Horticulture Newsletter - August 2010

Return to Ghana – 2 the exotics

Ghana has enjoyed an influx of crops and amenity plants which have transformed its economy and the streets of its cities and towns.

Where should I start in the tale of exotic plants that have affected the economy and amenity of a country which gained its independence in 1957. Two economic species stand out: cocoa (Theobroma cacao) and groundnuts (Arachis villosulicarpa). Both originate in South America; both were introduced in colonial times. This isn't the place to chart the successes and failures of schemes to enhance the economy of what was once a West African colony. Suffice it to say that cocoa is still a major economic earner for Ghana.

Back in the 1950s, wherever you went, you could buy a poke of roasted groundnuts, fresh from the fire. They smelled and tasted delicious.

Plenty of other plants were imported into Ghana and other tropical countries – the edible ones include tomatoes, chilis, cassava and maize from South America, and aubergines from Asia. It amazes me that these crops were so recently introduced. For us Europeans, how did we manage without tomatoes? And for Ghanaians, how did they spice up the sauce that flavoured their yams?

There are many exotic ornamental plants that decorate the streets and gardens of Ghana. Two South American families have been really successful – Apocynaceae and Bignoniaceae. I grew up with sublimely scented frangipanis (Plumeria sp. top photo by Renesis) in our garden, and hedges of yellow oleander (Thevetia peruviana, middle photo by G.M. Garg). When I returned recently to Kintampo in central Ghana, the self-same frangipani tree that I last saw in 1954 was still there. Its flowers remind me of aeroplane propellers; if you grow periwinkles (Vinca spp – same family), you'll know what I mean. The tree in our old compound that I'd hoped to see – Spathodea campanulata: to me, the Tulip Tree; to Elspeth Huxley, the Flame of the Forest, was gone.

Walking round the major towns – Cape Coast and Accra – you'll encounter the usual suspects in amenity plantings. Plenty of scarlet Hibiscus; Acacia; Bougainvillea and flamboyant (Delonix regia - lower photo by Stephen Lea). Two trees that thrive here are the Norfolk Island Pine (Araucaria heterophylla - I had no idea it was related to the Monkey Puzzle; just loved it at Manly, north of Sydney) and a fastigiate version of the Persian lilac (Melia azedarach), which works well as a columnar street tree.

Margaret Waddy
SCI Horticulture Group

Fruit Focus

Farm tours are always popular with visitors at Fruit Focus at East Malling Research. This year, amongst other research projects, a five-year HortLink project (HL0191) on minimising pesticide residues in strawberry through integrated pest, disease and environmental crop management was on show. Professor Jerry Cross, who leads the team, and Michelle Fountain were able to tell growers that excellent progress has been made with some important findings and implications for pest and disease management in strawberry.

The overall aim of the project is to develop alternative, sustainable, non-pesticidal methods for managing Botrytis, powdery mildew, black spot, aphids, blossom weevil and capsid bugs on strawberries so greatly reducing (by >50%) pesticide use and eliminating the occurrence of reportable pesticide residues in harvested fruit.

The project has shown, for instance, that infection of fruit and flowers by Botrytis on June-bearer crops covered early in the season is minimal suggesting that Botrytis fungicides may not be necessary in this situation. Where treatment does become necessary, researchers have shown that honey and bumble bees can effectively carry a specially formulated Botrytis biocontrol product to strawberry flowers. This may provide an efficient way of treating crops.

Sweet alyssum (Pictured right, photo by Pharaoh Hound) has been shown to be an excellent 'trap crop' for European tarnished plant bug (ETPB). It can readily be grown in the leg rows of Spanish tunnel protected crops. Regular use of tractor mounted crop vacuuming, known as 'bug vaccing', in July and August has also been shown to greatly reduce ETPB populations. The combined use of the two control approaches is being evaluated in a large scale field trial.

A 'supertrap' for strawberry blossom weevil has been developed which combines the weevil's sex aggregation pheromone, a volatile from wild strawberry flowers, a white visual colour and a robust and effective trap design. These 'supertraps' are currently being evaluated for monitoring the weevil and control by mass trapping.

Fruit Focus has always been the ideal event for growers looking to discover new innovations and initiatives to enable them to be more productive and profitable. On the Agrovista stand, growers could see their new Fruitwise HyGro vertical growing system which effectively utilises the vertical space in the growing area to increase plant density and production whilst being environmentally kind. This is a key benefit allowing growers to optimise land use with fewer tunnels needed to grow the same amount of crop. Fewer tunnels will cause less planning headaches but are also a way of continuing to use tunnels on an approved site where the soil needs sterilising to continue cropping but finding new land to put up 'temporary tunnels' may be increasingly difficult.

