Trellis-growing is being explored as a potential game-changer for the New Zealand citrus industry following damage caused by Cyclone Gabrielle to a Gisborne orchard. The cyclone affected over 700 new seedless Eureka lemon trees, prompting growers to consider alternative growing methods. Trellis-growing involves training citrus trees to grow horizontally along a wire trellis, making them more manageable for pruning, pest control, and harvesting. This method is expected to offer various benefits, including increased yield, earlier fruiting, improved fruit quality, and the potential for robotic harvesting.
The initiative was sparked when Tam and Dan Jex-Blake, orchardists in Manutuke, Gisborne, sought solutions to protect their citrus and Rockit apples from future cyclone-related damage. Matt Carter, new variety development manager at First Fresh, was inspired by trials of trellis systems for citrus in Australia, prompting discussions on its feasibility in New Zealand. The concept involves constructing a trellis structure that elevates young trees and facilitates drainage, preventing them from getting wet feet during adverse weather conditions.
The Gisborne growers, in collaboration with First Fresh, embarked on a research trip to the United States in May to study trellis-growing orchards in California's San Joaquin Valley. The visit included exploring different techniques and observing various trellis-growing systems, with a focus on dekopon (a variety of satsuma orange) and lemon orchards. The team sought insights into the potential advantages of trellis-growing, such as increased light exposure, enhanced fruit production, improved orchard management, and the prospect of robotic harvesting.
Upon returning to New Zealand, the Jex-Blakes implemented a trellis structure at their orchard, incorporating the best practices observed during their research trip. The installation, completed by early September, involved planting the young trees on mounds for additional elevation, mitigating the risk of silt damage in the event of another cyclone. The combination of trellis-growing and planting on mounds is expected to enhance protection, yield, and overall orchard efficiency.
This trellis-growing initiative is believed to be New Zealand's first greenfield commercial citrus planting using this method. The approach aims to provide support and protection for citrus trees, create optimal growing conditions, and explore the potential for robotic harvesting. The trellis system, by opening canopies to more light, is anticipated to lead to increased fruit production and make orchard management more streamlined. Additionally, the method allows for intensification, with wider rows accommodating higher plant density, potentially offsetting associated costs.
While the initiative is currently viewed as a trial, the Jex-Blakes express confidence in its success and see trellis-growing as a long-term strategy for the future of citrus cultivation in New Zealand. The combination of resilience against adverse weather events, improved efficiency, and potential yield increases positions trellis-growing as a promising innovation for the country's citrus industry.
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