H. —34,

of various commercial machine-dressed lines of wheat which had been harvested from crops showing some degree of sprouting : —

The commercial seed from sprouted crops has therefore a lower germination than seed from unsprouted crops. However, the germinations are not unsatisfactory, and the sowing of about 10 lb. of extra seed would compensate for the lower germination. The Effect of Seed Pickling on Commercial Seed from Sprouted Crops. The following table shows that the dry-dust pickles have had little effect on the germination of machine-dressed seed from sprouted crops, but the wet pickles have caused an appreciable decrease :—

Vernalization of Wheat. During the past few years much interest has been aroused by the method of treating seed to induce early maturity, known as vernalization. Under certain conditions, such as exist in parts of Russia, where winter-sowing of wheat is not practised, this treatment has made it possible to grow winter varieties by sowing them, after treatment, in the spring. With a view to testing the process when applied to wheat under New Zealand conditions, seed of Tuscan, Cross 7, and Hunter's was submitted to fifteen, twenty, and thirty days' vernalization — i.e., after the seed had been allowed to absorb water to the extent of 30 per cent, of the dry weight, it was held at a temperature of 0° C. to 5° C. for these periods. The vernalized seed was then sown in pot trials, and also under field conditions, in autumn and spring. The results may be summarized as follows: — (1) Slight increases were observed in field germination of the vernalized as compared with the unvernalized seed, the differences being greater with the longest period of cold treatment. (2) No difference in vegetative development as indicated by height measurements was observed. (3) Vernalization resulted in an acceleration of earing by two to three days with Tuscan and Cross 7 and twelve days with the autumn wheat (Hunter's), but even then the vernalized Hunter's was fourteen days later coming into ear than the unvernalized spring variety (Jumbuck). As a result of this season's observations it is concluded that the process is of no practical value when applied to wheat under New Zealand conditions. If autumn sowing-conditions are unfavourable in Canterbury, there are spring varieties which can be sown and which mature more rapidly than vernalized autumn varieties sown in the spring—e.g., the case of Hunter's and Jumbuck above. Most experimenters are agreed that the main use of vernalization of seed is in border-line cases where it is risky or impossible to grow a particular crop or variety in a given district. In parts of Russia wheat is such a border-line crop, whereas in New Zealand cereal-growing is now reliable. On the other hand, the cultivation of maize and soy-beans in Canterbury is rarely successful. An attempt is being made to find a successful method of vernalizing the seed of these, in order to hasten their maturity. Maize and soy-beans were vernalized (Bulletin 17, Imperial Bureau Plant

82

Percentage of Sprouted T , , « ... n • Sample. Grains in Sample after Laboratory Germination Field Germination Machine Dressing. Percentage. Percentage. (1) Tuscan .. .. .. 10-0 91-0 81-0 (2) Cross 7 .. .. .. 12-0 92-0 80-0 (3) Cross 7 .. .. .. 13-0 89-0 76-0 (4) Tuscan .. .. .. 18-0 86-0 73-0 (5) Jumbuck .. .. 20-0 75-0 68-0 (6) Cross 7 .. .. .. Unsprouted sample 100-0 92-0 (7) Tuscan .. .. .. Unsprouted sample 99-0 90-0

Seed Treatment. Wheat Germination. Barley Germination. Percentage. Percentage. Untreated .. .. .. 79-0 88-0 Hot water .. .. .. 70-0 72-0 Formalin .. .. .. 14-0 40-0 Clark's .. .. .. .. 55-0 82-0 Ceresan .. ., .. .. 79-0 87-0 Copper carbonate .. .. 77-0 88-0