Rise in cranes bill confirmed
Rise in cranes bill confirmed
COMMENTS that cranes bill could be creeping up the weed league (Arable, Apr 12) are supported by a recent national survey of weeds and an independent agronomist.
Data from the Suffolk-based National Farm Research Units national crop weed survey shows cranes bill was found in 29% of winter wheat and 15% of winter barley in 2001. That compares with just 21% and 19% respectively in 1993.
Scotland had the highest incidence of the weed last year, with 46% of winter wheat affected, closely followed by the east midlands at 41%, the south-east at 36% and eastern England at 34%.
"It is becoming significant," says independent agronomist Richard Palmer of Farm Vision. "It forms quite a carpet, particularly on the headlands."
About 50% of fields he walks, ranging from the Cotswolds to central Lincs and across into Norfolk, contain the weed. Highest incidence is on heavyland, he says.
However, that may be more to do with rotation than soil type. "Theres more of it where oilseed rape is grown because theres no control in that crop."
In cereals control revolves around sulfonylureas such as Ally (metsulfuron-methyl). Lexus (flupyrsulfuron-methyl) applications, primarily targeted at blackgrass, have had a knock-on benefit, he adds.
While cranes bill may be increasing in incidence, it still lags way behind the three most widespread broad-leaved weeds in the survey – cleavers, mayweeds and chickweed – which affect 95%, 81% and 74% of winter wheat crops respectively. *
Cranes bill crescendo?
1993 1997 2001
W wheat 21 25 29
W barley 19 20 15
S barley 9 8 7
% incidence by crop. Source: National Farm Research Unit.