Brassica quality is the goal

Vegetable growers know that they must grow the highest quality produce for the supermarkets and that means making sure that disfiguring and yield affecting diseases are kept at bay. A Kent-based specialist agronomist, Martin Christopher sees Signum as playing an important role in this goal.

Advising brassica growers in Kent for UAP, Martin Christopher points out that ring spot, caused by the fungus Mycosphaerella brassicola, is a particularly disfiguring disease in many over-wintered crops such as sprouts and cabbages. "Downy mildew can escalate when the weather is appropriate, as it has been already this year. White blister, (Albugo candida) is also becoming much more widespread, particularly in the South East and can spoil both yield and quality of summer cauliflowers and summer sprouting broccoli. These last two diseases flourish under the same conditions as potato blight and so I would expect both to become significant problems this season."

Martin says that the fungicide Signum has a role to play in reducing the impact of these diseases in brassica crops for which it is recommended. "In particular it is a much more benign material when it comes to crop safety and will naturally fall into the early slot when the crop can often be heat stressed. You want to avoid using aggressive fungicides which could dewax the crop. Later in the season when some curative activity is needed or intervals are being stretched, it can be tank-mixed or alternated with a triazole or metalaxyl containing product," advises Martin.

"Signum is recommended on a wide range of brassica crops, either on the label or as SOLAs*, and it gives excellent protection against virtually all common diseases of brassicas, resulting in clean and spotless produce."

Signum has a label recommendation in Brussels sprouts, cabbages and cauliflowers. There are also a number of SOLAs* from which growers can benefit, including protected and outdoor leafy brassica crops grown for baby leaf production, outdoor and protected Chinese cabbage, outdoor collards including spring greens and outdoor kale.

"Signum gives excellent control of all the important brassica diseases - dark leaf spot and white blister plus useful control of ringspot. Both actives in the product, boscalid and pyraclostrobin, also have activity on powdery mildew. This broad-spectrum control makes Signum a key brassica fungicide and one well accepted by growers and retailers alike," says Matthew Blaken, BASF Field Vegetable Manager.

"But Signum is not just an excellent broad-spectrum fungicide. It also shows extra plant health effects that are particularly significant in vegetable crops where quality, visual impact, yield and shelf life characteristics are so important," he says.

BASF advise that Signum should be applied early. "The first Signum spray should be applied to brassicas as a protectant before the first signs of disease are seen at a dose rate of 1 kg/ha in water volumes of 200 litres. Further sprays can be made at 3 to 4 week intervals, alternating with products from a different resistance group."

Martin Christopher of UAP concludes that growers are very receptive to using an anti-resistant strategy but are keener on having a range of products that work robustly to solve the problem. "There is such pressure from the supermarkets on vegetable growers, not just to grow high quality produce but to do so whilst delivering evidence of pesticide reduction in audits," says Martin.