Consider quota bracket when making beet fungicide plans
MOST sugar beet crops are expected to hit target yields and growers should consider which quota bracket extra tonnage will fall into when making fungicide decisions, says IACR Brooms Barns Mike May.
"80% of the crop is excellent, and the rest is only a little gappy. Most growers are on target for quota, so long as they have not cut back their acreage too drastically," he says.
"If you are growing a large area and are going to be way over quota one has to question whether you need to put the input on."
But with yield responses of 10-15% possible even extra C beet at £4/t can be worthwhile, he adds. (see table).
Powdery mildew is the main target, and should be sprayed at first sign of the disease. For most growers that will be in August, spreading west and north from the Ipswich area. Nationally, about 50% of the crop is forecast to be affected.
Where crops are to be lifted early, sulphur (as in Thiovit) at 10kg/ha (9lb/acre) is recommended, but for later liftings a triazole plus sulphur at 5kg/ha (4lb/acre) mix should give the best response.
"In some years the triazoles seem to increase green leaf area and increase yield more than disease control alone. Even at a C price of £4/t that can stack up."
Using a triazole will also give rust control, he adds. *
How clean does beet need to be if extra yield is destined for C-quota? In most cases a triazole spray will still pay, says IACR Brooms Barn.
Sugar beet fungicide
Product Cost Margin Margin £/ha @ A/B @ C price price
Thiovit 6 92 10
Tilt 11.5 64 2
Alto 13.5 118 8
Alto + Thiovit 16.5 119 5
Punch C 16 232 23
Punch + Thiovit 19 309 33
IACR Brooms Barn yield data, British Sugar prices. A/B price based on 70% A quota @ £33/t, 30% B quota @ £8/t. C price £4/t.