18 February 2000

More ways to kill cleavers

As economic pressures bite, the temptation to cut

weed-control corners is growing. This special

focus offers a guide to safe, cost-effective spring

herbicide strategies in cereals, sugar beet and

potatoes. Editor Andrew Blake opens by asking

two distributors to shed light on tackling cleavers

in cereals, where broader product choice could

complicate decision-making

WITH the anti-cleavers spring armoury boosted to six main herbicides this season, winter cereal growers have a better-than-ever chance of getting on top their number one broad-leaved weed, says Dick Neale of Cambs-based distributor Hutchinson.

"In general autumn residual treatments worked extremely well, so the spring clean-up may not seem quite so important this time round." But with just one cleavers plant/sq m cutting yield by 5%, control is well worth pursuing, advises Mr Neale.

Although cleavers do not really compete with crops until first node stage (GS31), the trend is to tackle them before canopies close over to cut the risk of seed return, he explains.

Boxer, Eagle and Platform S are suitable for early application, working better than Starane and CMPP in cooler conditions. "Lotus needs CMPP added to get fully effective cleavers control.

"Platform S does a good stand-alone job on cleavers provided they are all through before its applied because it is contact-acting only. But its tank-mix options are relatively limited." It cannot be mixed with some fungicides or oils used with some graminicides such as Topik (clodinafop), he explains. Boxer and Eagle have similar modes of action, but the latters overall control spectrum is narrower, he notes. "At the full 40g/ha rate Eagle will have a go at black bindweed, but it does not deal with chickweed or groundsel, which is a growing problem. Boxer does."

Eagle scores over Boxer where Lexus (flupyrsulfuron) has already been applied. "A lot of Lexus was used last autumn and there is no label approval to follow it with Boxer for 2000, whereas there is with Eagle."

But Boxer works faster making it more cosmetically acceptable to some growers, he says. "At first sight Eagle often seems to have let you down, being slow to act even a month after application. The key is to leave it – it will work on cleavers in the end."

Once the weather warms in April, Starane and to some extent CMPP come into their own, says Mr Neale.

"The choice depends very much on the temperature. If it is in double figures then 0.6 litres/ha of Starane can do a very good job. If it stays cool I would choose 100ml/ha of Boxer and a whiff of Starane. CMPP is cheaper, but it is beginning to fall behind in the efficiency stakes with cleavers coming back more often than not."

Jostling for a share of the cleavers control spend this spring. Boxer, Eagle, Lotus, and Platform S are all prominent in the picture, along with small amounts of Aurora. CMPP and Starane extend growers options.