Black-grass is still considered to be very difficult to control by over two-thirds of farmers according to a recent survey. Interviewing 97 top farmers, growing a minimum of 70 hectares of wheat and 30 hectares of winter barley each across the key arable growing areas of the UK, the survey also indicates over half are dissatisfied with the level of weed control they are achieving.

Asked how easy or difficult black-grass was to control, on a scale of 1 to 10 with 1 meaning it is easy and 10 very difficult, 62% of farmers scored between 7 to 10, indicating that this weed is seen a big challenge to control. The survey also indicated that over half of the farmers (54%) were dissatisfied with levels of black-grass control that was achieved. The main reasons for their dissatisfaction were resistance to existing herbicides (45%), poor efficacy of herbicides (25%), lack of effective products (25%) and high cost of investing in herbicides (25%).

Many farmers also said that the problem of black-grass was getting worse or at least remained consistent, particularly in the South and the Midlands - very few thought the problem was getting any better. The main reasons for the worsening black-grass problems were resistance to Atlantis, the trend to minimum tillage, loss of lower resistance risk herbicides (such as IPU and trifluralin), wet weather last season and increasing target site resistance, which is absolute resistance.

The main ways that have been adopted to improve black-grass control were the use of pre-emergence herbicides (cited by 44% of respondents), changing crop rotation (42%), more focus on ploughing and other cultivations (38%), later drilling (28%), using different herbicides (27%) and use of stale seedbeds (15%). Practises that were not widely adopted were taking more advice (11%), applying more treatments (8%) and using more expensive herbicides (7%). There was a very strong level of appreciation by farmers of the importance of pre-emergence herbicides, with 83% supporting this view.

Asked, apart from price, which particular attributes of an herbicide were important, 46% of farmers choose the level of control of both resistant and non resistant black-grass with 17% choosing control of other grass-weeds and broad-leaved weeds, 14% were looking for a boost effect and 12% a long-lasting effect from their herbicide.

Most farmers in the survey (65%) used their distributor supplier as their main source of crop protection advice and information on cereals, with 28% using an independent advisor. A further 4% used an advisor from a buying group and 2% used their own knowledge on crop protection.

Dr. Dominic Lamb, UK and Ireland Business Manager for Gowan points out that Avadex (tri-allate) has a different mode of action to most other residual herbicides and has no problems of weed resistance, even though it has been used in the UK and Europe for 50 years. "This is particularly pertinent as resistance is cited as the key reason for black-grass escalation."

Dr Lamb reminds growers that Avadex Granules is available to use this autumn and will be marketed alongside other tri-allate formulations under development in the future. "This farmer survey validates the importance of a product such as Avadex within a weed control programme this season, not only for the effective control of black-grass but also in the fight against herbicide resistance which has such high relevance in the minds of growers. We are certainly seeing an increasing number of growers interested in integrating Avadex into their weed control programme this autumn."