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MISCELLANEOUS Legume Culture.—Lucerne culture for 362,0001b. seed has been sent to 2,757 growers. This represents an increase of 13 per cent, in quantity of culture and 9 per cent, in number of growers over the previous highest figures (194849). A few cultures for white clover, subterranean clover, and soya-bean have been distributed. Factors governing growth of clovers in glasshouse have been investigated and trials on relative efficiency of clover-nodule strains are now in progress. A few field trials, under supervision of Extension Division, Department of Agriculture, are being carried out. Yellow-leaf of Phormium Flax.—Field investigations have been carried out at Moutoa Estate, Bay of Plenty, Wairarapa, and North Auckland. In all cases observations were made on diseased and healthy flax to determine more exactly symptoms of the disease, particularly in the early stages. Approximately 1,000 isolations have been made from diseased flax roots, but as yet there is no indication that any one or more fungi or bacteria are the direct cause of yellow-leaf. Pathogenicity tests with the most consistent or possibly pathogenic fungi have yielded negative results. Other tests are in progress. A mechanical transmission trial has been set up at Moutoa on highly susceptible flax seedlings to test possibility of virus infection. Axillary bud and root grafts for possible virus transmissions have been attempted. Other diseases of phormium, often closely associated with yellow-leaf, have been investigated. These are summarized as follows: Gloeosporiu/m sp. causing seedling blight in glasshouse, and central shoot-rot hastening complete collapse of yellow-leaf-infected plants; two species of Fusarium causing central shootrot, scape damage, and large leaf lesions; and soft-rotting bacteria associated with above. Inoculations with above organisms are at present in progress. Fruit-fly and Fruit Imported from South Africa. —A report on the citrus investigation carried out in South Africa in 1948 was prepared and circulated to interested people. As a follow-up to this an endeavour is being made to arrange experimental shipments of oranges and grapes under cold storage from South Africa to New Zealand this season, and it is hoped the data obtained will allow experimental shipments in 1951. The co-operation of South African authorities in this work is being sought. jEuropean Wasp.—Work on the European wasp is being carried out mainly in the vicinity of Hamilton. It has been shown that the application of DDT to such trees as oaks, the aphis honey-dew on which attracts large numbers of queen wasps, is not a feasible method of control owing to adverse effect on honey bees, which are also attracted by the honey-dew. Particular attention is being paid to an investigation of the economic importance of the European wasp. The only fruit that appears to be damaged is the home-grown grape, which is frequently left on the vines until it becomes very ripe and soft. Work is being carried out on the biology and distribution of this wasp and on its control by the use of bait traps. House-fly Control.—Trials with house-flies collected from certain localities in Auckland have shown that strains resistant to DDT have developed. Work with resistant and susceptible strains has shown that the insecticides benzenehexachloride and chlordane are equally toxic to DDT-resistant and DDTsusceptible flies. Tests indicate, however, that DDT-resistant flies are also somewhat resistant to Compound 497 and DDD. Tests on toxicity of benzenehexachloride have been commenced. The effective life of residues on glass and painted wooden surfaces is also being determined.

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