New crop coefficients for BC hazelnut irrigation

Research Brief Publication Date: July 02, 2026
Last Updated: August 06, 2026
Researchers:

Steven T. Bristow, Thorsten Knipfer

Read the research update

New crop coefficients for BC hazelnut irrigation

Introduction

As drought and water restrictions place increasing pressure on water resources in British Columbia, reliable information on orchard water use can help support irrigation planning. UBC researchers partnered with Peak HydroMet Solutions, Pacific Agricultural Consulting Ltd., the BC Hazelnut Growers Association, and the BC Ministry of Agriculture and Food to develop the first locally derived crop coefficients (Kc) for hazelnut orchards in the Fraser Valley. Used alongside climate data from the BC AgriWeather website, these coefficients can help estimate orchard water use throughout the growing season. The project provides a locally based resource to support irrigation management and sustainable hazelnut production in British Columbia.

 

Specialized weather sensor deployed in a hazelnut field. Photo by S.T. Bristol.
This guide was developed to support the use of these newly developed hazelnut crop coefficients (Kc). It walks through the process of estimating orchard water use using BC AgriWeather data and explains how these estimates can be applied to irrigation planning and water management throughout the growing season.

About this research update

  • To learn more about the project and the lab conducting this work visit The Plant-Water Relations Lab.
  • To find evapotranspiration data for calculating irrigation, visit the BC AgriWeather website. Select your closest weather station or one that most closely resembles your orchards' conditions, and then scroll to find 'evapotranspiration' (ET) listed in green.
  • To adjust evapotranspiration data, visit the FAO ETo calculator. The FAO calculator operates on a larger software that must be downloaded and installed to a local device. Access the FAO's user manual to learn more about the calculator and how it can be used.

This document was prepared by Nisa Chavez from the BC Food Web team, with the help of Steven T. Bristow and Thorsten Knipfer from the University of British Columbia. Funding was provided in part by the governments of Canada and British Columbia through the Sustainable Canadian Agricultural Partnership, a federal-provincial-territorial initiative. Additional funding comes from the Lower Mainland Horticultural Improvement Association and NSERC Discovery.

Opinions expressed in this document are those of the author and not necessarily those of the governments of Canada and of British Columbia. The Government of Canada, the B.C. Ministry of Agriculture and Food, and its directors, agents, employees, or contractors will not be liable for any claims, damages, or losses of any kind whatsoever arising out of the use of, or reliance upon, this information.