16 March 2001

Knives out for organic crops

ORGANIC crops taste no better than conventionally grown produce and in the case of bread can be inferior, delegates at an International Fertiliser Society symposium in Lisbon heard last week.

Jorma Kumpulainen, of the Agrifood Research Centre in Finland, said consumer taste tests showed quality fluctuated far more in bread containing organic wheat flour than those made with conventional flour.

The culprit is the consistently low protein content of organic wheat flour and lower levels of nitrogen and nitrate, leading to lower loaf volume and lower quality.

Further tests show no consistent taste benefit for organic milk, potatoes, green beans, broccoli or spinach over conventionally-produced alternatives.

"The widespread belief among consumers that organically-produced foods are healthier than those produced by conventional methods is not based on sound scientific knowledge," said Dr Kumpulainen.

He also highlighted a slight trend to higher phosphate levels in organic crops, prompting concerns that slowly-dissolving phosphates used in organic farming could contain high levels of cadmium.

Background levels of DDT and banned organochlorine pesticides were the same in organic and conventional crops and pesticide residue levels were mostly below the detection limit in both, he said.

Most evidence on the vitamin content of food grown under the two systems is evenly split. But storage losses are lower in organic potatoes which have slightly higher levels of vitamin C. Organically-grown leafy vegetables are also likely to have higher levels.

&#8226 Bernard Tinker, of Oxford Universitys plant sciences department, said a large switch to organic farming and its 30% lower yields would make it impossible to fulfil expected world cereal demand of 3046m tonnes by 2025. Prof Tinker questioned the sustainability of stockless, organic arable farming as well as its lack of control of polluting nitrates released by ploughing. &#42