A new digital tool has been released to help Kiwi growers and farmers track the impacts of transpiration on their crops and evaporation and rainfall on their land so they can make more informed decisions on when to irrigate

Available on MetWatch and many of the Weather & Disease Portals created by HortPlus for growers in different industries, the new Evapotranspiration Tool simplifies data on plant water usage, evaporation and rainfall into an easy to understand display.

HortPlus director Mike Barley said his team had worked closely with an advisory panel of leading New Zealand researchers and growers to develop the tool and was thrilled to make it available before the warmest months arrived.

“The shift from a La Niña to El Niño weather pattern in the Pacific will make this summer more challenging than many others in recent years. This tool will add to the growing technology toolkit of Kiwi growers and farmers and support their decision making.”

The Evapotranspiration Tool takes account of factors including rainfall, wind, humidity, temperature, sunlight and the type of crop being grown. By modelling evapotranspiration with data from weather stations across New Zealand, the tool can generate localised historic and forecast evapotranspiration information to provide insights for growers and assist in their day to day irrigation decision making.

“The beauty of this resource is in its simplicity. It’s a great education resource but it will also be useful for those who are working out in the field, whether they are an orchardist trying to work out the transpiration rate for their fruit trees or a farmer making decisions on when to irrigate their pasture,” Barley said.

The Evapotranspiration Tool can be accessed through a MetWatch subscription or via HortPlus Weather & Disease Portals available on the websites of NZ Apples & Pears, Summerfruit NZ, Onions NZ, Vegetables NZ, Foundation of Arable Research and Plant & Food Research.

Once logged in, growers can use the tool by selecting the ‘Daily ET & Rainfall’ option under the ‘Irrigation’ dropdown menu.