The Univesity of Reading and Soft Fruit Technology Group.

The Soft Fruit Technology Group was started by Nick Battey in 1997. James Carew joined the group a year later having completed a PhD on the control of raspberry growth and cropping. Advanced Marketing Services LTD co-funds the work of the Soft Fruit technology Group at Reading University with Fast, Hargreaves Plants and Field.

The majority of the UK strawberry industry is connected to the Soft Fruit Technology Group and because of this the group is uniquely placed to respond to the needs of a rapidly developing industry. The aim of the work remains to carry out specific experiments geared towards developing future production systems. Provision of technical information to the user base then becomes a priority.

The group has access to impressive resources, both in terms of facilities and staff. Because it is part of Reading University, the group is also involved in training BSc,MSc and PhD students for future careers in horticulture and these provide a cost effective way of increasing research output. The flexibility and cost effectiveness this creates has enabled vertain projects to be turn round within 67-9 months.

Over the last four years the group has completed around 24 projects and in thsi article some of the more recent ones are highlighted to show the range undertaken and their relevance to the industry.

Controlling ever bearer cropping
The last few years has seen a considerable improvement in the quality of everbearers being released from both Uk and overseas breeding propgrams. However it seems likely that because of significant gaps in the knowledge of how cropping is controlled in everbearers, potential for optimmisation of production exists.

Last year the SFTG emabrked upon a seies of experiments designed to begin this process by investigating the effects of chilling and nitrogen on tge growth of everbearers. To ensure the results are applicable to the industry, a table-top system was set up within a Spanish tunnel on which the plants are being grown. Results can therefore be taken from Reading and applied directly on commercial farms.

Even though only two seasons work have been completed, significant effects on growth and cropping have been observed already. Both the chilling and nitrogen trials demonstrated even more marked differences than had been predicted and go a long way to explaining what we see in commercial production. The second year trials have confirmed data from the first year and so we now have a firm basis for making specific recommendations.

- Winter chilling has been shown to clearly influence the timing of cropping by up to a month
- Plant growth and habit, post field planting, reflects the degree of winter chill.
- Optimum levels of nitrogen have been determined
- Cultivar differences have been shown to be significant

Thsi work will allow us to spread the peaks of everbearer production, improve quality, optimise yield whilst minimising use of N fetiliser.

Effect of light on raspberries
An opportunity for manipulating the growth of raspberries by varying light quantity and quality exists. This was the conclusion from a three year project recently completed by a PhD student at Reading.

The effect of a range of plastics supplied by Visqueen on "Glen Ample", "Joan Squire" and "Autumn Bliss", was tested. Some of these reduced summer heat, some altered light wavelengths and some scattered light so that it would penetrate deeper into the canopy. Each had a different effect.

- Timing of cropping could be manipulated by three weeks
- vegetative growth and cane archtecture could be altered
- Significant effects on yield were also observed

Optimisation of waiting bed "Elsanta" establishment
"Elsanta" is now available in a bewildernig array of plant sizes. With each, though, the cost/benefit balance is critical and so the industry has developed systems of production to optimise yields. One of the factors in which the SFTG has been interested is the use of low-volume sprinkle irrigation. This has two effects

- reduction of plant temperature
- reduction on the rate of transpiration

Both have the effect of reducing plant stress and everyone recognises the benefits of sprinkle irrigation. The problem is that there is significant disagreement in the way that this should be applied. Timings used vary from every 15 minutes to once a day and the amount of water applied varies just as much.

The SFTG was commissioned by HDC to determine the optimum way of applying sprinkle irrigation. To do this Heathlands Farm set up strawberry beds at Reading for the SFTG giving, yet again, a completely commercial system in which to grow the plants, without which the results would have been meaningless. Instead we found that

- Yield varied by 50% dependng on misting treatment
- Altered susceptibility to mildew was clearly visible
- Application timing and duration was crucial.

Conclusion
In an article of this type, a complete description of five years work is impossible. Instead a few recent projects have been highlighted. If you would like further information on how to become nvolved with the SFTG, please contact Nick Battey or James Carew at the Soft Fruit Technology Group, Department of Horticulture, The University of Reading, Reading RG6 6As. Tel 0118 931 6439. fax 0118 975 0630 or email j.g.carewreading.ac.uk

Autumn 2002