Systems approaches to co-manage disease, water and soil health for sustainable processing tomato production in the Western region

Project Overview

Project Type: Graduate Student
Funds awarded in 2019: $25,000.00
Projected End Date: 01/31/2021
Host Institution Award ID: G170-20-W7503
Grant Recipient: UC Davis
Region: Western
State: California
Graduate Student:
Principal Investigator:


  • Vegetables: tomatoes


  • Crop Production: irrigation, water management
  • Pest Management: cultural control, integrated pest management
  • Production Systems: organic agriculture
  • Soil Management: composting, green manures, soil analysis, soil microbiology, soil quality/health

    Proposal abstract:

    Little is understood about the interactions between and Fusarium wilt. What is the physiological basis for the deficit irrigation (DI)– plant interaction? How does the relationship between DI and disease change under variable plant and soil nutrient conditions? Can altering land management affect this relationship? In this project we will use two controlled greenhouse trials to study these interactions then collaborate with the Russell Ranch Agricultural Sustainability Institute to conduct field trials studying the effects of DI on disease development in conventional and organic systems. We aim to create disease management recommendations for growers that account for water use and nutrient management, enabling the continued use of DI. This project takes a novel systems-based approach to improve ecological and economic sustainability of tomato agroecosystems by simultaneously improving water efficiency, increasing yield, decreasing fungicide use, and improving nutrient management.

    Outcome 1: Improve the profitability of farmers by reducing losses due to Fusarium wilt

    • Reduction in detection of Fusarium wilt in tomato fields, based on number of samples submitted to the Swett Diagnostic lab in 2021 compared to the average in 2018 – 2020.
    • Increase in the annual production yields reported by the California Tomato Growers Association.

    2: Improve the environmental quality and natural resource base by reducing water and chemical use.

    • 20-50% of CTRI members reporting that water use management strategies were considered as part of an integrated disease management plan.
    • 30% of the growers using DI report awareness and preparedness in regard to disease risks
    • DPR reports indicate a reduction in fungicide applications/acre.

    3:Tailor nutrient applications by providing workshops and materials regarding the interactions between DI, disease, and nutrient applications.

    • 20-50% of CTRI growers reporting that nutrient management strategies were considered as part of a Fusarium wilt management plan.
    • 5-10% of growers using DI reporting a change in their nutrient practices rates to mitigate risks.

    Project objectives from proposal:

    Our primary goal is to take a systems-based approach to develop disease-water-nutrient co-management recommendations for tomato growers. The aim is to develop deficit irrigation methods that increase water use efficiency while improving plant nutrition and disease management. We aim to better understand and manage the interactions between deficit irrigation, Fusarium wilt, and soil health management on plant hormone production, growth and yield, and disease development by:

    1. Determining the physiological basis for deficit irrigation – plant interactions

    We will test the hypothesis that deficit irrigation alters disease dynamics through drought stress predisposition, characterized on the basis of plant hormone induction.

    1. Examining the relationship between deficit irrigation, nutrients, and Fusarium wilt development
      1. We will test the hypothesis that reductions in nutrient availability alter deficit irrigation-pathogen interactions; results will be used advise Objective 2b. This study will provide critical information on how plant nutrient affectsdeficit irrigation -plant pathogen interactions.
      2. We will test the hypothesis that targeted potassium and nitrogen amendments can be used to reduce water stress and disease predisposition associated with deficit irrigation.
    2. Examining the effect of land use management on plant nutrition and disease development under deficit irrigation
      1. We will develop baseline information on impacts of deficit irrigation on Fusarium wilt development in a field setting.
      2. We will test the hypothesis that land use management strategies which enhance plant nutrients can be used to reduce water stress and disease predisposition under deficit irrigation. The results of this study will inform the development of management recommendations.
    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.