H.—34,

The buildings to accommodate the Plant Diseases Division, at Owairaka (Mount Albert), Auckland, were completed and officially opened by the Prime Minister, Right Hon. M. J. Savage, and the Minister of Scientific and Industrial Research, Hon. D. G. Sullivan, in March, 1939. The Plant Research Bureau Committee has met quarterly during the year and has continued its function of co-ordinating and promoting research into plant problems in New Zealand. During the absence of the Chairman abroad for the greater part of the year Dr. P. W. Hilgendorf acted as Chairman of the Committee. AGRONOMY DIVISION. Director : Mr. J. W. Had field. This Division is concerned with all phases of crop improvement, and this objective is approached by plant introduction, plant breeding, and pure-seed production. Cereal and Pulse Crops. Wheat.—The production of pure and smut-free seed wheat continues each year to be a useful service performed by this Division. Seed of the following varieties was grown and distributed this past season : Velvet, Hunters, Solid-straw Tuscan, Dreadnought, Cross 7, Montana King, Marquis, and Lin Calel. Oats. —About 112 varieties have been introduced from overseas and placed under trial, and some particularly promising rust-resisting material has been under observation by the Plant Diseases Division. The indications are that Victoria, Bond, Ingold, Green Russian, and White Tartar, either individually or when crossed with one another, are highly resistant, and steps are being taken to utilize these for crossing purposes. A fairly extensive breeding programme is now in its sixth year. There appears to be some useful material arising out of these early crosses, but prospects are more promising in the case of crosses made recently by the utilization of overseas material that has now been tested in this country. Barley. —Investigations in this crop consist at present of plant introduction only. Some forty varieties of malting barley originally introduced have been now reduced to twenty-four for further trial. Particular attention is being paid to feed barleys, and fifty-nine varieties of six-rowed barley are at present under trial. Some smooth-awned varieties show great promise as green feed, coming away more quickly than Black Skinless and recovering after grazing better than Cape. Grain quality and yield appear promising. Field Peas. —The export trade in field peas, which at present amounts to some £150,000 and £200,000 annually, could be expanded if it were possible to produce economically in New Zealand superior quality white peas for splitting and blue peas for boiling. A fairly extensive programme of breeding designed to improve the yield and quality of field peas is now in its sixth year, and trials so far indicate considerable improvement in both yield and quality. This has been attained in some cases by crossing field with garden peas, an avenue which does not seem to have been explored by other workers. Except in the case of the Partridge pea, new introductions have shown no superiority over standard varieties. One variety of the Partridge type is, however, promising. Garden Peas.—The export trade in garden-seed peas is remunerative and worth fostering. Merchants who grow on contract have great difficulty, however, in maintaining the high standard of purity demanded by overseas buyers, and this Division has for a number of years produced nucleus stocks which have been welcomed by merchants to replace their own stocks which have, for one reason or another, become impure. Breeding in garden peas has been limited to a study of segregates resulting from crosses between Greenfeast and Yorkshire Hero, which in some cases have been again crossed with William Massey. Forage Crops. Lucerne. —Two main lines of approach have been developed in the improvement of this crop. The first by the combination of parent plants selected on the behaviour of their inbred progenies. There has resulted a marked improvement in quality, and under single-plant trials an increase in yield of 15 per cent, to 20 per cent, above Marlborough. This strain is now under trial in the field, and an acre has been planted out for seed-production. The second approach has been by the combination of inbred material. This strain is not as far advanced as the first and has yet to undergo yield trials next season. Lucerne is admittedly a difficult crop in which to effect improvement in yield combined with improved quality, and advancement is necessarily slow. Rape.—Marked success has attended the selection work carried out over a period of years in producing an improved rape. Several hundred acres of these new strains are now being grown for seed-production under certification in co-operation with the Department of Agriculture, and New Zealand certified seed is rapidly replacing imported seed. A new strain of rape resulting from a cross between Giant and Broad Leaf Essex back-crossed to Broad Leaf Essex is likely to be distributed commercially in the near future. An attempt to improve on existing types by inter-specific hybridization has resulted in some interesting material. The crosses (Swede X Rape) X Rape and Rape Kale X Rape are perhaps the most promising late-rape t)>pes and have outyielded Giant Rape. Marrow-stem Kale. —Work is progressing in the study of marrow-stem kale with a view to selecting types most suitable for New Zealand requirements. One area has already been sown out for the production of mother seed in anticipation of commercial seed-production under certification.

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