CAWTHRON INSTITUTE

Manawatu Times, Volume XLIX, Issue 3308, 30 March 1926, Page 9

CAWTHRON INSTITUTE

BLACKBERRY AND RAGWORT. TREE PESTS AND DISEASES. NELSON, March 28. Recent activities of the Cawtnron Institute are dealt with in a report to the Trust Board. In the course of the report it is stated that a soil survey of the Walmea County is approaching completion so far as this work can be economically carried on at present. is expected that at an early date a beginning Will be made with a soil survey of the Takaka County. A preliminary examination has been made of a number Of soils from the Collingwood and Murchison Counties, and it appears that a certain type of sheep sickness in the former country is associated with a remarkable shortage of phosphates in the soils Upon which the sickness , occurs.

During the present season field experiments have been continued with barley, grass, lucerne and hay. Tomato experiments have been extended to the field. They have included sterilisation experiments, which have Indicated that chloride o£ llifie, if used with caution may prove to be a very useful soil antiseptic.

Orchard experiments have again demonstrated the great value of Suitable fertilisers. Bath in the appic and peach orchards in the Houtef# hills orchards much attention has been paid to a disorder recognised bji pitting and browning of the fruit, Tlio has been very prevalent this season, and has occurred both in manured and unmanured orchards.

Entomology experiments are being conducted on the control of blackberry and ragwort, mealy bug, pear slug, cottony cushion scale and oak scale, by means of their natural enemies. A large consignment of Canadian green lacewings has been received, and from their eggs a number of adults have been reared. If this lacewing can be established it will be a valuable check to many kinds of aphis, including the aphides of the pine plantations. This type of work is beset with difficulties, and it seems certain that some of the most valuable insects will only be successfully established after repeated trials. Letters of appreciation of the excellent work accomplished by aphelinus mali continue ffco be received.

The trustees hace sent Dr. Tillyard, head of the biological department, to England and America to make a special study of the blackberry and ragwort problem. Other troubles he will investigate are insect pests of pine and spruces, the oak scale and oak aphis and the earwig. The New Zealand Government has contributed £250 and the Commonwealth Government of Australia £IOO toward the expenses of these investigations.

A very large number of diseased plants and fruits from all parts of New Zealand have been received and reported on. Special attention has been given to the study of brown rot in stone fruit, and a paper by Dr. Curtis, illustrated by 50 drawings, has been forwarded to Londop for publication. The paper deals with factors governing resistance to the disease in five varieties of peach, five of apricot, five of plum, two of nectarine and one of cherry. Other fungal diseases treated experimentally have been black spot of apple and die-back and bud-drop of stone fruit. Orchard experiments have shown the advantage of co-operation between the mycologist and the agricultural chemist in dealing with the problems of plant disease. New Zealand fruitgrowers have voted £lon toward the expenses of the biological department.