based on tradition and calendar date. Decisions regarding both practices would be more appropriately based on the floral status of plants in production. Pre-plant N normally provided plasticulture strawberries is unnecessary: it does not improve yield. However, targeted weekly pulses of N for 3 consecutive weeks starting one week after floral initiation begins in the fall significantly enhances subsequent yield. Row covers applied to strawberries in the fall at the appropriate time increase yield the following spring by increasing the number of flowers per plant and protecting plants from excessive cold during dormancy. Growers fertilize with N and apply row covers based on tradition and calendar date without any knowledge of the floral status of their plants. Flower mapping is used to to evaluate a plants floral status. While widely used in Europe, flower mapping has not been developed for US growers and data illustrating its usefulness for North American production has not been generated. Solution and Approach: Flower mapping is not difficult and growers could easily learn the technique. Strawberry growers taught how to flower map and interpret the results would be able to make science-based decisions regarding production practices rather than relying on tradition or calendar date. Precisely timed nitrogen fertilization and row cover applications based on floral mapping would improve yields and empower growers with a new management tool. Basing decisions on self-generated knowledge rather than tradition or calendar date would reduce grower stress associated with these decisions. In addition, the chances for over-fertilization with N and the associated environmental risks would decrease. Growers supplied with flower mapping kits and taught to flower map at one of 3 regional grower meetings would then employ flower mapping on their farms, submit maps to us via e-mail and interpret their maps with our help to evaluate management choices for their specific situation. Milestones and Performance Target: Seventy-five growers will adopt strawberry flower mapping as a management tool to properly time fall N applications and efficiently manage row cover placement based on farm-specific data which will significantly increase yields on their farms. Considering even only modest yield improvements much less then that reported in the literature (350 to 500%), a conservative estimate of a 25% increase would translate into a minimum of an additional $1,000 an acre (at $1.00 per lb) due to use of flower mapping. In addition, eliminating ineffective traditional pre-plant N fertilization by substituting it with targeted N pulses would reduce N application by 20 lbs/acre, saving growers money, improving yields and reducing the chances of environmental contamination from unnecessary N fertilization.

    Performance targets from proposal:

    Science-based decisions using flower mapping will replace tradition and calendar based recommendations for N fertilization and row cover management to increase grower confidence and reduce stress with enhanced yields of 1,000 lbs per acre on at least one acre per farm on seventy-five farms in the Northeast.

    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.