H.—29

" An experiment at Mamaku State Farm confirmed the superiority of chlorate compared with dichromate, thiocyanate, and bisulphite weedkillers. Another Mamaku experiment is designed to determine the effect of treatments on individual plants at various times throughout the year and the toxic dose per plant. Progress reports indicate that the amount will be about 3 grams or 4 grams. Plants in Ruakura pasture have been completely killed by 5-gram doses. " Experiments in the Ruakura nursery indicate that injections of chlorate into the soil or applications on the soil surrounding the plants are not as effective as those applied to the foliage in the usual way, that dilution of the spray has little effect and that the seed from flowering plants sprayed with 2| per cent, and 5 per cent, sodium chlorate has a germination of 10 per cent, to 20 per cent., compared with 50 per cent, to 80 per cent, in unsprayed seedheads." Samples Received for Analysis, 1938-39. Wellington Laboratory — Pastures for trace elements .. 448 Thyroids .. .. .. 8 Animal organs for trace elements 137 Dips .. .. .. 5 Pastures for mineral analysis, &c. 281 Limonites .. .. .. 2 Toxicological specimens .. 248 Miscellaneous .. .. 109 Milks and urines (arsenic 2,609 investigation) .. .. 121 Ruakura Laboratory — Stock-foods .. .. 32 Pastures— Pig-fats .. .. 56 Fields Division plots .. 404 Butters .. .. .. 141 Facial eczema —general .. 301 Fertilizers .. .. 53 Facial eczema —rate of growth 102 Soils .. .. .. 491 Soils— Limestones .. .. .. 150 Facial eczema —moisture .. 202 Field crops .. .. 49 Facial eczema —nitrate .. 162 Sugar-beets .. .. 11l Ragwort .. .. 14 Waters .. .. 84 Viscera .. .. 22 Stock-remedies .. .. 10 Curds .. .. .. 15 Seaweeds .. .. .. 13 1,222 Canterbury sheep survey pasture extracts .. .. 60 Total .. .. .. 3,831

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