Rooting for early spring trigger to OSR growth

This year’s OSR crops have, for the most part, established well in favourable autumn growing conditions, reported the Syngenta iOSR grower group.

Although vigorous leaf growth is likely to drop back in any hard frosts over the winter, good root structures have been put down that can be expected to power early spring growth.

That means growers could be looking at early spring fertiliser requirements, so as not to hold back the initial growth, advocated Syngenta Technical Manager, James Southgate.

“The strong autumn foliar growth will have used up a lot of the residual N, and although the GAI may go backwards in February, any nutrients in shed leaves won’t have been recycled to support early growth.”

However, whilst crops need some early nutrition, growers should be mindful of applying too much N in initial applications.

“The aim is to set the crop up for an optimum Green Area Index (GAI) of 3.5 as they come into flower,” advised James.

He highlighted there will be a tendency for this early growth to surge through growth stages.

"That can be effectively managed with spring PGR applications - to hold back stem extension and develop side branches for a strong and efficient crop canopy.”