Questions And Answers

Press, Volume CI, Issue 29855, 22 June 1962, Page 6

Questions And Answers

THE leaves of my tree Tomato are eaten almost entirely away on an apTarently healthy plant. Apart rom a small fly, smaller than a sand fly, there appears to be no other pest on them. Will this condition right Itself with the colder weather, or Is there any. thing that can be done?— (C.A.G., Le Bons Bay.) It is difficult to say just what is causing tne damage to your plant but I do not think that the fly is responsible. Tree tomatoes are relatively free from pest attack and I can only suggest the presence of some type of caterpillar. Spraying with a D D T preparation should give an effective control Please find enclosed a plant which has appeared tn our Bower garden and also in a neighbouring field of lucerne. Could you please tell me what it is?—(D.C.V., Maruia.) The plant is a species of Drobanche commonly called Bruomrape. It is a complete parasite, living on the roots of a wide range of host plants. The plant is in'eresting in that it has no green colouring matter i and therefore cannot manufacture its own supplies of food ano relies entirely on the host ‘plant It ir not really harmful I am contemplating growi ing rhubarb commercially. Could you offer suggestions oi advise where I could obtain further Information? —U W.V., Christchurch.) I am sorry but personal advice on prospective commercial .ventures lies outside the inten-

tions of this page. I would suggest further contact with the Department of Agriculture. Apart from bulletin 342, which you say you have, there is Bulletin No. 296, "Rhubarb Culture in Canterbury." There is also a bulletin published by the Ministry of Agriculture in Brjtain (No 113, "Rhubarb") which can be obtained from some of the bookshops tn Christchurch. The New Zealand Journal of Agriculture for August. 1960, carries an article on rhubarb.

Would cuttings, rooted Irom standard roses, grow into standard rose trees? If not, how can these be raised?—(Mrs M.P., Papanui.)

Busn roses sold commercially are produced by budding on to a routstock. This is raised from cuttings taken in the winter when the shoots are leafless They should be taken about nine inches tn length and all buds removed except for the top three or four These buds are removed to prevent tuckering taking place after the cutting has rooted. Growth will take place from the buds that have been left, in January or February the named variety of rose is budded on to the stock at or near ground level. This will eventually grow away and prodme a bush rose Stocks for standard roses are produced in the same way, except that the stock is prepared about three teet in length and only the buas from the lower half of the stem are removed. Budding Is done at 30 inches or three feet from the ground Instead of

at ground level. A standard rose is only a bush rose on a long stem. So cuttings from standard will only produce bush types of rose

We have an apricot tree which “bleeds." The sap drips from the trunk and branch, some falls to the ground and some sets hard like glue on the tree, and the bark is split. In season the leaves look quite healthy. Last summer It bore 30 apricots. Can you please tell me what can be dene to

prevent this next spring?— (E.M.S., Spreydon.)

It seems your tree U suffering from a bacterial disease. Pseudomonas syringae, more commonly known as gummosis, blast or dle-back. This common and often serious disease attacks all kinds of stone fruits as well as a wide range of other woody plants. Wood, leaves and fruit are <ll subject to attack. Complete death of the tops is possible whilst young trees up to five or six years can be killed outright and often this can be quite sudden.

Control measures include pruning back to at least nine inches below signs of infection, dipping the secateurs into a 2 per cent, formalin solution or intn methylated spirits between each cut to prevent the spread of (he disease Spraying at monthly intervals with Bordeaux after pruning until bud movement (this Last, as well as one at leaf fall, is particularly Important). The use of the antibiotic, streptomycin, following manufacturer’s recommendations, has given good control.