LIVE STOCK AND THE FARM

Southland Times, Issue 18937, 25 September 1920, Page 7

LIVE STOCK AND THE FARM

Powdery fcah of the potato, although not usually accepted as the cause of serious loss to this crop, is attracting considerable interest in this country, as it is from its presence in New Zealand that the Commonwealth placed an embargo on the importation of our potatoes into Australia. In older lands this dtsea.se is of fairly wide distribution. The actual extent of that distribution in this country is not actually known, but is probably present over a fairly large area. It is readily confused with other types of what are popularly accepted as potato scab. This form of potato disease appears to he specially associated with undrained lands and districts of heavy rainfall. In Great Britain, where it is present, there is but little apprehension of damage to the crop in the districts where the soil and climatic conditions are favourable to potato growing. The disease is caused by the minute organism known as Spongosponnn subterranea. It is of the group of fungi that causes club-root in turnips- and in other plants of that order. In its first appearance it is shown by small irregular rough spots on the skin of the tuber, these income, rounded raised patches, later the skin breaks, finally an open canker is exhibited, and with this through the action of the fungus the surface of the tuber next to the skin becomes hard. From this comes the popular name the corky scab. At the reproductive stage of the organism small brown bodies known as spore-halls are former!. These balls are held together in a sponge-like mass. 'I he spore-halts are microscopic. they appear under examination as masses of brown powder; this is liberated when the tubers are lifted. It is from the presence of this powder that the disease is known in many countries as the powdery scab. The parasite does not confine itself to the tuber; it extends the invasion to the fibrous roots of the plant, where, nodules are formed, that assume the appearance of those of bacterial origin on the plants of the pea family. The disease is extended to uninfected areas by the spore-balls. These are readily disseminated over the surface of the soil in the process of lifting affected crops. The contamination to the succecd- | ing crop is manifested by the outbreak of disease in adjoining areas; this may occur even in those that arc situated at a distance from the land wlk re the affected crop was grown. It is not definitely ascertained for what length of time these spores retain the power of reproduction; it is, however. fairly assured that vitality remains unimpaired for three years. There is the general evidence that the infection docs not entirely disappear from a contaminated soil for at least five years. 1 his disease is also found on other plants of the potato family, I* will ire easily understood to what an extent sod may become contaminated; the .'•pore-halls under suitable conditions of temperature and moisture germinat-c rapidlv, each-minute grain or part of the spore-ball produces still smaller spores. A single inf'Tted plant may produce hundreds of thousands of spores or seeds for further infection. The direct extension of affected areas is chiefly due to the use of diseased seed potatoes; the spores that arc present on these germinate and affect the crop that is grown from the infected tuber;. The selection of seed potatoes where the disease does not exist is the more effective precaution than tlie treatment of affected tubers. The disinfection of shghtty atfceied seed is onlv reasonably satisfying. Hie treatment recommended is that of sleeping in a solution of formalin. An alternative method is that of first, moistening lire {gitato and covering with powdered sulphur, popularly known es flowers of sulphur. The formalin or sulphur steep provides effective treatment for lightly affected tubers. The use of copper sulphate preparation is also a successful disinfection, but attended with injury to the cron. It is claimed that the application of lime to the soil increases the seriousness of the disease; it is somewhat, curious that, tms is so. The organism is of the same group that is the cause of club-root of the turnip, and lime is accepted as almost, a. panacea, or specific remedy, for the affect ion of that plant. Ihe potato is. however, resentful of lunr. It is well known that the duality of the tuber is affected by its application. The chiel precautions are the use of dean seed, careful disinfection if it is necessary to make use of lightly affected potatoes for seed, and well-drained soil. The loss of c-rop from oilier diseases of the potato artbeing overcome by the introduction of immune varieties of the plant or of those that possess a strong resistance. So far. however. no variety has been recognised as im--1,1 uue or resistant to the p-owderv smb of the potato.

