FUTURE PROGRESS

New Zealand Herald, Volume LXXIV, Issue 22670, 6 March 1937, Page 12

FUTURE PROGRESS

SPREAD OF RAGWORT PROBLEM TO BE SOLVED COSTLY CONTROL METHODS BAY OF PLENTY HILL AREAS No. XII. BY H.B.T. •The spread of ragwort presents tho biggest single obstacle to the successful development of the Bay of Plenty hill country to-day. Many settlers, and especially those who have been more or less unsuccessfully combating its spread during recent years, are inclined to consider the problem a hopeless one where the unaided farmer, with a considerable area of broken country to combat, is concerned. As soon as the bush is felled, burned and grassed this unwelcome interloper makes its appearance, and unless the country is immediately heavily stocked with sheep—which injure the young and lightly-rooted grass —the area iB soon smothered with the weed. From roadsides, unoccupied native and Crown lands and newly-burned country it spreads tc. established pastures, gaining'a hold sin even comparatively dense swards. Need for Capital The toxic effect of ragwort at certain seasons on sheep, and its deadly effect on cattle, make its control by the usual methods of stocking most difficult. Only a landholder with considerable capital, who can afford to buy large numbers of stock, especially sheep, at periods of the year when their grazing will keep the plants from flowering, and who can sell these and replace them with others before the effects of the drug which the plant contains seriously affects their health, can hope io keep the land even reasonably clear of ragwort. Even then a combination of sheep and cattle is required, and, in order to force them to eat the plants at their .vulnerable stage —prior to flowering — the stock have to be held so long on the land that they frequently suffer in condition and production. Except on very small holdings, where the owner can do the work himself, dusting or spraying with sodium chlorate is impracticable 011 the score of labour expense, as is also the cutting, pulling or grubbing which is frequently advocated. Despair Not Warranted Many landholders in this and other ragwort-infested areas, and especially the natives, who have undertaken the development of their own blocks, have consequently become disheartened and fear that no remedy remains but to invoke Government aid to fight this determined enemy, which steps from victory to further conquest. In the writer's opinion this attitude of despair is not warranted. The luxuriant growth of ragwort on this light pumice country is more an indication of a temporary soil condition, during the process of grassing and consolidation, than of a permanent state. As the surface soil becomes consolidated with the trampling of stock and particularly as competitive grasses and clovers form a dense sward, leaving no room for intruding weeds, the problem of ragwort spread will solve itself. There have been countless similar "menaces" in the past—Scotch thistle, wing thistle, Californian thistle, bidibidi and a host of others. All of these, even, including blackberry, gorse, bracken and second growth, have gradually assumed a less important position as "menaces" when the soil Has become consolidated, and simpler methods of stock control, which have kept them in hand, have been learned. So it will inevitably be with ragwort, but ~that time is not yet at hand. Effect TJpon Stock Sheep very quickly acquire a liking for ragwort, as unfortunately do cattle also, and will graze it right down to the roots in preference to good grass. If kept on it too long, however, it has a serious effect in drying up the liver, which at first is stimulated to activity by the plant, and thus promotes quick fattening. Sheep from ragwort-infested land must, therefore, be disposed or, preferably for slaughter, every year, and r stock from "clean" country used to replace them. If they could be closelv held on ragwort without its ultimately killing them, this weed would cease to be a problem. , A logical direction for research to take regarding the control of this weed, therefore, would be toward the discovery of (in antidote which might be giVen to the stock as a drench at regular intervals. There is little doubt that such an antidote exists, and it will probablv be found among the sedative' vegetable extracts. If this were available it would be possible to control'ragwort 011 all grassed country and the weed would immediately lose its terrors for the settler. ... , . Simultaneously it would be advisable, both in the interests of weed control and of greater production from this light volcanic soil, to experiment with grass and clover mixtures which, from their natural peculiarities, are obvipuslv suited to thrive on this class of country, and which could successfully compete with ragwort and similar Weeds. Some Success Achieved Already a considerable amount of success has been achieved with subterranean clover, danthonia pilosa, paspalum, red clover and similar deeprooted and quick-growing, or dense sward-forming, varieties of legumes and er \Vhat would aid considerably in combating' ragwort spread would be a mixture which formed a dense sole all the year round, and contained grasses which would grow equally as fast as. or faster than, ragwort, and so smother it during the spring season when it must have .light and air for growth. The problem of ragwort control is dealt with here because it is felt that the bringing in of further considerable areas of bush and fern-covered hill country in the Bay of Plenty depends on th<> mastering of this toxic weed. Further, until some antidote for ragwort poisoning is discovered, the development, or even maintenance in pasture, of this light pumiceous land is oplv possible in comparatively large areas,' wnere those controlling the work have ample stock at command to thoroughly eat out the country and keep the weed from seeding. The command of money is also essential for stock replacements at the critical season, and to consolidate the soil and establish a dense sward. * An extraordinarily interesting example of what can be done in controlling ragwort and in bringing this land into -/ permanent clean pasture is afforded by the native land development scheme, under the direction of Mr, W. Scott, at Tokerau, .in the neighbourhood of Lake Rotoiti.