Glyphosate

Nobody in professional horticulture can be unaware of the issue of Glyphosate. The EU is reviewing its licence and it is going right to the wire. rather like the Brexit debate, the rhetoric is being cranked up and both sides are quoting  lots of  data to further their cause. There is also a lot of nonsense and quite frankly, dodgy science being quoted and this is not serving any purpose.

The debate should be settled on scientific data, some pressure groups are using it as a means of giving Monsanto a good kicking just where it hurts- in the profits. Monsanto are certainly no choir boys when it comes to corporate ethics but if they need holding to account, this is not the best way to do it.

What is not being given enough consideration is the fact that weeds are becoming increasingly resistant to Glyphosate. Willowherb, perennial nettle and I am told, dandelion  can sometimes need a second application of the chemical for total control. I can remember reading an article in Horticulture Week about 20 years ago in which the author spelled out the dangers of over-reliance on Glyphosate in that it would lead  to the development of resistant strains of weed. This has certainly happened. There has also been some concern about plant damage caused by Glyphosate, a former curator of the RHS garden at Wisley  told me that he had noticed damage to Sorbus and Viburnum following Glyphosate application even though no foliage had been touched. I have noticed healthy specimens of Viburnum opulus killed outright following Glyphosate use.

Nature cannot be influenced by lobbyists nor pressure groups, like many pesticides Glyphosate use may be limited by resistance as much as legislation. I regretted the withdrawal of Ammonium sulphamate due to high registration costs, this was a useful chemical and I am not aware of any environmental or safety issues surrounding its use as a herbicide. I stand to be corrected.

In amenity horticulture, the Glyphosate issue has stimulated the development of various alternative control measures such as hot water, hot foam and acetic acid. Only time will tell if these alternatives can do the job of replacing Glyphosate  for specialist application such as Japanese Knotweed control but they are welcome developments. For too long, we have had all our eggs in one basket and that is not good.