Deal with slow emerging yield robbers in sugar beet

UK - June 03, 2005

Growers may be compromising control by waiting too long before spraying volunteer potatoes or thistles in sugar beet warns Dow AgroSciences.

"Volunteer potatoes are emerging slowly this season. We've had reports of growers waiting until most of the plants are up, but this could mean the first flush of volunteers will be too big to be controlled," says Dow's Colin Bowers.

"The potatoes have to be targeted first when they are between five and ten cm tall. Further applications should be made 7 to 14 days later when the shoots are between 10 and 20 cm. In the long-term sugar beet is one of the best crops in the rotation to control volunteer potatoes so it's worth doing properly."

For the control of volunteer potatoes, Dow recommends a total of 1.0 l/ha of Dow Shield by the end of June, either using split applications of 0.5 l/ha Dow Shield, or spreading it over three applications of 0.35 l/ha.

Growers phoning Dow's technical hotline are also reporting creeping thistles still emerging in sugar beet crops. A thistle patch that has just four stems per square metre will cut beet yield by the equivalent of 4 t/ha on that patch. At a mean ABC current quota value of £28.80/t, this equates to a loss of £115.20/ha.

"Dow Shield can be applied twice for good control of established populations of creeping thistle. The first application at 0.5 l/ha should be made once the thistles are at rosette stage, with a follow-up application of 1.0 l/ha three to four weeks later," advises Mr Bowers.