FARM EXTENSION SERVICE

Manawatu Standard, Volume L, Issue 245, 11 September 1930, Page 4

FARM EXTENSION SERVICE

SEED CERTIFICATION, A NEW AND IMPORTANT AID TO BETTER-CROPS. The farm seed position is one of importance and difficulty. Our crops would be greater and our cost of production lower if the best possible seed were always used. There are two main reasons why the best possible seed is not always used. In the first place? a section of our farmers do not fully realise the true economy of good seed. This may be due partly to the fact that high price is naturally expected to be reflected in good quality in seed, whereas actually clear seed has not always in the past meant good seed. Hence, some farmers having used dear seed without obtaining any appreciable returns over what would have been obtained from cheaper seed jump to the conclusion that the quality of the seed does not matter - so much. Actually, good seed is the foundation of good crops.

In the second place, those who do know the true value of good seed and so desire to use, at times, have found it difficult to discover reliable sources of good seed. The difficulty in this respect arises because some of the principal merits or demerits of seed cannot always be detected by inspection of external characteristics. In other words, many important characteristics of seeds are not indicated by the appearance of the seed. In this connection the farm seed position is very similar to the farm live-stock position. On every side to-day in the live-stock world we have attention being directed to pedigree and performance. Rightly tens of thousands of pounds annually are being spent in this sphere. Rightly while we are proud of the achievements of our pedigree stock breeders we are all the time fostering greater efficiency in the work by such national movements as semi-official testing and herd testing. The point that we have been overlooking in the past is that in the seed world there is much profitable scope for similar endeavour involving the production and the use of pedigree seed. It is this that has led to the introduction during recent years by the Department of Agriculture of seed certification. Up to the present two of the most important lines of seed to which certification has been applied are Perennial ryegrass and potatoes. Recent developments in respect to potatoes will illustrate the economic importance of the official system of certification. For years there has been much cause for dissatisfaction in refard to supplies of potato seed. It aSf been difficult to obtain a pure line of many varieties because of the mixing of stocks. The position has been further confused because the one variety has received several names or more than one variety has received the same name. Further, even when the desired variety of seed was secured there remained much doubt about its cropping powers for different lines of seed of the one variety differed greatly in producing powers. _ , ; ■ The general result is that our average potato yield is much lower than it need be. The average Dominion yield i 9 5 1-3 tons -of potatoes an acre, and when it is remembered that such of the land sown in potatoes yields from 10 to 20 tons an acre, it is obvious that many miserably low yields must occur.

There is abundant evidence that much of .the occurrence of these “scrub” crops is due primarily to inferior seed, and it is to remedy that that potato seed certification is being developed. Recent instructive developments in

(Contributed by Fields Division and Plant Research Station.)

potato seed certification are described ■in an article by J. H. Claridge in the August issue of the Journal of Agri-cultui-e and so only main features need be mentioned now.

The need for certification arises from the fact that the characteristics which constitute good potato seed fall into two principal classes. The first class includes ones which may be judged from the appearance of the tubers, such as the ( purity and maturity of the seed, the 'size and shape of the tubers and freedom from such diseases as scab and late or Irish blight. The .second class includes characteristics about which the appearance of the seed tuber tells little or nothing; The most important of these characteristics is the presence or absence of obscure troubles which are known as virus diseases and which cah be detected only by pei - sonal inspection of the growing plants from which the seed are obtained. The. virus diseases, which include such troubles as mosaic and leaf roll, have not received much attention in New Zealand until recent years. They may be looked upon as the primary cause of the so-called “running out” of potato varieties. How the presence of virus diseases influences cropping power is strikingly indicated in Mr Claridge’s article which has already been mentioned. Last season’s official trials with Dakotas provide the evidence. Ninety-seven lines were tested, and as the yield went down the amount of virus infection correspondingly went up. The main facts are:—

(I) Lines yielding 10 or more tons an acre showed a virus infection of 7 to 16 per cent. (II) Lines yielding fi - om 9 tons 18 cwt. to six tons an aci - e showed a virus infection of 18 to 33 per cent. (III) Lines yielding from 5 tons 18 cwt. to 3 tons an acre showed a virus infection of 37 to 61 per cent. (1Y) Lines yielding from 2 tons 18 cwt. to li tons an acre showed a virus infection of 68 to 94 per cent. In biief, the greater the amount of virus the less the yield.