The Fruitwise HyGro vertical growing system consists of columns of coir based, wagon-wheel shaped planting cells. The perforated central column is made up of injection-moulded segments that lock together. As the cells are independently irrigated and drained there is no chance of transmission of water borne disease. The system can be managed for run-off to waste or for recirculation unlike table tops where run-off from each bag drains to waste on the tunnel floor. It offers significant water saving (as little as four times less water than peat bags – on average 50 to 60ml per day per plant). Agrovista have trials of the Fruitwise system at several large UK strawberry growers and there is considerable interest and more development work going on in Holland and Germany.

Working demos, new machinery and growing technology were prevalent at this year's Fruit Focus Show. Machinery demonstrations proved popular again. Soft and top fruit growers, as well as vineyard owners needing a compact but heavy-duty tractor, were shown a new version of the Rex model launched by Landini at the show. A tighter-steering front drive axle for the Rex 'F' further improves the tractor's agility.

This year those looking to make green advances were also catered for thanks to the appearance of bpi.recycled products. Together, the two divisions of British Polythene Industries (BPI) plc promoted their ability to help growers operate in a more eco-sensitive way by keeping reusable polythene in circulation - and out of landfill. Currently, bpi.recycled products which ranks as Europe's largest recycler of waste polythene, reprocesses over 70,000 tonnes of waste polythene each year, including scrap from unwanted polytunnels and crop covers. The waste is used to create outdoor furniture, building supplies, refuse sacks and many other products.

Joanna Wood
SCI Horticulture Group

Plants of the Month

The Clock Vine - Thunbergia mysorensis, Acanthaceae

This beautiful climber is native to the area around Mysore, a city in Karnataka state, India. It is a rampant grower but produces these attractive pendulous racemes of red and yellow flowers throughout the year. It must be kept frost free and flowers more prolifically if kept warmer. Most plants in the Acanthaceae are tropical herbs, shrubs or vines with only a few found in the temperate regions. One of the species most familiar to gardeners in the UK is bears breeches (Acanthus mollis). Typically Acanthaceae flowers have a colourful bract around each flower. The flowers of the clock vine do indeed have a red coloured bract but the very colourful part is the corolla of the flower which consists of five fused petals. There are four stamens surrounding the style.

Medicinal Plant of the Month

Thorn Apple, Datura stramonium, Solanaceae

Also known as Jimson weed amongst many other common names, Datura stramonium, is an annual herbaceous plant in the Solanaceae, the potato and tomato family. Along with many other plants in the potato family the thorn apple contains a number of tropane alkaloids including hyoscine. Early settlers near Jamestown, Virginia, reportedly mistook the plant for spinach and narrowly avoided death after feasting on it. The name Jimson weed is a corruption of Jamestown weed.

This plant has been used for many and various medicinal purposes including the treatment of mania, epilepsy and melancholy. It was also sold as a component of herbal cigarettes which were marketed as an asthma relief treatment. There may have actually been some basis in this since the molecules hyoscine and atropine both have relevant biological activity. The asthma drug ipratropium is a structural analogue based on these molecules and is effective when administered by inhalation.

There are also many interesting legends associated with this plant - if you want to find out more come along to the Horticulture Group AGM on 24 September!

Horticulture Industry News

A new source for pectin
For commercial use pectin is usually derived from waste material in citrus processing and cider making. Now pectin extracted from sugar beet pulp is attracting more and more interest because it has unusual emulsifying properties. New work from the Institute of Food Research has shown how sugar beet pectin acts as an efficient emulsifier, using a technique that could be used to unravel in the finest detail how such important food ingredients work. More

New monitoring traps
Vitax has launched a new range of apple maggot and plum maggot moth monitoring traps. They can be used to alert growers so that pesticides can be used to treat the pests. More

Broccoli by injection!
Sulforaphane , a chemical found in broccoli may help in the prevention and treatment of breast cancer. Scientists at the University of Michigan Comprehensive Cancer Centre carried out lab tests on mice and cell cultures with the disease. Those injected with sulforaphane showed a marked drop in the cancer stem cell population (Horticulture Week, 28 May 2010)

Topsoil - the essential guide
In 2009 the Group visited the British Sugar factory at Wissington to see their topsoil unit. With help from students at Writtle College the British sugar team have produce a twelve-page technical booklet which will be a must for those involved in landscaping or amenity management.

