AVON WILLOWS.

Press, Volume LXVI, Issue 20083, 12 November 1930, Page 11

AVON WILLOWS.

ATTACKED BY BLIGHT.

DANGER OP ERADICATION. j It is the opinion of Mr E. B. Owen j that the willows fringing the Avon are j doomed owing to the ravages.of parasites in the form of beetles, grubs, and green fly, which have attacked the trees, some in the circulatory system and others in the leaves. 1 Speaking with a representative of Ihe Press last nisjht Mr Owen said that three years ago he first noticed that damage was being done to a willow on the banks of the Avon near the Canterbury Club in Worcester street and drew the attention of the Superintendent of City Parks and Reserves to it soon after that officer took up his duties in Christchurch. It was a beetle in' this case which was responsible for the damage. The insect had done its deadly work so well that the willow was now in the final stage of its existence. Another tree near the Bridge of Remembrance was also in a bad state, being riddled with beetle holes. Further down the stream, near Barbadoes street, Air Owen had that day seen myriads of green flies slowly climbing up the bole of & tree, making their way towards the young leaves. Ihis year blight in its various forms appeared to be particulariy bad, as in addition to willows being attacked such trees as the bluegum, oak, rowan, and silver beech were being subjected to the attention of the pests he had mentioned. In Hagley Park there were numbers of oaks which were dead from the effects of golden scale, which was very active this year, other trees being in a moribund state. In his opinion most of these trees could have been saved had the City Council purchased powerful sprayers when their attention was drawn to the matter some years ago. Similar conditions obtained' in other countries but the pests had been kept in check by the use of sprayers, aeroplanes, and even fire engines.' Mr Owen said that unless Chrißtchurch woke up to the position there was a j:rave danger of its losing a great i.i.al of it 3 present charm, which was its beautiful trees. Christchurch without its willows along the -Avon would not be Christchurch. Whije something might yet be done to hold the pests mentioned in check he was afraid that it was too late to save more than a certain proportion of the willows. No Cause for AlarmWhen statements regarding the alleged widespread disease amongst the City's Aces were submitted to Mr James Young, Curator of the Botanic Gardens, he told a representative of ihh Pi.Es.j that there was no cause for alarm. As to the City's willows, Mr Young said that the trouble with them was old age. Some of them were fifty or sixty years old, which is about the average life of the willow. Some old willows ' that have had to be cut down were found not only to be hollow, but also rotten. He quoted from an authority on tree diseases, who set out: "In general very \ittle attention has been paid to willow diseases because of the slight economic importance of the trees." The Avon willows, Mr Young said, were beautiful, but the only thing that could be done was to replace old trees with young ones. As to the British oak, Mr Young reiterated his frequently expressed opinion that neither the climate nor the soil in this part of Canterbury is suitable for . its growth. In England the oaks that have attained great ages, three, four, or five hundred years, were growing on land with a heavy clay subsoil, which retained the moisture, and enabled the trees to become firmly rooted. His observations went to show that golden scale was not increasing on the oaks in the Botanic Gardens, and in some instances it had been got rid of. He bad recently liberated on aome trees affected a number of Habrolepis dalmanni, a consignment of which he_ had received from the Cawthron Institute last week. Some time ago ho had discussed the question of the means to be adopted for the eradication of golden scale with Dr. J. R. Tillyard, who was at the time chief entomologist at the Cawthron Institute. Writing on August 10th, 1927, Dr. Tillyard thus expressed himself: "I am most strongly in favour of your own solution, viz., to grow other varieties, like Turkish and American oaks which are immune to theße blights." Mr Young added that as long as he had any say in matters, no more British oaks would bo planted in the Garden?. As 'to the idea of spraying forest trees, Mr Young ridiculed it, and said that it would be warranted only in the case of any specially valuable tree.