Spray for blight-pines

Press, 27 April 1984, Page 1

Spray for blight-pines

PA Wellington The spraying of pine trees affected by the needle blight, dothistroma, will be intensified to reduce the disease to its “lowest possible level,” says the director of forest management, Mr Robin Cutler. Stocks of copper spray had been imported each year to control dothistroma, and sufficient was held to double the expected programme, which would begin early this year, he said yesterday. Negotiations to buy additional stocks would begin soon. . “Because there is a possibility that dothistroma-in-fected trees may be a health hazard, spray programmes will be stepped up so that the disease is reduced to the lowest possible level,” Mr Cutler said. The Director of Public Health, Dr Maxwell Collins, said that if the compound was causing cancer it would

take at least 20 years exposure to be damaging. “If it is a carcinogen at all, I believe it is a relatively weak one. I do not think the general public would have a sufficient degree of exposure to consider it a risk ... the most important thing to do immediately is to reduce the exposure of forest workers,” Dr Collins said. Samples of copper fungicide would be called for world-wide, and then tested at the Forest Research Institute at Rotorua, said Mr Cutler. Testing would include the fungicide’s copper content, suspension quality, its corrosive effect on aircraft, and accelerated storage tests. Two advisory committees will investigate the potential cancer hazard of the dothistroma fungus. This was announced at a meeting of representatives of the forest industry and unions with the Government yesterday. The first committee will

be formed next week to investigate the potential health hazard. It will be chaired by the DirectorGeneral of Forests, Mr Andrew Kirkland, and will make its first recommendations in about two weeks. “We will review the information on the compound produced by the fungus, make an assessment from the human health point of view, and make appropriate ' recommendations,” Mr Kirkland said. The forest disease control advisory committee will study action in the forest to reduce infection by dothistromin spray programmes, and methods of control. It will be chaired by the Assistant Director-General of Forests, Mr Alan Familton. Spraying trees with low concentrates of copper seemed sufficient to keep the disease in check, Mr Kirkland said. The potential health threat posed by the fungus

affecting radiata pine was revealed by tests in Sydney. Tests showed that dothistroma might cause cancer in laboratory animals. The hazard to humans is not known. Mr Kirkland said each forest was affected differently. Areas of highest rainfall such as in the central North Island and the West Coast were infected most heavily. Drier areas on the east coast, such as Canterbury, were virtually unaffected. A big forestry company will close areas of its pine forests if surveys reveal serious infestations of dothistroma. H. Baigent and Son, of Nelson, announced the move during a staff meeting yesterday. The Forest Service on the West Coast yesterday moved workers out of areas where pines could be affected. The conservator of forests at Hokitika, Mr P. J. Berg, said that dothistroma had

been present on the West Coast for most of the last 15 years, but he personally did not know of anyone suffering side effects from the disease. Until the situation was clarified, staff had been directed into areas free of the disease. Health Department officials visited forests near Rotorua yesterday to see trees infected by the blight. The president of the Forest Owners’ Association, Mr Brian Wall, said that his association was concerned about the possibility of risk to workers. Staff had been spoken to and were looking at areas they could work in which were least affected. “In terms of continuing to work in the forest, it will be a judgmental decision by the men themselves,” he said. “From the companies’ viewpoint and from the forest owners’ viewpoint, we will do our best to keep things running smoothly.”