The potentially very high yields and quality of fruit produced by intensive apple and pear planting systems make them a compelling choice for growers. That is why multi-row beds became popular in the 1980s and high-tree-density single-row systems are in vogue now.
Only a handful of growers have remained faithful to multi-row beds, however, largely because they are more difficult to manage. Single rows with a tabletop tree configuration and tree populations of more than 3,000 per hectare make spraying, weed control and picking a lot easier and can be just as productive as multi-row beds.
Intensive planting comes at a high cost, though - anything from £20,000 to £25,000/ha including trickle irrigation, which is essential. That sort of investment might make growers think twice about going intensive when a semi-intensive alternative with, say, 1,500 trees/ha costs £15,000/ha or less.
So can growers achieve a better return on capital by investing more? According to Farm Advisory Services Team managing director Tim Biddlecombe, the answer must be "Yes". "Planting more trees per hectare and getting an early high-yield build-up is a much better investment than spending less and waiting two more years to get your money back," he reckons.
"Generally the most important thing is how quickly you pay back the investment. If you spend more and get your money back quicker, it gives you a better return," he affirms.
Getting yields up to speed
Ultimately the success of any system depends on achieving high yields of class-I fruit and how quickly maximum yield can be reached. Biddlecombe says that with varieties such as Gala, intensive systems can easily produce 20 to 25 tonnes/ha in year two, only 18 months or so after planting. A maximum yield of 55 to 65t/ha is attainable after four years.
"If you can get 45t/ha of class-I fruit you should be making a reasonable return on capital," he maintains. "Last year Gala was doing 90 per cent plus class-I. If you're not getting 85 per cent or more then the economics look less favourable. There are good returns to be made from the newer apple varieties provided you're achieving high enough class-I yields."
The next question is which intensive system should growers choose - single row or multi-row beds? "It's really a bit of swings and roundabouts," says Biddlecombe. "Threeand four-row beds were favoured in the 1980s, but only a handful of growers have stuck with them.
"The main reason we advised single rows was that we felt that growth regulators would disappear (be banned)," he explains. "That would have left root pruning as the main option, but you can't use that with a bed system."
Also of help for growth control is planting the trees on ridges, an idea that Biddlecombe picked up when he visited the European fruit-growing areas and one that a few English growers are now trying. This practice, which is difficult to use in multi-row beds, is common in Italy, Belgium and Holland, and reduces growth by 10 per cent, he says.
Another advantage of single rows is that spraying is easier, especially for weed control. But it has the downside of the sprayer having to travel much farther than in multi-row beds. The ability to mechanise operations such as picking is an added advantage in view of the rising labour costs.
"Bed systems went wrong when growers allowed the trees to grow too strongly, shutting out light from lower down and reducing yield and fruit quality as a result," says Biddlecombe. "For a bed system to be successful you have to maintain the trees as individual trees, prune them to an 'A' shape and restrict their height to 6-7ft so that plenty of light gets into the bed."
However, to get the same amount of fruiting wood/ha in single-row orchards, the trees have to be several feet taller, leading to the potential problem of inadequate, poorer illumination of the lower canopy.
Getting an early heavy crop
To achieve the necessary heavy early yields and subsequent target performance from intensive single rows, high-quality leg trees with good feather development are essential. Then, after planting "and doing virtually nothing to them they will just sit there and crop", reckons Biddlecombe.
That approach has been successfully adopted for the concept apple and pear orchards at Rankin Farm, Linton, Maidstone, in Kent. They are being funded by OrchardWorld and the project run in collaboration with Sainsbury's. The grower, Tony Sunnucks, is responsible for the management of the orchards that were walked by members of the Kent SW Group NFU branches in May.
OrchardWorld technical manager Mike Jobbins explains that the objective of the project, which encompasses an intensive concept organic orchard on Peter Hall's Poultry Farm, Marden, is to bring together cutting-edge techniques to substantially increase the yield of class-I fruit. The 1ha Rankin's concept apple orchard, planted in spring 2006, is well on the way to doing that. An adjacent 1ha concept pear orchard was planted in spring 2010 and a similar area will go in next spring.
Jobbins points out that higher average yields than England's are produced in the Loire Valley in France and in Holland. "Geographically, we are between the two and so, in some ways, we are better off and should be able to match these yields by employing the best technology, including pest and disease computer prediction models to ensure accurate, cost-effective spray timings.
"In a way the organic orchard is more interesting because it's a proving ground for the use of fewer (chemical) inputs," he says. "It's enabling us to look at alternative ideas and, while we are not advocating that everyone should be organic, we are finding that there is a middle ground between conventional and organic production and that's probably where the industry will end up."
Rankin's apple orchard, on a virgin grassland site, comprises about 1,000 trees each of Gala, Braeburn and Cox and 50 each of Bramley's Seedling, Rubens, Estivale, Junami and Pinova, all on M9 rootstock. The well-feathered leg trees were planted directly into the soil apart from a few that went into compost plus slow-release fertiliser. The latter were noticeably more vigorous in their first few years.
The Cox is spaced at 1m by 3.25m and the others are 0.8m by 3.25m. They are tied to hardwood canes that are supported by a top wire attached to 2.5m tall by 9cm square concrete straining posts spaced at 10m intervals.
Galvanised steel cross-arms are fixed horizontally to the posts at about 45cm above ground level. Wires are attached to the arms along the row length to support the lower branches of Braeburn in particular that otherwise would droop to the ground under the weight of fruit.
To help keep the trickle irrigation lines clean they are clipped to wires fixed to the posts 30cm above the ground. Because there is no natural water source, mains water has to be used for irrigation. The trees are fitted with wire-netting rabbit guards.
Growth control measures
At planting the feathers were tipped and the leaders left intact. Since then just the leaders have been tipped to maintain a tree height of about 3m and the stronger branches removed to produce a balanced lower tabletop and keep the trees "A" shaped. This configuration helps ensure the best possible light penetration throughout the trees' height.
For growth control Sunnucks, who grows 45ha of semi-intensive apples and pears and 8ha of plums, has relied on root pruning one side of each row one year and the other side the next. Cox has been done every year since 2008 and the other varieties only in 2008 and 2009. Since then their vigour has been controlled by crop load. The operation has helped keep Cox's growth within bounds, says Sunnucks.
Yield build-up has been roughly as predicted and better than that for less intensive systems. By year three (2009) the average yield for Braeburn and Gala was 30t/ha and in 2010 it was 40t/ha. This year 60t/ha is predicted. In all years the class-I grade-out has been more than 90 per cent. Cox's yield has been 10 to 15t/ha below that of the other varieties.
The pear trees, spaced at 1m by 3.25m, are on quince C rootstock and have the same support system as the apples. The varieties include Conference, Verdi, Elliot, Delsavor and Delsan. Sainsbury's considers that Delsan has very good sales potential and has signed an exclusive deal with its French breeder Delbard for the UK and European marketing rights, says Jobbins.
"It has an October to January season, picking in late September and early October for immediate sale," he adds. "It's very sweet and juicy with smooth flesh and aromatic flavour. We plan to plant 90,000 Delsan trees in the next eight or nine years."