6 June 1997

Plan irrigation now to help early beet

EARLY drilled sugar beet is growing rapidly in the sun. As soils approach growth-limiting deficits, growers need to plan irrigation now, says Mike May, senior liaison officer at IACR-Brooms Barn.

"Growers do not normally consider irrigating before mid-June. But half the crops were drilled before Mar 20. Many are already meeting across the rows, three to four weeks ahead of normal. If we do not get any more rain and these drying conditions continue, the need for irrigation will increase."

Mid-June figures in the SBREF Growers Guide show limiting deficits range from 25mm (1in) on coarse sands to twice that on clay loams. Growers can use their own planners. But British Sugars Ipswich and Bury St Edmunds factories also offer deficit information and recommendations.

"The main thing to remember is not to over-water. Apply a maximum of 25mm a pass, and keep soil moisture deficits a few mm below field capacity." That avoids run-off and the need to alter fertiliser requirements. "And provided there is no water-logging, irrigation should not encourage rhizomania if it is present," says Mr May.

Typical pay backs of 2.5t/ha of beet for every 25mm of water can be expected, worth £40/t after deducting the cost of hose reel application, he adds. &#42