Fertiliser manufacturer GrowHow has warned hundreds of producers across the UK that some of its bags have a fault, making them prone to splitting.

The biodegradable bags have a weakened side wall on the outer skin caused by a UV-inhibitor in the blue dye.

GrowHow’s marketing manager Ken Bowler stressed that it was a specific batch and that the company had written to all of the growers who could be affected.

Mr Bowler was unable to put an exact figure on the number of bags involved but said hundreds of growers had been contacted.

“Anyone who gets a letter should inspect the side wall for any signs of weakening,” said Mr Bowler.

Where bags are exposed to sunlight he suggested they could be covered but to leave them in place rather than make any unnecessary extra movements.

“The best advice is for the producers who get a letter to contact their local GrowHow representative,” Mr Bowler said.