H.—34.

Variety Trials. In the variety trials the flue-cured variety, Moss Special, a variety very similar to, if not identical with, the locally grown variety " Special," was outstanding. Two strains of Hickory Pryor also gave promise of yields above the average. The variety Meadow Giant, obtained from Rhodesia, gave a high yield. This variety is very similar to odd giant plants occurring amongst the locally grown Harrison's Special. All plants have produced at least fifty leaves without coming into flower. Many of the plants are now 8 ft. high. The variety is promising as a breeding-type for crossing with other varieties with a view to increasing the number of harvestable leaves. The leaves of Meadow Giant are rather narrow, and it is desirable to get more width into the leaves before considering it as a commercial variety. In the air-dried variety trials the green variety Maryland Broadleaf was outstanding. Collar-rot Disease. Some trouble has been experienced with the collar-rot organism affecting plants in the field. This disease was confined to the heavier tobacco on the heavier soil types. The fungus penetrated through wounds on the stem and leaves, such as scars where leaves had been picked, in the leaf axils where laterals were removed, topping wounds, insect punctures, &c. The disease was manifested by lightbrown patches appearing on the leaves and stems, the affected parts soon becoming soft and rotten. Infected leaves when placed in the kiln often showed little evidence of the disease, but under the ideal conditions for the growth of the fungus provided by the colouring temperature, when the kiln is kept at 90° F. with a saturated atmosphere, the fungus grew rapidly. The symptoms of the disease spread over most of the affected leaf and generally to all leaves in contact. On removal from the kiln at the completion of the cure, the affected leaf areas were seen as extensive brown, broken-down, lifeless areas, often covered with a white fungal growth. In some cases small black resting bodies produced by the fungus were to be seen around the edges of the affected areas. The highest temperature reached in the curing was not sufficient to kill the fungus, and when the leaf was removed from the kiln again and prepared for bulking, conditions were once again suitable for the growth of the organism. If such affected leaf is bulked the damage can be expected to spread in the bulk, affecting undamaged leaf with which diseased leaves come into contact. Sand-drown of Tobacco. Further tests have been made with dolomite (magnesium-calcium carbonate) and with magnesium carbonate, with a view to the control of a disorder which appeared to be identical with sand-drown of tobacco as reported from the United States of America. The indications of the previous season have again been confirmed, and sand-drown has been controlled in experiments carried out in the Graham Valley by the use of the above-mentioned magnesium compounds. Not only was chlorosis of the leaf prevented, but improvement in the height of the crop, the number of leaves, and the dimensions of the leaf was obtained as a result of the magnesium treatments. The result secured in the Graham Valley, taken in conjunction with the analytical data obtained by the Cawthron Institute in regard to the magnesium content of typical tobacco-leaves, suggests that magnesium compounds may prove beneficial over a considerable area of the Riwaka-Utnukuri tobacco land. Cawthron Institute Report. Soil Survey of Tobacco Lands. The mapping of soils in the Motueka and Kaiteriteri subdivisions, including areas at Sandy Bay and Marakau, has now been completed. Coloured maps showing the extent and distribution of all the main soil types such as sand, sandy loam, silt loam, clay loam, &c., have been prepared, and variations in subsoil texture indicated on the soil types by appropriate symbols. In addition, coloured maps are being prepared showing the distribution of soils suitable for tobacco. The soils have been grouped into four categories in order of suitability for high-grade tobacco-leaf. The area covered by the soil surveys in the Motueka and Kaiteriteri subdivisions is approximately 10,000 acres, of which 1,080 acres were used for tobacco in the 1938-39 season. It is considered that an additional 1,300 acres not at present being used for tobacco are texturally suited for high-grade-leaf production. A fair proportion of this additional acreage, however, is used for hops and small-fruit culture. Tn co-operation with the Department of Scientific and Industrial Research, arrangements were made with the New Zealand Aerial Mapping Co. for the aerial survey of the Motueka and Riwaka districts and the Motueka, Dovedale, and Moutere valleys. A series of photographs on a 20 chain to 1 in. scale is now available for these areas. The photographs will prove invaluable in expediting soil mapping in the Motueka, Dovedale, and Moutere valleys. At the same time, much valuable information concerning the utilization of the land for different crops is provided on the photographs. Soil samples from the different types in the Motueka and Riwaka districts have been obtained, and these are being examined in the laboratory for texture and plant-food constituents. Chemical Investigations. Chemical Criteria and Tobacco Quality.- —With a view to the correlation of chemical composition of tobacco with quality as defined by the manufacturer, a series of samples of Nelson leaf of different grades has been obtained for laboratory tests. In addition, Messrs. W. D. and H. O. Wills kindly presented several samples of high-grade imported leaf to serve as standards in the comparison of analytical data.

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