Will climate change expand Hass avocado growing areas?

October 13, 2026

Climate change could alter the areas where avocados can be grown. In New Zealand, projections often point to the Hass avocado as one of the crops that would gain suitable acreage with rising temperatures. This is according to the study “ Irrigation, Water Deficit and Crop Load Effects on 'Hass' Avocado Fruit Size Under New Zealand Growing Conditions,” published in Horticulturae, which reviews these projections in light of water availability.

This would be possible by reducing the limitations imposed by frost and low spring temperatures. However, the research warns that the projections do not take into account irrigation requirements, a factor that could hinder expansion.

New Zealand, which already has commercial avocado production, presents a unique case. Its relatively cool and humid conditions allow many orchards to operate without irrigation. However, the stronger and more intense summer droughts projected for avocado-growing regions pose new challenges for crop management.

The study, led by Teruko Kaneko, Nick Gould, David Campbell, and Michael John Clearwater, addresses issues such as water availability and fruit growth. Their results show that even brief periods of water deficit can affect avocado size under relatively moderate climatic conditions.

Thermal conditions and water availability: a delicate balance

According to researchers, New Zealand has one of the coolest climates in the world for commercial avocado production. The low and unstable spring temperatures can disrupt the fruiting process, contributing to uneven fruit set and prolonging fruit development.

Assessments that identify a potential increase in crop yields with higher temperatures rely on this eventual reduction of thermal constraints. However, a warming of the environment does not, in itself, guarantee sufficient conditions to sustain production.

The study indicates that droughts brought on by increased heat could increase both the demand for water for agricultural use and the pressure on its availability. This is why access to irrigation appears as a potential limitation to the expansion of avocado cultivation in the country.

The research did not directly assess the effect of future temperatures nor did it map new production areas. Its objective was to measure how water deficits affect fruit growth, yield, and quality, to provide information for irrigation management in a more variable climate.

A three-season trial in New Zealand

The researchers worked in a commercial orchard in Omokoroa, in the Bay of Plenty, during the 2016–2017, 2017–2018, and 2018–2019 seasons. Twenty-four adult Hass trees grafted onto Zutano seed rootstocks were selected and distributed between treatments with and without irrigation.

Although rainfall varied between seasons, each summer included a two- to three-week dry spell. This reduced soil moisture for trees that depended solely on rainfall.

In the second season, which had a heavier fruit load, the dry period coincided with an early stage in fruit development. Analyzing the results, and considering the differences in fruit load between trees, the research team found that avocados from the non-irrigated treatment weighed, on average, 26.4 grams less at harvest, an approximate reduction of 10%.

This difference corresponds to the individual weight of the fruit. The study did not detect a significant effect of irrigation on total yield per tree or on the dry matter content of the avocado.

Fruit load and its effect on water analysis

One of the main difficulties in the analysis was the variability in production between trees and seasons. The heavier the crop load, the lighter the avocados tended to be. This factor could mask the weight differences associated with water supply.

Therefore, the effect of the absence of irrigation on the weight of the avocado became evident after incorporating the fruit load into the analysis.

During the third season, extremely low fruit set was recorded, resulting in no measurable harvest. The authors believe that unusually cold spring conditions likely contributed to this outcome, although measurements of the trees' water status continued.

These facts demonstrate the need to consider not only the climate, but also the availability of water and the reproductive variability of the avocado when interpreting its productive performance.

Irrigation as an essential condition for future expansion

The study concludes that irrigation deserves special attention even under current climate conditions in New Zealand. This is because its importance could increase if the risk of summer droughts grows, especially during the early stages of fruit development.

The report also highlights the need for further research to compare irrigation requirements between high and low production seasons. Management recommendations should consider soil conditions, tree health, and fruit load.

While this case allows us to address the question of a possible expansion of avocado-growing areas, it does not demonstrate that climate change alone will generate new production sites. It is crucial to consider that temperature-based projections must take into account water constraints.

Even if an area is potentially more suitable from a thermal standpoint, it may face greater difficulties in supplying water to the orchards simultaneously. These factors limit the potential for sustainable commercial production.