GEN Shutterstock_two red shiny delicious apples hanging from a tree branch in an apple orchard

Switching from traditional orchard systems to fruit-wall orchards could make mechanising the pruning of apple trees easier and cheaper for growers, AHDB Horticulture research has found.

Post-Brexit uncertainties about the fruit industry’s ability to source seasonal workers, combined with an increase in labour costs, have brought the industry’s reliance on human labour into sharp focus. More than ever, growers are exploring ways of mitigating the industry’s reliance on manual workers.

Modern intensive orchards are already simpler and easier to prune than traditionally planted ones but it can still take between 25 and 40 hours of labour per hectare.

In fruit-wall orchards, mechanical pruning work rates vary between 1.5 and 2.5 hours per hectare, so even though some hand-pruning will be needed, there is potential to save around £3,000 per hectare over an orchard’s 15-year life.

Mark Holden of topfruit grower AdrianScripps, who is an industry representative of the project, said: “The cost of labour is inevitability increasing due to the rises in the minimum wage. Also, there is a potential shortage of a quality workforce in the future. Therefore, I am keen to explore how we can get the best from mechanisation.

“Another key target is improving the consistency and quality of the fruit from tree to tree in the orchards. Mechanical pruning was identified as, potentially, one way to achieve both these goals.”

AHDB Horticulture has spent the last four years investigating the tree types and pruning regimes most suitable for use in a fruit-wall orchard in the UK in two projects.

Recommendations have been generated from one of the projects about when trees should be pruned in fruit-wall orchards. These include:

- Delaying mechanical pruning to the nine or 12-leaf stage in strongly growing orchards and where tree vigour control is important

- Pruning at the nine-leaf stage where limited regrowth and improved fruit bud formation are required

- Pruning at pink bud to increase fruit size and sugar content where trees are not vigorous and in balance. This will encourage more growth however.

Commenting on the results of the study, Holden said: “The results have demonstrated that there is a place for mechanical pruning, but as a complement to, and not a substitute for, hand pruning. The decisions on mechanical pruning must also reflect the growing season and will need to be targeted on certain varieties and appropriate orchards to have the most benefit.”

An update from the research projects will be presented at the AHDB/EMR Association Tree Fruit Conference, which takes place on 28 February at NIAB EMR’s research centre in Kent. Growers can book a place here.