Disinfected Seeds Avoid Diseases And Ensure Good Crops

Taranaki Daily News, 30 September 1940, Page 20 (Supplement)

Disinfected Seeds Avoid Diseases And Ensure Good Crops

When all is said and done the use of high pedigree seed, the greatest care in preparing the soil and the liberal distribution of fertiliser cannot obtain full production of any crop if the plant itself is weakened by disease. All the cost of first class seed of subsequent cuitivation and of fertilisers may be lost if no measures are taken to protect the crop in advance by killing the disease on the seed. In other words. seed dressing, which before may have been looked upon as a little additional operation which might take place if time permitted, is now recognised by progressive farmers as an indispensable insurance which they can ill-afford to neglect. Modern Metliods. The modern dry dressing method of disease control has now made for itself a definite place in farming routine and the wise farmer would no sooner think of sowing untreated seed than of neglecting all necessary care in the choice of seed or the preparation of the seed bed. It is possible to find, even in very old farming records, references to various methods of seed treatment which were practised in order to protect the crop against bunt or stinking smut of wheat. For years the chemicals used for this purpose were those readily available and they often left a good deal to be desired. Not only was the control of the disease incomplete, but germination damage followed their use. A little over ten years ago a very serious effort was made to introduce to farmers new methods of seed treatment which depended on dry powders which would adhere to the seed. Considerable Research. Tllese chemicals were the result of considerable research and were prepared with special care so that they not only controlled the cereal diseases more effectively than the older chemicals, but did not damage germination. On the contrary, they had a definite "stimulating effect upon the crop so that one of the most striking features noticed by the early users was that fields from treated seed always produced a stronger, greener plant. Farmers were quick to realise that the dry dressings provided them with a very simple method of seed disinfection which could be easily carried out on the farm and the seed could be treated at any convenient time and sown when desired. It was not necessary, as in the case of the old dressings, to sow immediately after disinfection and the treatment could be carried out at any slack period and the seed held in readiness for sowing time. First Dry Dust. The first dry dust to be used was copper carbonate which had previously been employed in Australia with successful results. A few years later, in 1928, the first of the organic mercurial preparations was introduced and the began a movement for the large-scale disinfection

of seed corn. In fact, it is safe to say that until this time no organised seed treatment had been attempted.^ As is now well known, such preparations can be used with great advantage for the control not only of bunt in wheat. but for a variety of diseases of oats, barley, sugar beets, peas and beans, etc. The introduction of a universal dry treatment called for a modification of farm procedure. for whereas the liquid treatment had been carried out in the barn. the most satisfactory dry treatment was obtained when the seed and requisite amount of powder were rotated together in a churn. Churns were assembled on the farm from boxes and old barrels and these machines were found to be extremely effective. An interesting and inevitable development followed "the increasing popularity of this method in that farmers began to demand seed disinfected ready for sowing. While the churn type of machine was, of course, suitable for treating sniall quantities of seed on the farm. the seed breeders and merchants required a machine which would handle a large output in a short space of time. Up to 1929 no effort had been made in England to produce such a machine, but from small beginnines made in that year a number of models have appeared on the market. Continuous Dressing. To-day tiiere is an excellent continuous seed dresser operated by power which provides for an accurate dosing of both grain and disinfectant. Independent tests have shown that this machine is extremely accurate in working, having, in fact, a possible error of only 1 per cent. A feature of the machine is that the whole of the lower half of the mixing drum can be removed bodily to facilitate cleaning out any seed remaining after treatment. In order to give some idea of the development of contract seed treatment by seed breeders and seed merchants, it may be mentioned that at the end of 1930 only sever, British firms were supplying "Ceresan"-treated grain. During the next two years this number had practically doubled. and by 1933 the practice of disinfecting the seed before sowing had increased rapidly so that in that year approximately 150 merchants undertook this work. The expansion and development of this phase of seed disinfection was not limited to England and Scotland, as carefully conducted field tests had proved to the seed merchants and farmers in other countries that seed treatment was extremely beneficial. The practice of delivering readytreated seed has grown so rapidly during the past 10 years that at the present time there are approximately 300 centres in England and Scotland alone where seed treated with one or other of the organic mercurial preparations can be obtained. This rapid increase during the period since 1931 has included a large proportion of merchants supplying "once grown" seed as most of the smaller merchants followed the example of the large seed breeders.