H.—34,

Buildings. The new laboratories for the Plant Diseases Division of the Plant Research Bureau at Auckland were opened by the Right Hon. the Prime Minister on the 25th March, 1939. These up-to-date laboratories and the adjacent experimental area will enable the work of the Plant Diseases Division to be carried out under the best possible conditions. A new building for the Grasslands Division of the Plant Research Bureau at Palmerston North was completed by Ist February and officially opened on 31st March. The building is commodious and well equipped, and being located in the centre of the main experimental area greatly facilitates the work of the staff. Close proximity to Massey College and the Dairy Research Institute is conducive to full collaboration with both. Owing to the fact that the premises in Christchurch occupied by the laboratory of the Wheat Research Institute are required for the accommodation of Government Departments, new premises are being provided by the Accommodation Board for the Institute, and these will, enable the work to be carried out under greatly improved conditions. Good progress was made with the erection of the various buildings required by the Tobacco Research Station at Motueka, three kilns and a curing-barn having been completed by February. Acknowledgment. The loyal and efficient co-operation of the staff in carrying out the programme of work for the year is gratefully acknowledged. DAIRY RESEARCH INSTITUTE. The intensive studies by the Institute on cheese starters were brought last year to the stage at which it appeared that the use of heavy inoculations of single-strain starters under carefully controlled aseptic conditions had solved the problem of starter failures. The occurrence of several unaccountable failures of starters in commercial factories at the beginning of the present season, however, made further investigations necessary. Faulty technique and peculiarities in the milk-supply were eliminated as possible causes of failures. Parallel experiments conducted under exactly identical conditions at the Institute and. two factories then demonstrated that environment must be playing a part, and it was subsequently found that in commercial factories contamination of the starters with phage occurred even when a normal bacteriological technique was practised. The problem then resolved itself into finding a means of preventing air-borne contamination of starters by bacteriophage, and with this object experiments are being carried out in a specially designed starter-room adjacent to, but quite separate from, a' commercial factory. An extensive investigation of the bacterial flora associated with New Zealand cheddar cheese, which has been completed, showed that different strains of lactobacilli produce widely different, effects' in the flavour and texture of cheese. It is therefore important to devise means of preventing organisms which produce undesirable effects from "ganiinjV access to the cheese-milk, and work along these lines is proceeding. ' ' Research on buttermaking included the following projects: The estimation of fat losses in •buttermilk by indirect methods ; factors influencing the oxidation of the fat of butter in cold stordge • the production of diacetyl in starters, and its role in the flavour of butter; factors influencing the hardness of butter. An investigation of land-cress taint in cream and butter, which is prevalent in certain districts of the North Island, led to the isolation of benzyl cyanide as the main constituent of an essential oil steam-distilled from the plant. Mycological investigations have been continued for the purpose of determining the factors causing mould contamination in dairy factories. The resistance to mould attack by different paint pigments and the effects of various paint vehicles have been examined. Promising results have been obtained with aluminium paint, which has been found to offer considerable resistance to mould attacks. In collaboration with the Grasslands Division of the Plant Research Bureau, projects have been continued to determine the food value for milking-animals of certain common New Zealand pasture plants, and in particular to ascertain the effects of these on the production and composition of milk. With the assistance of the Wallaceville Veterinary Laboratory, a study was also made of the influence of continuous feeding of perennial rye-grass, and perennial rye-grass and white clover, respectively, on the health of dairy cattle. The annual dairy-factory-managers' week was held from 2nd to sth May, and was attended by over seventy factory managers and first assistants from all parts of the Dominion. A considerable number of scientific papers were published, or prepared for publication, during the year. PLANT RESEARCH BUREAU. The Plant Research Bureau Committee was strengthened during the year by the appointment of Messrs. C. A. Marchant and Alan Grant as representatives of the North and South Island farmers respectively. These appointments bring the Bureau into a much closer association with the farming industries which it is intended to serve. The Committee, during the year, has had an opportunity to give attention to some of the major problems affecting the pastures and farm crops of the Dominion, and where co-operative action has been required the organization of the Bureau has insured this. The Agronomy Division's trials'with pedigree Liral Crown linen flax havte been continued, and the yields obtained over a much wider area of the South Island have continued to be very satisfactory: Based on this and other information which it has been possible to acquire from small-scale processing trials, steps will be taken to establish a small semi-commercial unit in the Rangiora district during the coming year.

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