Moving to methods of growing soft-fruit and using products that are more environmentally friendly can, with patience, secure a more sustainable future once the natural balance has been re-established.
With over 30 years of growing strawberries to look back on, Alastair Brooks of Langdon Manor Farm near Faversham, Kent, has been delighted with his farm’s results in 2018. “It had become clear that there were no chemical options available to control some pests of long-season strawberry and raspberry crops, where flowering and fruiting coincide, so we wanted to go for a zero-insecticide policy that would also protect pollinators”. There were no chemical options for pests like potato aphid and western flower thrips (WFT), so this meant using introduced predators such as predatory wasps for aphid control, and a soil-based predatory mite Hypoaspis miles, followed by introductions of Amblyseius cucumerisfor WFT. Phytoselius persimilis has also been introduced for the control of two-spotted spider mite. All applications of biological control are done on a programmed approach that allows populations to establish ahead of the pest populations.
Five years ago, Gerry Scallan joined Langdon Manor Farm as farm manager and carries out the plant protection programme. Both he and Alastair admit that the first year of this strategy was shockingly expensive, but it becomes progressively cheaper in subsequent years as you start to create a balance. From their observations, there is now a ‘tame’ indigenous population of Orius predators on the farm and pests like blossom weevil and capsids have ceased to be a problem. Gerry says, “Now the tunnels are full of hoverflies and spiders, it’s not a desert anymore.” Gerry stresses that this approach is a little more expensive and requires a lot more management, but he and Alastair consider that they get a higher percentage of Class 1 fruit. Gerry says, “Strawberry crops look better – the leaves are glossier”.
Relying on beneficial insects has meant that only products safe for biocontrol can be used. Two products from Omex have proved useful in improving fruit quality, namely Kelpak and CalMax Ultra. Fruit firmness was an issue with larger fruiting varieties like Amesti, and Gerry was looking for an environmentally friendly solution. Kelpak is an organic biostimulant containing a concentrated extract of the kelp species Ecklonia maximaand CalMax Ultra contains calcium in conjunction with a ‘pump primer’ that ensures that the calcium can be actively transported into plant cells. Biostimulants are especially useful in encouraging plants to develop early root systems, so they are better able to access water and nutrients later in the growth cycle. Biostimulants are different from nutritional fertilisers as they may also contain a mixture of things such as micro-organisms, trace elements, enzymes, plant hormones and seaweed extracts that enhance the performance of the plant.
“CalMax Ultra helps calcium to move around the plant and Kelpak has two functions: one, to get calcium into the fruit to make it firmer, and secondly, it helps development of the pollen tube, leading to more uniform berry size and shape. Now we see very few big ugly fruits,” explains Gerry. Spray applications of Kelpak and CalMax Ultra have solved the fruit quality problem, “I now have a happy packhouse manager” he adds. Alastair says he can’t remember the last rejection for wet bruising. Gerry continues, “Since we started using Kelpak and CalMax Ultra from flowering onwards, we’ve noticed Class 1 fruit has increased a lot. Starting four years ago, we’ve been adding a bit more each year and now we wouldn’t be without them on strawberry production.”
A challenging 2018 season provides lessons for 2019
Langdon Manor Farm is an early site, with the variety Flair grown in bags on beds on the ground instead of table-tops, giving seven to 10 days earlier production. The late winter brought the ‘Beast from the East’ which meant that in the farm weather station temperatures as low as minus 17C were recorded on 27 February. Despite the cold weather, the season started on 20 April, so Gerry says, “The farm was producing when very few others had fruit, and fruit quality was very good in June, but it got harder as the season progressed. The prolonged hot spell in July caused issues with thermo-dormancy, which led to poor yields of everbearers in September and October.
The June-bearer Malling™ Centenary was a success, with better plant quality leading to fewer problems and Gerry was pleased with the 30 tonnes/ha yield which was “better than expected”. As a Berry Gardens member, the farm grows Driscoll Premium varieties like Elizabeth. Gerry describes Elizabeth as tasting brilliant with a real sugar rush when you eat it straight off the plant. With everbearers, the farm mostly grows Amesti but was trialling new Driscoll varieties Zara and Katrina in 2018 and found them less affected by thermo-dormancy, so will grow more in 2019.
The major issue for soft-fruit growers continues to be labour, and this is reflected in plans for the future. As Alastair says, “It’s all about labour, no-one wants to be bending over anymore, so all crops will be on table-tops. Keep people happy and you’ll have returnees”. The early crop of Flair will be grown in pots on the ground until after flowering under lowered tunnels, then, as the tunnels are raised on telescopic legs, the plants will be lifted onto table-tops for ease of picking. Improved productivity has been the answer to a 300 per cent increase in labour costs. “We use the same number of people to produce twice as much fruit as we did five years ago”, says Alastair. Innovations, like roller doors on the tunnels, have saved labour as you used to need a team of four to help open and close doors during spray rounds. In general, there is a substitution of labour for capital. This is driving the move to all table-top production, breeding larger easy-to-pick berries, and annual planting systems, as these are easier to harvest.
Alastair is spending even more on facilities for pickers, as the focus is on looking after people better. “The biggest crisis is when the internet goes down,” he jokes. “We get valuable feedback via mid-season and exit questionnaires, which we act on. We have had to adjust pay rates to make it more attractive and at present figures for 2019 show a nearly 80% returnee rate which is better than 2018.”
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