19 November 1999

Go back to storage basics

By Amanda Dunn

IF farmers are to meet the requirements of increasingly demanding consumers, they must go back to basics and stop relying on a quick-fix pesticide approach to grain storage.

So says Ken Wildey, head of storage research at CSL York. "Although the UK grain industry is without doubt of the highest quality, we need to look to the future, determine the challenges and address how we are going to meet them."

Current concerns include pesticide residues, mites both as a food contaminant and an emerging allergenic issue, and mycotoxin levels.

"There is increasing pressure to remove some of the grain protectant products. 13t of organophosphate active ingredient is applied to the inside structures of UK grain stores each year. The review of OPs is current. It may be that fewer products will be available to us in the future."

Coupled with that is a longer-term rise in consumer demand for nil pesticide residue.

Farmers need to switch to fast cooling and drying together with regular monitoring to avoid pest problems, says Dr Wildey. "Stored grain should be kept under 10C, and at moisture contents of 14.5% for cereals and 7.5% for oilseed rape.

"Target moistures should be reached within ten days and grain cooled to 15C in fourteen days, 5C by December," explains Dr Wildey. "Costs of cooling may well be cheaper than farmers envisage. Taking grain in at 18C and cooling to 5C by December will cost in the order of just 10p/t. It is a myth that cooling costs a lot of money."

There is also good evidence that cooling and drying grain using damp air will not significantly transfer moisture into dry grain, Dr Wildey says. "As long as there is a difference of 6C between ambient air and grain, the air will still cool grain without dampening." Rather than wait until conditions are ideal, farmers could continue cooling in damp conditions.

Cereals and oilseed rape must be handled slightly differently, he adds. Using the same system for both may lead to problems. "Oilseed rape has a greater resistance to aeration, so should be stored at half the depth, or the power of the fans doubled.

"Grain monitoring is a requirement of ACCS, but it can also save money. Why treat a store if there isnt a problem?" he adds.

Even if a store is treated, it does not mean monitoring can be avoided. "Beetles are so cryptic, they will hide and avoid contact with pesticides. Chemical application will kill hundreds of thousands, but it wont kill all of them. You still have to monitor and ensure that grain in store will not be suitable for pest development," says Dr Wildey.

STORE ADVICE

&#8226 Dry cereals to 14.5% and osr to 7.5% in 10 days.

&#8226 Cool to 15C within 14 days and to 5C by December.

&#8226 Continue cooling even in damp weather.

STORAGE ISSUES

&#8226 Grain stores designated as food premises.

&#8226 ACCS.

&#8226 Mites as food contaminants.

&#8226 Mites and allergies.

&#8226 Pesticide residues.

&#8226 Organic products.

&#8226 Mycotoxins.