VIRUS KILLING SWEET BRIAR

Press, Issue 31095, 25 June 1966, Page 8

VIRUS KILLING SWEET BRIAR

Confirmation that sweet briar was dying from a diesease, possibly a virus disease, in the Hakataramea valley in South Canterbury was given this week by Dr. I. D. Blair, reader in microbiology at Lincoln College.

As was so often the case with this sort of phenomenon, Dr. Blair said, it had come to light from an observant farmer. Mr S. M. Hurst, a member of the Lincoln College council, had pointed out to him that on the Table Top property in the valley Mr D. McKenzie, who was an old student of the college, believed that a very substantial amount of briar on his property was dying out It was not just sick—it was going right out. Dr. Blair said that Dr. B. P. J. Molloy and himself were trying to include this in their investigational work. They had been down to the valley and in some areas half the briar plants appeared to be completely dead. There did not seem to be any question

of their being affected by a large number of organisms that were known to affect briar but after which the briar came back and grew just as well the next year. There was a list of about 10 fungi and so on that were responsible for lesions, spots and marks on briar but these disease organisms were strictly of an academic nature.

Plants were being pegged and they would be kept under study when growth resumed next spring. They wanted to know whether these seemingly dead plants would recover or send up new suckers and under what conditions plants died.

On a visit to Molesworth station, Dr. Blair said, he had also seen an area where the briar looked unthrifty—it had a poor colour and leaves that were contracted or buckled. The leaves of these plants were infested with what appeared to be aphides and circumstantial evidence pointed to the possibility that these plants might be suffering from a virus transmitted by the aphides. It was conceivable that the plants which had been seen dead at Table Top , could also be infected with a virus disease.