The above facts are not to be taken as an indication that Dakotas stand out from other varieties because of an unusually heavy infection with virus disease. A table given by Mr Claridge dispels the possibility of such a misconception. In this table it is indicated that, of the lines which remain after rejections had been made on account of the presence of “rogues” or impurities, 55 per cent, of the. Dakotas were rejected because of the presence of virus or deficient cropping. From this the Dakotas certainly seem to bo in a pretty bad way until it is noted that for the same reason the rejections for other well known varieties amounted to 76 per cent, in the case of Arran Chief; 78 per cent, in the case of Up-to-date; 77 per cent, in the case of Majestic, and 75 per cent, in the case of Northern Star.

A convincing indication of the need for certification is provided in the striking differences which occur in the yields of the lines which are grown in the trials. It. may be assumed that the owners of all these lines considered that their potato seed were of more than average merit; otherwise they would not have taken the trouble to seek certification for them.. Further, it is necessary to bear in mind that all lines entered for certification are grown under similar conditions of soil and treatment under official supervision. The yields that are published axe the ones which are obtained under such uniformity, and so all differences which occur may safely be put down as due to differences between the lines of seeds themselves.

Her© are some of the differences which occurred in last year’s 1 official trials under such uniform conditions:—

Dakota ranged in yield from 11 tons 12 cwt an ; acre to 1 ton 14 cwt.

Aucklander Short Top (often called Sutton’s supreme) from 14 tons 8 cwt. to 3 tons 2 cwt. Arran Chief from 10 tons 12 cwt. to 2 tons 4 cwt. Up-to-Date from 11 tons 5 cwt. to 2 torus 2 cwt.

Epicure from 9 tons 14 cwt. to 10 cwt.

Jersey Bennes from 6 tons 8 cwt. to

1 ton 12 cwt. an acre. •' Similiar differences occurred in the case of other varieties. The truly significant feature of all this is that it was deemed worth while to seek certification for so many deplox-ably low yielding lines. And from the fact that they wei - e submitted for certification it is probable that somewhei-e seed of similar breeding and origin is being offered commercially. From what has been said it will be seen that the yield from certified seed may reasonably be expected to be superior to that from .ordinary seed. To obtain definite evidence on the point, Mr J. W. Hadfield, agronomist, last season organised special trials in' which certified and non-certified seed were grown side by side under similar treatment at six centres in Canterbury and one in Southland. The i - esults of these trials were Epicure certified seed yielded an average of 3 tons 2 cwt. more than Epicure non-certified Aucklander Short Top (Sutton’s Supreme) certified yielded 18 cwt. an acre more than Aucklander Short Top noncertified ; Dakota certified yielded 3 tons 6 cwt. an acre more than Dakota non-certified; Up-to-Date certified yielded 6 tons moi - e than Up-to-Date non-cei-tified. Further information on the samo point is piovided by last year’s trials with the Dakota lines sent in by owners seeking certification; the yield of the lines which became entitled to certification was 8.5 tons an acre, while the yield of the lines which were refused certification was 5.7 tons an acre. How what might be called “pedigree” counts in potatoes is indicated from the i following results of the 1929-30 trials: 102 crops'under the trial originated from certified seed or provisionally certified seed; of these 57 mei'ited certi- : fication. 263 crops under trial originated from , seed which had not been certified; of : these .53 mei’ited certification. That < means that when dealing with crops i from certified seed rejections amounted I to 44 per cent, of the lines submitted, ! whereas when dealing with crops from 1 non-certified seed the rejections 1 amounted to 80 per cent, of the lines i submitted. From all this there i are three definite conclusions:— i (1) The use of certified seed is very i likely to result in substantially heavier f crops.

(2) The use of certified seed is generally the most direct way towards enabling one to become the producer of certified seed.

(3) The use of certified seed does not- ensure that the “seed” from the resultant crop will itself be entitled to certification. Last year approximately one out of every two crops from certified seed was rejected for certification purposes. As might be expected, because of its intrinsic value the work of potato seed certification is showing remarkable growth in popularity; in 1927-28, 137 lines were entered; in 1928-29, 180 lines; and in 1929-30, 408 lines were entered. *

Ordinarily, certified potato seed is more costly than ordinary seed. Buyers may protect themselves, and should protect themselves, by making -sure that the “seed” which is supplied as certified seed is from sacks which carry the official tags which are issued to growers of certified seed in sufficient number. to enable one tag to be attached to each sack of seed which ha 9 passed the final examination entitling the seed to certification. At the present time the seed is being sold as “entitled to. certification” or “provisionally certified.” This seed is in sacks to which the official tags are not attached, and if buyers of it find themselves in possession of an inferior line they have only themselves to blame because of their disregard of the official safeguard which is provided by the tag on the sack.

To sum up, to be on the safe side as regards procuring certified seed the buyer should see that tho official tag is on the bag. If there is no tag, the seed is not certified.