Strawberry Finesse
A new everbearing strawberry called 'Finesse' is now on the shelves at Sainsbury's and Tesco. An East Malling Research variety, 'Finesse' produces high yields and the heart-shaped berries are of 'excellent eating quality.' It has no runners and the fruit is well displayed for picking. There are no proprietary rights attached to this variety so it is available to all growers. (South East Farmer, July 2010).

Grants for HortiFair Exhibitors
The Commercial Horticultural Association (CHA) will be leading the UK participation to International HortiFair at Amsterdam RAI in the Netherlands 12-15 October 2010. There are a limited number of UK Trade and Investment TAP grants for eligible companies at this year's event. HortiFair has strengthened ties with the FloraHolland Trade Fair Aaslmeer to create a combined approach under the title 'Holland HortiWeek'. The two organisations will collaborate in organising their trade shows during the same week in November from 2011.

Reading and East Malling get closer
The University of Reading and East Malling Research in Kent have signed an important Memorandum of Understanding (MoU) as part of their ongoing commitment to further learning and knowledge in this area. The MoU was signed by Professor Gordon Marshall, Vice Chancellor of the University of Reading, and Dr Mike Solomon, Chief Executive of East Malling Research, at a ceremony at the University. The newly-forged relationship opens the door for the development of joint research programmes exploiting the strengths of both organisations. This will include joint bids for funding for research and knowledge transfer, a closer involvement of East Malling Research in the University's research on the National Fruit Collection at Brogdale, and the training of the next generation of crop scientists. The MoU will help ensure that research in horticultural crop science is economically sustainable and supported adequately by industry. The agreement also outlines how the two institutions will tackle the issues of academic standards and quality. (see: Co-operation is root to scientific success)

Pink is sweet
A pinkish gooseberry is being renamed as faeberry with the description that it is much sweeter than culinary types. Young bunched carrots at Tesco have been branded 'Bushy Tops'. (Fresh Produce Journal, 16 July).

New Institute, New Director
A leading Scots scientist – currently working in Australia – has been named as the Chief Executive designate to lead Scotland's new, crop, food and land use research organisation. The new institute will be formed from the merger of the Macaulay Land Use Research Institute (MLURI) in Aberdeen and SCRI, Scotland's leading crop research centre based at Invergowrie in Perth and Kinross.

Professor Iain Gordon, who holds both British and Australian nationality currently leads biodiversity research teams across various centres for the Commonwealth Scientific and Industrial Research Organisation in Canberra. More

Growers pay for cheap food….
Food Justice: the report of the Food and Fairness Inquiry, has been published today and finds that farmers, agricultural workers, the environment and consumers are paying a high price for the food we eat. The inquiry committee of 14 came from a broad range of organisations across the food sector and included representation from the NFU.

…Hope may be at hand
An adjudicator to resolve disputes between supermarkets and their suppliers is to be established under plans announced by the government. The Groceries Code Adjudicator (GCA) will sit within the Office of Fair Trading (OFT), but will be independent, the government said. It will investigate complaints from UK and overseas suppliers about the way they are treated by supermarkets. More

Agri-Food Hub
SCI Technical Interest Groups which cover the science and business of food production 'from plough to plate,' are now linked closer than ever before with the launch of the Agri-Food Hub. The aim is to release the huge potential for collaboration between the Groups involved – initially BioResources, Environment, Horticulture and the two Food Groups. Issues around food and the way in which it is produced, processed and sold are never far away, so forging stronger links between these groups and networks makes good sense.

Longhorn beetles found in UK
Following an awareness-raising campaign by Fera, members of the public have reported three confirmed findings of adult Citrus longhorn beetles (Anoplophora chinensis - photo by Paolo Gibellini) in Merseyside, East Sussex and Rutland, and a single finding of the closely related Asian longhorn beetle (Anoplophora glabripennis) in Cumbria. In each case the beetles were captured and there was no evidence to suggest there is an established population of the pest in the UK.

Citrus longhorn beetle is a non-native pest that can be extremely damaging to a wide range of broadleaved trees and shrubs posing a serious threat to horticulture, forestry and native trees in the UK. The beetle is not normally present in the UK, but there have been isolated findings associated with imported trees and shrubs (principally Japanese maple - Acer palmatum). (NFU Horticulture and Potato News 3 August 2010) More

Quotes of the Month

'It's frustrating when you know all the answers but nobody bothers to ask you the questions'.

