On an overcast day at the beginning of this month, the National Institute of Agricultural Botany (NIAB) hosted its annual seed trials showcasing the best new lettuces and endives.
Five seed producers offered developments that they hope will dominate salad production over the next few years. The firms believe that salads produced from their seeds will grow well, show extremely good resistance to disease and be attractive as whole head and cut products.
This year, because of the weather, the range on display was limited. The relative lack of sunshine meant that the trials had to be held late in the season. As a result, some products scheduled for display had already passed their peak. But anyone who drove to the farm and trudged across the fields had the opportunity to see and taste almost 40 varieties.
The open day was held at Flanders Farm in Cambridgeshire, outside Ely. The farm is owned by JB Shropshire & Sons - part of G's Growers group of producers, one of Britain's biggest salad suppliers.
As always, the seed companies were keen to show their big sellers - particularly the Little Gem, Cos (Romaine) and iceberg lettuce, which are by far the most popular salad products in the super- markets. However, there were also plenty of more specialised products on offer.
Tozer has been developing plants with good tipburn resistance. "This is particularly important in the USA, where we sell a lot of seeds," explains product development manager Alec Roberts. The new varieties of Romaine being produced by Tozer all have resistance to tipburn, which is caused by the breakdown and browning of the leaves. They are also bred to have the attractive crinkled or "rugose" leaves.
One iceberg variety in development, number TZ2188, has claimed resistance to the full range of mildew (1-28) as well as resistance to Nasanovia (lettuce aphid). "We're hoping that this will be available for commercial trials fairly soon. It has a good colour, it's not too puffy and grows to around 500g, which is what most supermarkets want," says Roberts.
With the wet conditions, mildew is a serious issue. At the seed trials, Roberts picked out a similar iceberg to TZ2188 that only had resistance to mildew 1-26 and 28 - only lacking resistance to 27. It already had minor signs of mildew.
Roberts is encouraging growers to try out the new products, which are intended as minor improvements over previous offerings. "We would advise them to plant them in a section of their land and see how it goes," he says. "If it works well, we would advise them to change over to the new varieties over a period of two or three years."
Enza Zaden also has a wide range of interesting new products. Many of them are intended for processing rather than sales as wholehead plants. Bellatrix is a compact oak-leaf lettuce, which is marketed as an Eazyleaf - a single cut across the stem will take out the heart and leave a large number of leaves that can be bagged up. "It's very simple to process," says technical representative Andrew Cheer. "The plant has a good taste, without any real bitterness," he adds.
Enza also had a full range of icebergs, intended to meet the overall needs of growers. They all claim 1-28 mildew resistance. Enza is offering Initiation - a larger variety - and Gyration, which is more compact and suitable for more fertile soils. In addition, Enza is offering a slower variety, Buion, which has better field-holding qualities.
For the second year, Enza is showing the Romaine lettuce Totana. "It has a good-quality heart and is attractive in twin packs," says Cheer. It can also be grown as a baby leaf with up to 200 seeds being put into each square metre. It has to be drilled as a pill, he adds. "There's a slightly more complicated production process, but it gives a really good 15cm leaf, which is ideal for bagged salad." Among the seed producers, there is a lot of interest in developing premium products.
Enza also has a range of Little Gem lettuce. Ovired is a red variety, with a good flavour and texture. All have full mildew resistance.
Syngenta offered a wide variety of endives, developed primarily for processing. Friscaro, for example, is an escarole with narrow leaves that can be mechanically harvested. Tests have shown that it has a good shelf life. It is intended as a one-cut product, so that all the leaves can be separated from the stem with a single knife stroke. This makes it easy to package.
Mendes is another escarole that is resistant to tipburn and bolting. It has bright coloured leaves and grows well in cooler conditions, making it suitable for spring and autumn harvesting. Brilliantes is a similar product that has proved extremely popular with growers in Belgium.
Syngenta also showed a number of frisee. Bessie is a medium coarse endive with a good weight. "This is also good against tipburn and has what we describe as a '3D leaf shape' that looks really good in the bag," says seed sales specialist Nigel Kingston.
One of the plants first trialled last year was on display again this year. Funtasia is a batavia-style lettuce with an attractive bellagio curled leaf shape. It is highly resistant to mildew and grows vigorously. Last year, the plant was only known by a number, but is now being marketed widely. None of the Syngenta products has the heavy, bitter flavour associated with traditional endives.
Syngenta was also displaying Mordore, a Little Gem lettuce with red leaves that has a good level of sweetness.
Nickerson Zwann boasts a full range of lettuce varieties - ranging from butterhead to iceberg, Cos and Little Gem.
The firm's lettuce specialist John De Soyza explains that the company is particularly interested in developing varieties that originate in the UK. "We are breeding first-year material that was grown here. One of our big problems is that growers cannot physically harvest the crop all at the same time. So we need crops that have a long-standing and fieldholding ability. If we use crops derived from the UK, we are more likely to find these qualities."
Nickerson is still heavily promoting Antarctica, which has proved itself over the past five years. "We're finding that this is a very popular iceberg lettuce. It has a flat head so it doesn't roll and is easy to handle without getting damaged. And it won't develop into a cone shape when the sunlight is poor. It also has high tipburn tolerance and thick leaves that don't dehydrate rapidly." These qualities make it useful as a pre-pack, whole-head lettuce.
Antarctica is being promoted with a more recently developed iceberg - Shetlandia. This is slightly quicker growing, which means that growers may want to plant Shetlandia and Antarctica varieties in tandem. Shetlandia has good taste and well controlled ribs.
The firm is currently developing other icebergs, but they all have yet to prove themselves. Nickerson is also working on new varieties of Cos and Little Gem - many of which are being bred from first-year material derived from Britain.
Seminis was only showing iceberg at the seed trials. Product sales specialist Jeremy Booth says that although a number of new lettuces were in development, the firm had tended to stick to tried and tested varieties. "We've been growing Stallion. It's an old variety, which is very reliable and performs well. It's ideal for supermarkets - it's got a nice flat head so you can put a label on it," he adds.
Affic is another iceberg for whole-head production. It was also bred in Holland. It grows slower than Stallion and so has a field-holding advantage.
Bombastic is a new variety that is currently being evaluated but is not yet being fully marketed in the UK. It has a slightly larger head - fitting around nine to a box. It also takes three days longer to grow than Stallion, which means that the two can be grown in tandem. According to Seminis, it has full resistance to mildew.
Another new variety is Tassic, which until last year was simply known by a reference number. This has a large head and base, which means that it can be used for whole-head production or can be processed. It is mid-maturing so is useful for spring and autumn production.