8 October 1999

Green straw challenge

COPING with lots of greener than usual straw from cereals treated with strobilurin fungicides is a real issue for growers adopting reduced tillage systems.

This year strob-greening made straw chopping very difficult for manager Peter White at the farm of K Mawer & Co, Leyfields, Kneesall, Newark, Notts. To speed harvest he raised cutting height, but the resulting long stubble proved a headache for the Simba disc and double disc press train pulled by a Class Challenger at 9-11 km/h (5.6-6.8 mph).

Difficulty incorporating straw into easy working soil is very evident in one rape field. "It doesnt look very pretty, but we wanted to drill before the rain and the Simba Freeflow drill travelled without trouble so we went in with 4.75 kg/ha of Madrigal," says Mr White.

He believes combine makers can help. "Combine manufacturers must improve both the straw chopping and chaff spreading if reduced tillage is to succeed," says Mr White.

But farmers can help themselves too, by reducing seed rates for early drillings, keeping the crop standing and, when necessary, using a pre-harvest desiccant to counteract strob-greening, he adds.

"Straw management at harvest is critical," admits Colin Stride, ECOtillage technical services manager for Monsanto. "The combine should cut lowish, the straw should be chopped short and both straw and chaff evenly spread," he advises. &#42