No risk from pine tree abnormality

Press, 27 May 1981, Page 3

No risk from pine tree abnormality

PA Rotorua Forest Research Institute scientists are satisfied there is no risk that the abnormality discovered in pine forests in Northland, will spread. The scientist heading the team of forestry pathologists investigating the problem. Dr G. B. Sweet, of Rotorua, said there were no signs that the abnormality was spreading at the moment. The affected ' areas w'ould be burnt as sobn as possible. If a disease had been responsible for the abnormality, the burn-off would prevent the production in the spring of spores causing the disease. The investigatory team, made up of Forest Research Institute scientists from Rotorua, has not established the cause of the abnormality, in which the pine needles turn red and drop off. The abnormality has not affected the wood. "We arc reluctant to call it a disease because we have no evidence that it is.” DrSweet said. “But it might be a disease and a new one, and if that is so we would expect

the production of spores next spring. "We decided to get rid of all potential sources of spores next spring by burning the affected areas, to make sure there is no risk of its spreading." Dr Sweet said that at this stage the pathologists' "best guess" was that some fungi normally present in decaying litter had become pathogenic in the climatic conditions in the north this summer, and had attacked the trees. ■ The Northland summer had been the most humid for 20 years, according to weather figures. "If that interpretation is right we would not expect it to flare up anywhere else because the same weather conditions would not apply,” Dr Sweet said. The abnormality was discovered in about 20 hectares of radiata pine forest at Whakapara. about 25 km north of Whangarei, at the end of March. Dr Sweet said the pathologists had been working on the problem since then and would continue to monitor the area till it was burnt.