Report Of Sweet Briar Control

Press, Volume CII, Issue 30152, 8 June 1963, Page 6

Report Of Sweet Briar Control

“T WAS interested to see what appeared to be completely successful results with a modified treatment using 2,4, 5-T,” said Mr L. W. McCaskill director of the Tussock Grasslands and Mountain Lands Institute, after his return from Australia last week. He was discussing control of sweet briar.

One of the large chemical firms had produced—from 4000 tried—a new emulsifying agent which enabled a water-in-oil mixture to be made as opposed to the usual oil-in-water formulation The material was known as “invert” 2.4, 5-T. The emulsion produced was densely white, so that it could readily be seen where it landed. There was a great reduction in volatility and drift, and as the chemical was contained within the oil film on the outside of the water it was much more efficiently absorbed by the plant. Canes were sprayed up to a height of about 18in, and the application was continued until a white mist showed on the bark. Winter spraying in July and August had proved most effective. Mr McCaskill satd that the

trial plots he saw had been treated only once, and they showed no regrowth at all The results, both on these plots and on trials made by farmers, had been so encouraging that the firm concerned had modified the pumps used to give the extra pressure needed tor handling the different form of emulsion. “1 am inquiring whether this ‘invert’ 2. 4 5-T has been used in New Zealand,” said Mr McCaskill, “as I would like to compare the results with what I saw in Australia.”

(In August last year Mr B. G. Long, a noxious weeds officer for the Berrima County Council in New South Wales, was quoted on this page as reporting success with invert 2.4, 5-T against briar in Australia.) Mr McCaskill said that he had been interested to see areas of the tablelands in New South Wales where briar was, in some cases, as big a problem as in many parts of New Zealand. On some areas where the carrying capacity was so low that any expenditure on briar control was considered uneconomic, the weed was spreading rapidly.