Anon

eEvents Calendar

Other Events of Interest

International Workshop on Fire Blight
16 - 20 Aug 2010, International Society for Horticultural Science
Warsaw, Poland

International Horticultural Congress
22 - 27 Aug 2010, International Society for Horticultural Science
Lisbon, Portugal

Plantarium
25 - 28 Aug 2010
Boskoop, the Netherlands

International Symposium on the Genus Lilium
30 Aug 2010 - 3 Sep 2010, International Society for Horticultural Science
Pescia, Tuscany, Italy

International Advances in Plant Virology
5 - 7 Sep 2010, Association of Applied Biologists
Arnhem, the Netherlands

Spoga
5 - 7 Sep 2010, Koelnmesse
Cologne, Germany

Four Oaks Trade Show
7 - 8 Sep 2010
Lower Withington, Cheshire, UK

Delivering Food Security with Supply Chain Led Innovations
7 - 9 Sep 2010, Association of Applied Biologists
Egham, Surrey

Saltex
7 - 9 Sep 2010, Institute Of Groundsmanship
Windsor, UK

Abbotsbury Tropical Gardens and Michaud's Chili, Sweet Pepper etc.
8 Sep 2010, Professional Horticulture Group South West
West Bexington, Dorset, UK

Food Security and Safety Symposium
13 - 15 Sep 2010, Society for Experimental Biology
Lancaster University, UK

Green Roofs For A Changing Climate
15 - 16 Sep 2010, London, UK

GLEE
20 - 22 Sep 2010
NEC Birmingham, UK

Peat in Horticulture
11 Oct 2010, International Society for Horticultural Science
Amsterdam, The Netherlands

International Conference on Organic Greenhouse Horticulture
11 -14 Oct 2010, International Society for Horticultural Science
Bleiswijk, The Netherlands

HortiFair
12 -15 Oct 2010
RAI, Amsterdam, the Netherlands

World Emulsions Congress
12 - 14 Oct 2010
Lyon, France

Cactus Pear and Cochineal
17 Oct 2010, International Society for Horticultural Science
Agadir, Morocco

National Fruit Show
20 - 21 Oct 2010, Marden Fruit Show Society
Detling, Kent UK

Workshop on Biological Control of Postharvest Diseases
25 - 28 Oct 2010, International Society for Horticultural Science
Leesburg, Virginia, USA

Crop World
1 - 3 Nov 2010, United Business Media and British Crop Protection Council
ExCel, London UK

Predicting and Controlling the Shelf-Life of Foods
3 - 4 Nov 2010, Food Chain CIC
Leatherhead, Surrey, UK

Know Your Plants - Developing skills for better science, horticulture and communication
3 - 5 Nov 2010, Botanic Gardens Education Network
Royal Botanic Gardens, Edinburgh, UK

Advances in Biological Control
17 Nov 2010, Association of Applied Biologists
Marston, Lincs, UK

Towards 2013. An agriculture fit for purpose
17 - 18 Nov 2010, British Institute of Agricultural Consultants
Wellesbourne, Warwick, UK

Bananas, Genetics and Appropriate Biotechnology
18 Nov 2010, Society of Biology
Nottingham, UK

Tropical Horticulture
22 - 26 Nov 2010, International Society for Horticultural Science
Kingston, Jamaica

Oatridge Conference and Exhibition
25 Nov 2010, Scotgrow
Ecclesmachan, Nr Edinburgh, UK

Innovative ideas in pest and weed control in field vegetables
25 Nov 2010, Association of Applied Biologists
Rothamsted Research, Harpenden, UK

What makes an alien invasive?
7 - 8 Nov 2010, Association of Applied Biologists
Edinburgh, UK

Water and nitrogen use efficiency in plants and crops
15 -16 Dec 2010, Association of Applied Biologists
Grantham, UK

Stress Responses – molecules, organisms, environments
4 - 7 Jan 2011, British Ecological Society, Society for Experimental Biology, Biochemical Society
London, UK

• If you would like to advertise a forthcoming event please contact communications@soci.org.

Horticulture Group Contact Details

For submitting ideas or to volunteer to be part of a committee or a group, please contact:

Acting Chairman - Peter Grimbly
Meetings Secretary - Marion Stainton
Minutes Secretary - Margaret Waddy
Newsletter co-ordinator - Sue Grimbly, E: scihortigroup@btinternet.com
SCI contact - communications@soci.org T: +44(0)20 7598 1500