OILSEED RAPE growers should be prepared to steady down forward crops this spring to prevent lodging, BASF has advised.

With many winter-sown crops now approaching the stem extension stage, growth regulation may be required, particularly on crops sown early at high seed rates, said the firm‘s Diane Heath.

Using the Green Area Index (GAI) can help growers assess whether growth regulation or adjustment to nitrogen rate is required, she said.

“GAI is the ratio of green tissue area to the area of ground on which the crop is growing. It can be measured by eye, or by measuring fresh crop weight from one metre2 and multiplying the weight in kg by 0.8.

“Canopies likely to benefit from plant growth regulation are those with a GAI of greater than 1 in March and greater than 2 in April,” she explained.

Guidance on calculating GAI is available in the Home Grown Cereals Authority‘s Topic Sheet No.82, she said.

Ms Heath recommends using the broad spectrum fungicide Caramba (metconazole) to improve stem strength, increase branching and produce more flowers.

“In the spring Caramba should be applied at mid-stem extension for growth regulation when growth is active and weather is warm.”