ERADICATING BLACKBERRY.

Otago Witness, Issue 3612, 5 June 1923, Page 13

ERADICATING BLACKBERRY.

l:i ffoeihoru A ictoiiu tin: bramble or biacivbeiiy is lapuuy uecoa.iig cue 01 our worst peats, atm it is auCcii.j prociaimeu ui.ucr me an.aiie -V< L lor to*- *uue ra**».u. It .3 too we*- liiior.i* to iieetl any tiesei *pUon, Lola on account o* iis iiumeious iruus alio its ag'.essi.e anti persistent lloiii on me places ..nere it uas been allotted io esiaonsn i*sji». t nlorjuuaiely, on account of its fruitfulness, it is outm ailoweu to grow uiidisu.rbetl, or unlit after us fruits nave been Harvested. in tact, it is largely due to llie value some people place on these terries that this plant is now becoming so v. ltlely spread. lhal me truil is permitteil to ripen gives tiie blackberry tremendous posst mil tics of beccimiig one ot our worst pests. The trail is also eagerly sought alter and eueu by many species of birds and animals, with the result that its seeds are being scattered over very wjrie areas, which are, until lecent tunes, comparatively if no* quite tree oi it. Ibe i:iaul.berry is an introduction from Kurope and Asia, and, like most of our introductions, has entered tins country iree from controlling ag'-mies, and. further, lls spread is being facilitated by the assistance given to ii by introduced birds anil animals, as well as by those indigenous lo the country. Many birds eject from the mouth indigestible remains of food; tins usually' consists of the bard parts of insects and seeds of blackberry when the latter is in season. 'lbis seed ejectment is one of Nature’s methods for seed dispersal over wide areas. Animals also assist in the spread of this plant by feeding on the ripe berries, the seeds of which, after passing through the digestive tract, remain viable. "1 he blackberry, in addition to its many had qualities, aftoids id nil cover for rabbits and other vermin, besides often making the banks of rivers and creeks inaccessible of approach. It is also responsible for the death of many sheep. '1 lie' writer lias seen several instances where these animals have lost their lives through becoming hopelessly entangled among the looping brambles, and so dying a miserable death from starvation. Though I lie spread of the blackberry bramble lo clean areas is mostly due to its seed being carried there, in established clumps irs increase is usually due lo (he long arching or trailing brambles becoming rooted al the (ins. and hv these means commencing the formation of a fresh dump, which, unless checked, will ultimately become merged into one tangled mass. Blackbenies have a perennial root-stock without underground creeping, and their piopsgation is usually by the means above mentioned.

(tne of ilie first slops towards blackberry control should be to prevent this plant from fruiting wherever possible. This could be accomplished* either by cutting down the brambles, burning them, or t>y spraying the bushes with chemicals. On cultivable land there need not he such very great difficulty in blackberry eradication. If the clumps or masses are old established, these should lie cut round by means of a horse-drawn mowing machine, or else cut with a slasher. r lhe cut material should then be thrown back on to the mass of uncut brambles and left until fairly dry. Some free-burning material, such as bushes or straw should he added so as to ensure a good burn. If the burn is not a good one by reason of insufficient material, the brambles are merely scorched and roughened, and are then more difficult to cut than they were previous to lxurig fired. If there has been a good clean burn the roots can be completely dug out and burnt, or the land can be ploughed during the warm weather, and often enough to prevent any new shoots arising and tbits feeding any root stocks remaining in the ground. Repeater! cutting of new shoots will starve the root stocks, ultimately killing them; but ettfring, to l>e effective, must be frpqueni and thorough, the chief aim being to prevent leaf formation and thus starving the roots. ih e great difficulty with blackberry control is when this plant is growing on land of a roc-kv or stoney nature or on creek or river frontages, or in situations that make cultivation either impracticable or undesirable on account of the danger of soil erosion during floods. In such places, cutting to prevent fruiting will control the plant without eradicating it, usually two cuttings a year being sufficient 1o stop its further spread. This is unsatisfactory, because the work has to lie repeated year after year, li is cheaper to kiil the roots and have done with them, and for this purpose chemicals could be employed. ff an arsenical preparation is used the branches should first he cut and burnt as already described; otherwise, if the bushes ate sprayed with arsenic without previous cutting and burning, the leaves drop off. leaving a jungle of loose canes that make their removal difficult afterwards. either hv fire or by cutting. ff a clean burn has been obtained, the shoots that will afterwards spring up can be easily destroyed by the arsenical spray every time they make their appearance. There arc at the present time on the market some excellent preparations of arsenic of great solubility that should do away with the necessity for using the home-made preparations, but for those preferring to prepare their own arsenical sprays the following mixture can be recommended as having given good results against blackberries:— Boil together lib white arsenic, 21b v,-ash-in" soda, and two gallons water. When dissolving use a slow fire, only allowing the mixture to simmer: if the solution is boiled rapidly (here is a risk of the material boiling over. The liquid should become quite clear in about 30 minutes; then make it up to 10 gallons. It is not advisable to make a concentrated slock cat dissolved arsenic, as iu all probability ii will crystallise on becoming cold, necessitating it all being boiled over ag.-ui. In sprayng wiih arsenical mixtures one should stand with his hack to the wind, so that the material will he carried away from the operator. As arsenical preparations are exceedingly poisonous, stock should always he removed from land lieing treated with this chemical. \\ hen large masses of blackberries are growing on banks of watercourses (one of the plant’s favourite places) it is not always advisable to use arsenical preparations. In such situations, as many of the canes as cart be reached should he sprayed with crude petroleum during the summer months, and

then the outside masses should tie stashed down amt the lot burnt. Shoots arising later could be again sprayed with this oil, or salt might be liberally applied to the crowns ot plants during hot, dry weather. 1 tie application -of caustic soda has been recommended against blackberries, 11b caustic soda being used to two gallons of water and applied by means of a water-mg-cau. further applications to tie made when new growths appear. A very small mob of goats can be most effectually employed against blackberries. Their smooth liair slews them to poke about among the brambles in search of the leaves without any clanger of becoming entangled, as sheep would under similar conditions, and if all the leaves are kept eaten off the plants will soon be completely killed. Tii© results would be much quicker if the top hamper of brambles were first removed by means of lire and the goats then allowed to deal with the young shoots when these made an appearance.—ll. W. Ravey, F.K.S., Victoria