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The turnip Bruce has proved moderately resistant in the South Island. While selected resistant strains of rape have shown distinct promise, work in this connection has not proceeded beyond preliminary trials. It has been found that a practical control of club-root could be secured on land moderately affected, by the application of 33 cwt. of burnt lime applied three months in advance of sowing the crop, followed by drilling with the seed basic slag or with a mixture of equal weights of superphosphate and slaked lime. It has been found that club-root spores will remain in a live condition in the soil for at least three seasons, and that weeds such as shepherd's purse may act as host plants during this period. 11. Cereal Diseases. In view of the need for cleaning the wheat variety Jumbuck of smut disease, it has been found that a modification of hot-water-treatment method will be necessary, as this variety is very susceptible to germination injury when dealt with by the standard methods. Trials are in progress with copper carbonate and organic mercury compounds in order to test out their efficacy as controllants of smut disease. Studies of the biotypes of cereal rusts present in the Dominion have been commenced as a preliminary to the production of more resistant types of cereals and grasses, as it is considered that protection from these diseases cannot be secured by any form of chemical treatment. 111. Potato Diseases. Work on the wilt diseases of potatoes has been completed, and four years' investigations have revealed the presence of fifty types of fungi, very few of which, however, were actually responsible for the wilting of the haulms. A report on the work will shortly be published. Internal brown-fleck disease, common in Northern Star and Victory potatoes, has been investigated, but the work has not been productive of any conclusions, except that tubers grown from infected seed show a marked tendency to development of the trouble. A small line of virus-free potato-seed, covering four varieties, is now being grown in a selected area for the purpose of providing virus-free seed for commercial distribution. IV. Diseases of Legumes. Collar-rot of peas has now definitely been proved to be a seed-borne disease, which does not persist in the soil for more than a limited period, and that crops free from the disease can be secured by the use of clean seed. Steps are being taken to provide nucleus lines of such seed. Bean wilt has been largely controlled by a method of seed-treatment, but further investigations are yet necessary to render this control more complete. Sore-shin of lupins has been investigated by treatment with various chemical disinfectants, but no satisfactory control has yet been devised. The demand for lucerne cultures has shown a marked increase during the year. A sufficient quantity of the culture has been distributed to inoculate 69,500 lb. of seed, an increase of 80 per cent, over the previous season. These cultures were forwarded to 1,037 farmers, an increase of upwards of 40 per cent, over last season. Attempts are being made to extend this work to cover the nodule organisms occurring on white and red clover. V. Cheese and Butter Moulds. Work has been commenced on the various moulds connected in particular with discoloration of cheese and butter. VI. Forest-tree Diseases. A disease survey of the exotic plantations of the State Forest Service was conducted during the year, and it was found that Phomopsis Strobi was located on Pinus radiata regions subjected to severe winter conditions. Diplodia pinea was found to be responsible for serious losses in seedling Pinus ponderosa in nursery-beds. This disease also was in evidence in young stands of various pines, when unfavourable conditions were experienced following planting, and in older trees where unseasonable frosts were experienced. Another form of Phomopsis was found to be responsible for serious losses in nursery stock of Cupressus Lawsoniana and C. Macrocarpa. VII. Fruit-tree Diseases. Detailed chemical investigations and orchard trials have been carried out during the year with specifics containing sulphur, lime sulphur, and copper. As the result of these experiments many orchard-spray practices have been profoundly modified and useless sprays discarded. In the field-work some five hundred experiments were conducted with a view to testing out different sprays and spray practices. Other investigations have been made into fruit-tree canker and in regard to fungous diseases in cold stores. Investigations of the strawberry disease have revealed the presence of a serious virus in New Zealand. Consequently attempts are being made to raise virus-free strains of these plants. Five different diseases of tomatoes are also under investigation.

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