29 September 2000

NIABs tips for potato variety stars of future

Seed is arguably the most important input for potato growers. Manage it right and the crop is half way to meeting its target market, but get it wrong and nothing can retrieve the lost ground. In this special we relay expert advice on seed sourcing, report on a new venture in Wales and assess the merits of eye tests. But first, Edward Long asks NIAB to highlight the varieties of the future, sector by sector. Edited by Andrew Swallow

CHIPPERS

CONSUMPTION of traditional chips is static but the market for ready-prepared potato products is expanding. That changes the needs of this sector and brings Markies into the picture, says NIABs Peter Saunders.

Withdrawn from NIAB trials after one year in the mid-1990s it is back as it may suit the growing market for waffles, hash browns and similar products.

In the early chipping segment Premiere still dominates. But that could be challenged by the first early Accord, he says. It produces a good yield of tubers with high dry matter that fry well, and is in its second year with NIAB.

High yields are combined with good resistance to common scab and leaf roll but it is susceptible to virus Y. Also, it could prove to be a dual-purpose type as it has potential as an early scraper, he says.

For maincrop use Dutch-bred Asterix also looks promising, in trials for the first time this year.

"Processors like the red skinned Desiree-like Asterix as it is easy to handle and particularly suitable for extrusion products." However, there are numerous candidates for the chipping sector, he adds.

One Maris Piper-type candidate is Maritiema. It fries well pre and post-storage and could suit the chipping and fresh ware trade. Outgrades are low and it has partial pallida resistance and is good against spraing. But yield lets it down and it is weak for both foliage blight and viruses.

CRISPERS

TURNOVER of varieties in this sector is rapid as new and improved types appear, despite the demand for maize-based snacks eating into the traditional potato-based crisping market.

One that stands out is Courlan from the Fritolay breeding programme in the US.

"Courlan has good sugar stability, reconditions extremely well and has excellent frying qualities so is a possible Saturna replacement. But it is a second early and we do not know how it would cope with extended storage," says Mr Saunders.

Many of the new crisping varieties have only moderate yield potential, but Courlan is better than most, he adds. However, it is not up to the level of Saturna or Hermes.

An interesting characteristic of the variety is that once it does eventually break dormancy its sprouts grow rapidly, two to three times faster than any other variety. Mr Saunders wonders whether this increased vigour could be harnessed to cope with difficult field or seasonal conditions, or whether it could cause problems.

To plug the gap in UK production when Saturna finishes out of store in May, an increasing area of crisping crops are being grown in the south-west. Crispers are replacing early scrapers with varieties such as Lady Rosetta, while Lady Claire is being developed as a possible back-up for Lady Rosetta.

PRE-PACK WARE

SUPERMARKET price wars threaten to shift demand to varieties capable of giving high yield and low unit costs. However, skin-finish quality will have to be maintained though taste may be lost on the way, believes Mr Saunders.

"There are a huge number of new candidates in our trials challenging the current key ones in this sector: Estima, Maris Piper, Marfona, King Edward and Nadine.

"But one which stands out after three years with us is the Caithness-bred Osprey. Intended for the early baking slot it has very good all round performance, produces a good marketable fraction of bold oval parti-coloured tubers with good eating features."

Dual nematode resistance is combined with good resistance to blackleg and leaf roll virus, but it is only moderately good against foliar blight. "It has no major weaknesses and all the attributes needed to satisfy both the market and growers."

Irish-bred maincrop, Shannon, which completed trials in 1999, is also fancied by NIAB. It yields well and produces an attractive sample of tubers with a deep red skin and good skin finish. But the snag is that it is susceptible to most diseases and slugs so is not easy to grow.

Another variety to catch NIABs attention is Caithness-bred second early Celine. It produces moderately high yields with a good sample and pale red tubers, paler than Romano. It has partial pallida resistance and its only weakness in a package of good all round disease resistance is foliar blight.

BAKERS

THIS market grew out of almost nothing in the 1980s and is still expanding, notes Mr Saunders. Dominated by Marfona, Estima and Cara, there are two obvious candidates to compete for a place in this important sector.

"Osprey is one of them and Cosmos, which has had NIAB listing for two years, the other.

"The first early Riviera, from Dutch breeder Agrico, is also a candidate for this slot as it produces an excellent sample of bold tubers. It was National Listed last year."

But beyond that, nothing seems set to break the baker mould. "We have over 30 varieties in the early stage of trialing and so far nothing stands out as having any real commercial potential."

PUNNETS

BIG year-on-year sales increases reflect shoppers willingness to pay value-added prices for this convenience sector. Charlotte, Nicola and the 26-year-old Cambridge-bred variety Maris Peer are the mainstays, while second early type Carlingford, an ex-canner, is also making a comeback as a specialist salad potato, notes Mr Saunders.

Possible newcomers include Serafina, Exquisa and Lady Felicia. Serafina has a long oval yellow-skinned waxy tuber, Exquisa delivers a mass of small long oval tubers with dark yellow skin, and Lady Felicia has a long oval shape and creamy yellow skins.

ORGANICS

VARIETIES good for conventional production systems may not necessarily be suitable for an organic system, warns NIAB.

Over the past two years it has had over 40 tried-and-tested types in organic trials in Warwickshire, Norfolk and Cambridgeshire. The best candidates to emerge for the organic sector include Valor, Cara and Cosmos.

"To be suitable for organic production a variety must be able to cope with low fertility conditions, have sufficient vigour to get off to a flying start to compete with weeds, and have good resistance against disease, particularly tuber blight and slugs," says Mr Saunders.

Remarka is also popular with organic growers but has not shone in the NIAB work. However, many new varieties are in the trials with good field resistance to foliar blight, he says.

These include Appel, Bionte, White Lady, Admira and Naturella. &#42

Could Courlans extra vigour help with difficult conditions, wonders NIABs Peter Saunders.

Record retreat

Records fall has been sudden and dramatic, says NIABs Peter Saunders. From dominating the crisping sector throughout the 1980s and first half of the 1990s the seed certification area has collapsed from 740ha (1829 acres) in 1996, to only 37ha (91 acres) in 2000. That compares with 7300ha (18,038 acres) of Saturna, 6000ha (14826 acres) of Hermes and 4800ha (11,861 acres) of Lady Rosetta.

What will be the varieties to lift potato profits in the future? NIABs BPC-funded trials provide an independent indicator.