SEED FOR PASTURES

New Zealand Herald, Volume LXIX, Issue 21349, 25 November 1932, Page 3

SEED FOR PASTURES

CRESTED DOGSTAIL

IMPORTANCE OF COLOUR

SUPPLIES FOR EXPORT

Recent work on crested dogstail at Massey Agricultural College lias thrown light on the question of colour in the seed, and it is thought that some of the results may also be applicable to seeds of other grasses. The subject is dealt with by Mr. W. A. Jacques, B.Sc., N.D.A., in the latest bulletin from the college. Until ;recently farmers here and in Great Britain' demanded seed of a bright yellow colour and neglected the darker samples, Mr. Jacques explains. For New Zealand renditions this bright seed appeared satisfactory, as the germination was high. When exported to Great Britain, however, it was found that it lost a portion of its germination capacity en route, and in some cases this loss was considerable. It was found that samples of darker colour could withstand shipment better than the seed of a lighter colour. This in itself suggested a greater vitality and a more perfect state of maturity, and the results of the trials confirmed this opinion. In crested dogstail that is harvested normally and stored rationally seed colour can bo regarded as an indication of the maturity or ripeness of the grain. As the maturity progresses the green colour gives place to greenish yellow and then to colours darker than yellow, and the final colour so attained varies with the different plants. Some plants produce seed which never becomes darker than orange brown; others produce seed which is almost black; while between these two there are many intermediate colour stages. Relation of Colour to Germination

When seeds are tested at the official seed-testing station at Palmerston North a certificate is issued showing the percentage of seeds which germinate in eight and 18 days. The 18-day figures represent the final count in the germination test and are quoted by the seedsmen when giving the germination capacity of that particular line. In practically all cases the golden yellow samples give a high figure, and for New Zealand conditions at least appear satisfactory. It is only after consideration of the eight-day figures that their weakness is apparent.

The interim (eight-day) count shows that actually such seeds are immature and have a much lower vitality than seeds which have developed sufficiently to attain the brown colour. This in itself may not bo a serious drawback under New Zealand conditions, but this lack of vitality is one of the causes which are undermining the demand for New Zealand seed abroad. It is fortunate for New Zealand that Ireland, her main competitor in the English market, has a poor climate for seed production and frequently has only unattractive samples to offer. In a current year's seed catalogue sent out from England, New. Zealand dogstail seed is offered at the same price as Irish seed (Is 3d), but the germination figure is 10 per cent lower than the Irish seed. This in itself is sufficient to reduce the demand for the New Zealand seed.

It thus devolves on the Dominion growers to produce an attractive sample, which has the requisite high germination capacity. This can only be attained by allowing the seed to become more mature. The crops should be cut at a stage which will give a light brown seed sample; this will still be attractive. and pleasing in appearance, and what is more, it will be an excellent product.

Relation of Colour to Seed Weight As colour deepens, so does the individual seed weight increase, continues Mr. Jacques. It was found that brown seeds were 20 to 33 per cent heavier than the canary yellow seeds from the same plant. This not only indicates a better filled seed, but also a greater food reserve, which will enable the dogstail to withstand better early competition in the pasture. To some extent it compensates for the loss which occurs from shedding due to. allowing the crop to stand longer before being cut.

When everything is considered, the balance is very njuch in favour of the darker seed, providing it has been well stored. Where "stripped" seed has been allowed to heat, frequently extremely dark samples result, and thoso naturally should be regarded with suspicion. The critical test is vitality and germination, and these should be considered before any other factor.

It is not intended to convey the impression that with the purchase and use of the best seed all dogstail problems are solved, but it does mean that by so doing the best results can be expected from the material that is at present in commerce, and that the Home samples of New Zealand seed will at least compare favourably with those produced in Ireland.