A cucumber-grower walk held earlier this month by project host David Schellingerhout at Glen Avon Growers, Hull, showed the system in production and attracted representation from 18 UK cucumber growers. Organisers said a better evaluation of the system will be made once the crop has finished at the end of the season. While initial findings are proving positive, current market conditions - low product price and high production costs - could prevent growers making the initial investment needed to get the system up and running.
Project leader, crop consultant Rob Jacobson, told Grower: "A lot of other issues will affect the adoption of the system - energy and fertiliser costs have rocketed this year, while prices obtained for the crops have been rock bottom. We will have to wait until the end of the season - some time in October - to evaluate the system fully."
The high-wire system involves training a single stem up a vertical string to a horizontal support wire positioned 3.8m-4.2m above ground. As the plant approaches the wire it is layered so that only the most recent 2.8m-3.2m of growth is ever vertical. The younger and most productive leaves are then continually positioned to maximise light interception - a key factor in obtaining higher yields. The current cordon system used by most UK growers sees the main growing points removed to allow two lateral shoots to cascade downwards to a length of about 1m, where light levels are not optimum.
The project stems from a previous study (PC 201) that evaluated supplementary lighting use alongside the high-wire system for year-round growing. Despite optimum yields of 315 cucumbers per square metre (currently 125 with normal cropping), additional lighting costs lighting made the system unviable.
Taking stock of developments at week 33 (mid-August) Jacobson noted that the crop was 12 cucumbers per square metre ahead of normal crop production. He noted that while energy use as a whole was a little higher than normal production methods, when viewed as energy used per cucumber the use was slightly better.
While labour use at harvest is at similar levels to standard crops, at week 33, 60 per cent more labour had been used in training the plants to the high-wire system.
A full assessment will be made in October at season's end, with an HDC report likely to be published in January 2009.