Developing a Pesticide Resistance Management regime utilizing soluble silicon fertilizer

Project Overview

Project Type: Research and Education
Funds awarded in 2024: $348,523.00
Projected End Date: 03/31/2027
Grant Recipient: University of Hawaii
Region: Western
State: Hawaii
Principal Investigator:
Dr. Joanna Bloese
University of Hawaii
Dr. Teresita Amore
University of Hawaii at Manoa
Russell Galanti
University of Hawaii at Manoa
Hannah Lutgen
University of Hawaii at Manoa
Dr. Stuart Nakamoto
U. of Hawaii Manoa, Human Nutrition, Food, and Animal Sciences
Dr. Alberto Ricordi
University of Hawaii at Manoa


  • Additional Plants: ornamentals


  • Pest Management: integrated pest management

    Proposal abstract:

    PROBLEM & RESEARCH: Growers understand that the sole use
    of chemicals to control insect pests is not a sustainable
    long-term solution (Seal et al., 2013), and creates high
    selective pressure for pest resistance. Hawaii Floriculture and
    Nursery (HFN) industries’ reliance on chemical management stems
    from the wide range of invasive pests they encounter due to the
    diverse crops grown by this industry.

    Silicon-medicated plant resistance to herbivorous insects has
    been well documented over the past two decades. This project will
    expand upon research by Bloese et. al. 2023 (In Review) that
    found significant benefits of Si to reduce various invasive
    invertebrates and fungal pathogens in nursery crops.

    This project will conduct applied research through on-farm trials
    to quantify reduction in pest and disease densities, yield
    differentials, and changes in plant physiology among four Si
    augmented pesticide regimes across four species of ornamental
    crops. Research results will inform a resistance management
    strategy which will reduce growers’ reliance on chemical
    controls, reduce the high selective pressure for resistance, and
    improve overall sustainability of the industry.


    SIGNIFICANCE & OUTCOMES: Hawai’i’s potted plants and cut flowers
    represent approximately 45% (almost $35 million) of a $77.6
    million HFN industry in 2017 (HDOA Annual Summary, 2018).
    Additionally, HFN industries have a rich cultural and
    environmental significance. They produce flowers and foliage for
    lei and hula, as well as many native plants. Minimizing pesticide
    use for this industry will: (a) protect the biosecurity of native
    plants, (b) increase industry profitability, (c) increase the
    health and safety of farm systems and workers, and (d) reduce the
    selective pressure for resistance by invasive pests.


    EDUCATION & DISSEMINATION OF RESULTS: Outreach and education
    objectives will incorporate research results in the development
    of a Si enhanced pesticide resistance management program and
    updated Best Management Practices (BMPs). The active
    participation of stakeholders in the project enhances ease of
    dissemination of project results through Field Days, extension
    publications, webinars, conferences and peer-reviewed
    publications. These modes of communication will ensure that the
    project findings reach and benefit a broad audience, including
    growers, researchers, industry stakeholders, and policymakers. A
    series of questionnaires and surveys will evaluate the long-term
    adoption of BMPs by growers.


    Logic Model for Silicon-Enhanced Pest






    Research Expertise

    On-Farm Trials, Data collection, Analysis

    Quantified Pest Reduction

    · Reduced selective pressure

    ·  Improved long-term sustainable pest management

    Transdisciplinary Team (Growers, Educators, Researchers)

    On-Farm Trials, Data Collection, Analysis

    Crop Health & Yield Insights

    ·  Improved plant health and production; reduction
    of agricultural inputs

    · More resilient agriculture system to supply chain


    Research, Analysis

    Physiological Changes

    · Improved Si application methodology for enhanced

    · Improved industry sustainability; Improved worker

    Peer to Peer Education & Outreach

    Strategy Development & Outreach

    Resistance Management Strategy

    · Reduced reliance on chemical controls and reduced
    pesticide usage.

    ·  Reduced environmental Impact; Improved
    profitability; and economic benefits

    This logic model illustrates the flow from resources and actions
    to the anticipated results and eventual broader impacts of the
    research and education project.

    Project objectives from proposal:


    Objective 1: Conduct five multi-island on-farm trials to
    evaluate the efficacy of four Si-augmented pesticide regimes
    across key ornamental crops in Hawaii. Efficacy of the four
    pesticide + Si-augmented treatment groups will be determined
    through the following sub-objectives. (Specific treatment
    levels are detailed in Research Plan section of the

    Subobjective 1(a): Determine yield differential and flower
    quality among Si treatment groups.

    Subobjective 1(b): Quantify pest composition and prevalence among
    Si treatment groups.

    Subobjective 1 (c): Quantify disease composition and prevalence
    among Si treatment groups.


    Objective 2: Assess changes in plant physiology to better
    understand mechanisms of plant protection by Si to maximize
    resource efficiency and optimize application. This will be
    achieved through the following subobjectives. 

    Subobjective 2(a): Measure canopy size, stalk number or root mass
    to quantify gross plant growth across Si treatment groups.

    Subobjective 2(b): Quantify Si, nutrient, and chlorophyll content
    in plant tissue among Si treatment groups. 

    Subobjective 2(c): Image leaf surfaces and tissue sections among
    treatments and crops to quantify stomata and trichome number and
    document organ size and structure, respectively, to evaluate
    possible morphological markers for physiological effects of


    Objective 3. Conduct cost-benefit analyses to assess the
    economic viability of using Si as an amendment in pesticide
    management regimes.



    Our Education Plan is three-fold.

    Objective 1: Develop Best Management Practices (BMPs) for
    pesticide resistance management in nursery crops that are
    practical, effective, and adopted by stakeholders.

    Objective 2: Promote long-term sustainability of BMP
    adoption through active learning and student-centered education
    outreach activities.

    Objective 3: Reassess adoptability of BMPs by addressing
    concerns and misconceptions related to BMPs, providing
    information to mitigate perceived risks, as well as develop
    strategies for scaling up BMP adoption through
    grower-extension-researcher collaborations.


    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.