Deficit irrigation, recycled water and plant disease

As water supplies decline, agricultural users adapt by shifting to lower quality supplies and reuse. Thus, water treatment and reuse is a critical knowledge area because we do not completely understand how to resolve many grower-identified issues that currently limit use of recycled water for irrigation purposes.

These major issues include:

(1) potential contamination of recycled water sources with pathogens, pesticides (e.g. herbicides, fungicides, plant growth regulators), and nutrients,

(2) irrigation and agrichemical scheduling to ensure economic quality while minimizing agrichemical loss, and

(3) cost-benefit analyses of recycled water sources and treatment technologies (TTs) to facilitate their use

We have formed a multidisciplinary team to address these emerging issues; for more information on concurrent research projects, we welcome you to visit our website:

The Swett lab forms the pathogen team, together with PI’s Jennifer Parke (Oregon State) and Sarah White (Clemson). We collaborate with growers and extension faculty to address major disease management issues related to reduction and recycling of water.


Projects include:

  • Assessing effects of deficit irrigation on oomycete pathogens in nursery and greenhouse production: informing water reduction practices through risk assessment
  • Detecting unrecognized oomycete pathogen diversity in irrigation ponds, and improving efficacy of water treatment strategies
  • Can deficit irrigation suppress spread of Phytophthora and Pythium root rot pathogens in recycled water?