27 February 1999

LAST YEARS spring rain meant many potato growers didnt get the crop in the ground until very late. With temperatures now warming up slightly, should growers be ready to go in as soon as they can in case the weather catches them out again?

You could argue every single year that soil conditions in February might be the same as in April or May, but frosts can decimate an early-drilled crop and the risk is higher in April and May.

Pentland Javelin, Marfona and Estima are three important varieties that will have a short-lived canopy if planted in cold weather and poor soil conditions. But Cara and Maris Piper could be planted in the last two weeks of February or in early March without penalty.

Many soils are currently still draining, and heavy soils in particular need time to dry out. These need to be progressively cultivated to dry the soil out at depth.

Crops following sugar beet are likely to experience problems because of the lack of soil weathering this winter. Where theres compaction from the previous crop, excessive cultivation will be needed to produce a clod-free tilth. The problem here is that too much working can reduce good soil structure to finer, structureless particles, so that beds can slump quite badly after rain. Dont use excessive energy to create the seedbed; wait until conditions are suitable.

Clever growers may make one or two fewer primary cultivations and leave a small proportion of clods in the seedbed after declodding or destoning. These will be broken down by wetting – rain or irrigation – and drying, during the season. For control of common scab, seedbeds should be fine but not structureless. Clods left at the end of the season could be taken out with Dahlman rollers but this risks scuffing or pinching the tubers.

Dr Mark Stalham,

Cambridge University Farm, Cambridge.

Ramularia riposte

I was delighted more attention has been drawn to ramularia on spring barley (Ramularia Rampage, Crops, w/e 30 January 1999).

It now seems that this disease has had a significant impact on certain spring barley varieties across northern Europe in the last two years. However, I was most alarmed by the photograph you showed in the article for it is clearly not ramularia. What is shown is probably septoria on barley (possibly S avenae triticea) which is not uncommon late in the season during wet years (such as 1998). I am therefore concerned that the claimed gross margin response to strobilurins may, through mis-identification, be related to septoria control and not ramularia.

Misidentification of ramularia is quite possible for there are a number of pathogens and non-pathogenic disorders that produce symptoms with which it can be identified.

Dr Stuart Wale, Head of Crops Services, SAC, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen.

Editors note: Case not proven yet, it seems. DR Keith Dawson of CSC Cropcare remains adamant that ramularia is present in the complex of symptoms in our published photograph.

Hybrid hype?

With Crops w/e 13 February is a card, entitled Crops Profit Pointer, presenting hybrid spring rape varieties. The claims for profit potential are based on UK data but this could mislead Scottish readers.

The SAC spring rape list based on four years of trials in Scotland shows the conventional variety Maskot is higher yielding than all the hybrid types. As a conventional variety, Maskot seed cost per hectare is much less and so using SAC data it produces up to £27/ha (£10/acre) greater gross margin. As an early maturing variety, Maskot is proven both on farm and in trials in Scotland.

I am sure you would agree growers should be advised to choose the varieties proven to be successful in their own regional conditions.

James Wallace, Daltons of Peterborough, Eye, Cambs.

Cake for all

Marie Skinner should have read the letter from John Cobbald (Crops, w/e 13 February).

She might then have realised that agricultural policy cannot be tailored to suit her needs. Probably the only thing worse than filling in the MAFF questionnaire is not filling it in. She should be aware by now that this Government considers that lack of opposition is a mandate to press forward with any policy it wishes.

Marie Skinner has made it clear in the past that she sees agriculture as one cake, and by advocating ACCS seeks to claim as big a slice as possible at the expense of smaller farmers. Hardly surprising then that she fears the smaller farmers will want to grab the slice back by supporting capping. In my case she need not have worried; I gave answers that cannot be used against us, and I suggest others do the same. It is time for us to stop seeing each other as competitors and work together against the real opposition.

Martin Harris,

Home Farm, Newborough, Peterborough, Cambs.

FEEL the quality! Four malting scholars from China are comparing British-grown malting barley with that from France, Denmark, Australia and Canada at Heriot Watt University.

Find out if British is best when the results are announced at HGCAs British Cereals Exports malting barley seminar supported by Crops – the Best Barley in the World – at Botley Park Hotel, Botley near Southampton, on 17 March.

The programme will include an update on HGCA research on malting barley, as well as a world market outlook and views from European, Brazilian and Chinese buyers. Plant breeders, traders and maltsters will also look at the implications of the world market for the industry.

Malting barley prices may not be booming, but the outlook is promising with world beer consumption set to rise by 4% a year. Experts predict demand for malting barley could rise by 25% – 3.5m tonnes – over the next decade.

To attend, contact Dorit Cohen at the BCE on 0171-520 3925.