Establishing the variety plots for the seventh annual British Carrot Growers' Association demonstration proved challenging for grower Guy Poskitt this year. The demonstration site at Wood Farm, Whitley, near Doncaster, was drilled with 42 varieties on 12 May but was hit by a severe gale on 22 June that caused soil blow across much of the site. However, subsequent rain and sun encouraged strong growth and produced an impressive display when the site opened to growers on 9 October.
Seed was supplied from Elsoms Seeds, Nickerson Zwaan, Clause UK, Seminis Vegetable Seeds, Nunhems Seeds and Rijk Zwaan. Among the varieties a host of new and improved types had been developed in response to production trends, market conditions and cost concerns to meet UK standards.
With the threat of reduced pesticide options, disease-resistant strains were in strong evidence across the board, with some good developments in resistance to Sclerotinia, cavity spot and scab. Yield and taste remain important in the development of new varieties, with attention paid to flavour and colour, crop uniformity and strong roots to prevent breakages pre- and post-harvest. Earliness and flexibility of sowing to extend seasons was also high on breeders' agendas.
British Carrot Growers' Association chairman Martin Evans says growers will be looking for varieties that sell well while responding to challenges within the industry. He says: "We're looking for varieties that will deliver more customer benefits while remaining responsive to future and ongoing threats such as climate change and dwindling pesticide options for our crops.
"Diets have changed and products are being sold differently - I'm now supplying Marks & Spencer with ready-to-cook carrots in thyme and honey, which would have been unheard of a few years ago. We need to run the trials alongside these changes to access varieties that fit these shifts in the market. And we're always looking out for something that surpasses the current market leader."
Most carrot growers and seed companies acknowledge the importance of Nairobi F1, from Elsoms Seeds, as the UK market leader for carrot production.
Elsoms says Nairobi F1 is the most versatile for market; it has the potential to be used for the earliest polythene-covered sowings, through to late sowings for over-wintered straw-covered crops. At lower seed populations, Nairobi can be grown for processing, and produces high yields of bulky, strong roots, well-suited to the pre-pack market - approximately 112 days from sowing to maturity. The variety has become a benchmark that all seed suppliers aim to surpass.
Size and strength
Elsoms seed sales specialist Chris Bettinson says: "Nairobi's strengths lie in its good taste, high yield and its ideal size for the pre-pack market. We and our competitors are looking to develop varieties that out-yield Nairobi.
"We're looking to build a good portfolio to spread across the early, second and late crop production cycle. Notable new favourites for the early slot include Norwich, Norwalk and Nominator. Nantucket is the current number-one early variety, but through trialling these new varieties we hope to bulk up for commercial production within four to five years to offer some strong rivals.
"Norwich and Nigel are good second-early options. Norwich has strong top growth meaning it can be lifted earlier and is good for top lifting - the preferred harvest method for most growers."
Bettinson says varieties that grow too long in sandy soils are proving good late-crop options eslewhere. He says: "Our new Nervi F1, Nepal and Nero are great options for growers working on peaty, black soils as opposed to traditional sandy-soil production. They take longer to grow but this just makes them a good option for over-winter storage."
Growing in dark soils
One of two new varieties from Seminis Vegetable Seeds also caters for growers producing on dark soils. According to seed specialist Duncan Griffiths, the as-yet-unnamed 2269 attains a good length in peat soils where other strains may struggle. He says: "It's a slightly more slender variety but keeps its length in dark soils where others may stay short. It's a slower-developing type, bulking up later in the year, making it a good late or over-wintering variety. It also suits organic soils."
The company's second offering, Carrazzo, is a main-season/late variety for the fresh-produce market. Both varieties are comparable in yield to the industry standard. But Griffiths says Carrazzo surpasses most varieties in terms of disease resistance. He adds: "In the past two years of Processors & Growers Research Organisation (PGRO) testing it has come out very well in the carrot spot-testing.
"Having been inocculated by PGRO after harvest, it has come in among the top three varieties for storage resistance against cavity spot - significantly better than the majority of varieties available on the market at the moment."
Nickerson Zwaan vegetable seed specialist John DeSouza says the company now has the next generation of carrots to rival the market leader. The main-crop Vac series - predominantly Nantes hybrids - comes out of intensive UK screening trials to offer strong crops with high disease resistance. DeSouza says: "The Vac series offers seven varieties all with strong roots, good for mechanical harvest and showing strong disease resistance, particularly to Sclerotinia, which has been a particular problem this year. Vac 50 F1, for example, is an improved Maestro type offering improved strength and is distinguished by its sweet flavour. It is in development and will be commercially available in two years. Yield possibilities give the series an advantage over the market leader. "
He believes the firm also has a unique option for over-winter storage with the development of Eskimo. He adds: "Eskimo is one of the few varieties bred for frost tolerance, extending the field harvest period to December. Frost tolerance means there is no need for straw or polythene, saving growers cost and effort. It's a late main crop, with high marketable yield for standard fresh pre-packed and loose options."
John Ward, development manager at Clause Vegetable Seeds UK, says the firm's aim with any variety is to get yield to an acceptable 120-130 tonnes/ha. As such, it has developed the Nantes variety Match F1, which he says will give Nairobi a run for its money. He says: "Nantes varieties give growers flexibility to sow from December to June and achieve high yields throughout the year. Match F1 offers a high yield to rival the market leader but also has the advantage of holding its tops well for a longer period, allowing for late top-lifting, and is good in storage until May.
"Its improved foliage allows for better air movement around the base - better for spray application for outbreaks of Sclerotinia."
He also notes the development of the uniform Gemma F1 for the processing market. Unlike some varieties it holds no white core, which Ward says translates to losses in production in the factories. Small quantities of seed are available.
Nunhems Seeds offers Elegance as its main variety, and as a rival to Nairobi in the UK. Nunhems carrot sales specialist Roland Koets says it is a slightly quicker crop with smooth skin and stronger foliage compared with Nairobi.
He says growers also have a good new option with Romance F1: "Our Romance F1 offers strong resistance to Sclerotinia and produces strong tops and good flavour - we're already seeing success. Most carrots grow in length and then bulk out; Romance bulks as it lengthens and results in a good flexible root for harvest, reducing breakages."
The trials are about new varieties and staying up to date with changes to older varieties. Rijk Zwaan has offered Caradec for the past few years for use in the pre-pack market, but is seeing better opportunities for the variety in the processing market. Open field manager Keith Stephen says: "We're finding that Caradec really ticks the boxes for the processed market. It's a good-tasting variety, with very dark internal colour and high carotene content, making it especially good for processing into batons. We've re-trialled it as such this year and it's proving very good for that market."
Stephen says that all breeders are chasing Nairobi sales but that the firm's new Stanford is a strong rival: "Stanford fits in alongside Nairobi but with several advantages - it shows strong resistance to Alternaria and produces a short top, making it more suited to top-lifting and storage. Germination and uniformity are good, we've seen reduced problems with cavity spot. Stanford is turning out to be a good option for the pre-pack market."