FARM CROPS.

Press, Volume LXVI, Issue 20083, 12 November 1930, Page 17

FARM CROPS.

VALUE OF GOOD SEED. The farm extension service of the Fields Division and Plant Research Station, Palmerston North, suggests that it would be better, and the cost of production lower, if the best seed were always used. "There are two reasons why the best possible seed is not always used," says the writer. "In -the first place some farmers do not fullj realise the true economv 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 dear seed has not always in the past meant good seed. Hence, some farmers, having used dear seed without obtaining appreciable returns over what would have been obtained from cheaper seed, jump to the conclusion that the quality of the seed does not matter much. Actually, good seed is the foundation of good crops. Pedigree and Performance. "In the second place, those who do know the true value of good seed at times have found it difficult to discover reliable sources ox supply. This difli eulty arises because some of the principal merits or demerits of seed cannot always be detected by inspection of ex- ] ternal characteristics. In other words, j many important characteristics of seeds j are not indicated by their appearance. In this connexion the farm seed position is very similar to the farm livestock position. On every side in the live-stock world attention is being di rected to pedigree and performance. While we are proud of th" achievements of our pedigree stock breeders we are all the time fostering greater efficiency in the work bv 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 arc perennial ryegrass and potatoes. '' Recent developments in respect or potatoes illustrates the economic importance of the official system of cer tification. For years there has been cause for dissatisfaction in regard to supplies of potato seed. It has been difficult to obtan a pure line of many varieties because of the mixing ot stocks. The position has been further confused because the-one variety has received several names or more thnn 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. Scrub Crops.

' 1 Tho general result is that our average potato yield is much lower than it need be. The average Dominion yield is 5 1-3 tons of potatoes an acre, and when it is rc g embered that much of the land sown in potatoes yields from 10 to 20 tons an acre, it is obvious that many misarably low yields must occur. There is abundant evidence that much of the occurrence of these 'scrub* crops os due primarily to inferior seed, and it is to remedy this that potato seed certification is being developed. _ "The need for certification arises from the fact that the characteristics which constitute good seed fali into two principal classes. The first class includes those 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 disease, such as scab or "i 8" The second class includes characteristics about which the appear ance of the 3ced tuber tolls little or nothing. The most important of these is the nresence or absence of obscure troubles, which are known as virus diseases, and which can be detected only by personal inspection of the grow ing plants from which the seed is 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 mav be looked upon as the primary cause of the so-called 'running-out' of potato varieties."