In ,\ew Zealand (hr pasture occupies a far greater area in proportion to that, dryoterl to crops than is usually known in countries. It is quite natural that this should he the position, for the plants of our pasture.- have a longer season of growth, tuan those of most other countries" The pastures of New Zealand are its greatest rtehrs. Tie question may, however. he asked, tire these pastures in the best eon .'i ttou'f It is believed that it will he accepted | that, the reply cannot he in the affirmative. I Many of these pastures remain' undrained, j tir hut little attempt has hceu made to re[move surplus water. This is a condition I I oat is advor.se to the greatest production of herbage am! even prohibitive to (he pres, enre of many of the most desirable varieties of grasses and clovers. It is fully admitted that the, cost of draining is a serious item to consider; still the improved condition of the pasture is a warrant for the undertak- | mg, and there are few pastures where dramI lnr - ] ,s wtitiled that will fall to repay the joutia}. within a reasonable time. The a-dvan-Ifiges are immediate and numemus. the pro jducMon Is greater, (!, e belter varieties of ] gras-es and Igumrs may be grown, the sea [son is lengthened, ami moat of all, the very reason of the existence of pastures the maintenance of live stock in a thriving con .ration is secured. In the well-drained pa--lute the parai-itcs that. afTeet the animal t;id to not,am a favourable habitat in the water logged soil, and eerlain diseases are forniLfiaole on the wanner well-drained faniis. It cannot fail to be recognised that held drainage should receive much greater attention; in tact, the increasing price of laud will enforce improvement. The rushcovered water-saturated country may have been permitted, when the unearned' increment was the most secure and profitable production of the farms of New Zealand. That increment nitty be accepted as becoming le-'s as-u;orl and very decidedly of a lest rapid harvesting. The improved condition of the laud is a necessity 0 f ,j lc t , re:;cn p aU( t ( i 1() first step to that is drainage. There are other improvements also tc be undertaken. There i'-, on the great proportion of grass lands, the all-essential lime to be liberally applied. With this there are the usually accepted fertilisers lo be used. To these the plants of the pasture respond in actual proportion In the extent of the apulic.atinn. an I. the Ihe stock participates with the favourable coudit’ons of t.hc sod to rapidly affect the desired aherahrm in l lie pasture. The do vets from forming but a small part of the herbage, bee rune the greater. With this the animals thrive better, and the greater stock-carryin capacity of the pasture, is quickly manifested, and with this, the greater the abundance of the clover, the greater the quantity of nitrogen that will he obtained and the greater fertility of the soil is secured. If has to be accepted that there are soils and conditions that may not be amenable to the treatment required to admit white clover to become abundant. It is in such circumstances that atsike becomes useful. This variety is. of course, well known but it is not possibly such general knowledge that it will grow on soils too acid, too wet and too poor to be acceptable to other clovers—it has been known to withstand a winter season that destroyed both grasses and white clover. ALsike comes from the North of Europe. It was railed Swedish clover, and named aisike from the district

POTATO DISEASE. Grassland Improvements. BY “HARVESTER.”

from which it was introduced into Great Britain. It is also catalogued as a hybrid. Later botanists consider it a separate species and the plant as we know it has been a thousand years in cultivation in its own country. Its introduction into other lands docs not date back to more than a century. Ibis clover should he associated with the grasses that are not in the highest esteem as certain varieties of the fescue or port and with those of the agrestis tvs florin and others. Alsikc clover is valuable with those where white clover would fail. This last thrives with ryegrass, cocksfoot and timothy. With these the less discriminating alsike should have a place. It responds generously to the better conditions and with white clover is as great a value in the most productive pasture as the white variety, even as grant ns the widely advertised wild white one. White and alsikc clovers are valuable plants in (he herbage of the oasture. The capacity is indicated' in proportion to their abundance. Experiments on the improvement of grassland carried on by the Northumberland County Council at the County Agricultural Experimental Station at Cookie Park, arc now in their twenty-fourth'year and present some wonderful results. Tree Field—-a poor stiff clay, at no time worth more than 10/- per ar-te and worth 2/6 per acre when taken under experiment --has been manured tor mutton in these years, ten different methods of treatment having been tried. The most profitable has been the application of basic slag in Klewt per acre doses, these doses being given in 1897, 1006, 1012, and 10IR, i.e., a total of -iOcwt of 30 per cent, basic slag. During this period the sheep on (he plot so treated have put- on 20051b more live weight increase than the sheep on the untreated plot. Allowing for the fact that the full value of the slag applied in 1918 has not yet been obtained then the extra live weight increase of 20051b has been obtained by the use of 33cwt of slag. It is estimated that for every shilling spent or. slag a gross return of S/- would follow. Even more striking results have been obtained on Hanging Leaves Pasture Fields—of the samp soil as Tree Field. Whereas 3 ree Field has been pastured with shoe!' ofily, i[anefing Leaves J-ields have been

Mocked with both cattle and sheep. Plot. 1 of the latter fields compares with plot -1 of the former, both having received slag alone since 1597, in the same quantities and at about, the same dates; in each rase the last dressings of Hag applied wore srwt an acre for 1906, 1909, 1912, 1915 and 1918. For the eleven years 1909-1919 the average an nual gains per acre were 101 lb on Tree, field plot, pastured with sheep alone and 1921b on the Hanging I,eaves Fields plot stocked with both cattle and sheep. There can be no doubt that much belter results are obtained when pasture is grazer! with a mixed stock of cattle and sheep than when grazed with sheep alone. In the years 1912-17 the results from application of the slag in Tree Field in the summer were compared with application in the autumn following; much belter gams wort 1 made from tiie summer application. It has further been found disadvantageous to apply the slag at a time when heavy rain is likely to follow. It has been repeatedly noticed when this is done that heavy rains tend to collect, the basic sing applied to the land, into irregular lumps, and much of the slag may he carried away. particularly on sloping ground, owing to. the ittrge amount of water running from the surface.