‘Vegetative Proliferation’

Press, Volume CII, Issue 30313, 13 December 1963, Page 10

‘Vegetative Proliferation’

I have beds of Perfecta roses at Christchurch and Hanmer, where young growths have been produced from the centre of flower buds. It has also been noticed to a lesser extent on other varieties. Reference to books in the library showed the trouble to be vegetative proliferation the cause of which is obscure. One batch of roses has been heavily manured with animal manure, and I wondered if the cause could be nutritional. Is the condition caused by a virus, and if so should the bushes be destroyed? (Mrs) J.S.S. (Christchurch). The trouble, as you have already ascertained, is vegetative proliferation. I can add very little. Unbalanced nutrition has been suggested as a cause, but in your case I do not see how this could be the trouble. Virus has also been suggested and so has mechanical damage to the growing tips at an early stage of development. This trouble may be troublesome one year, and the following year there are no signs of it. I suggest that you wait until next year tu see if the symptoms are again evident, and then if they are it would be better to destroy the bushes and replant. Enclosed are specimens of Christmas lilies which are affected by some disease. Until a few week* ago. a bed of them was growing well and appeared to be healthy with a few of them in hud. Now they seem to be going off in parts of the bed and a similar condition is evident on the same lilies in a neighbour's garden.— H.V.S. (Waikari). The Christmas lilies (Lilium candidum) are infected with botrytis, to which this lily is particularly susceptible. Spraying with bordeaux is advocated which, although it will not produce any improvement on those attacked as in the specimens sent in, at least will prevent the spread of the disease to healthy plants.

My winter sweet has plenty of fruits and seed this year (as enclosed). I v.ould be grateful for advice on whether they should be removed or left on the bush. —A.S. (Sumner). If you want to collect the seed to raise new plants, the fruits should be left on the bush until the seed is ripe. Otherwise they should all be removed. Enclosed are some of my onions, which were sown in the autumn. The seed was dusted with captan and the plants were sprayed with the same fungicide when they first showed disease symptoms. Could you please inform me of the disease, its cause, and how to combat it, for this trouble occurs every year? “Constant Reader” (Sockburn). The disease attacking your onions is white rot. which is capable of living in the soil for five years or more, even when there are no susceptible crops. AU diseased plants should be lifted and burnt and a rotation practiced with as long an interval between the same piece of ground bearing onions as possible; leeks and spring onions can also be attacked, so these should be avoided. When sowing the seed, the drills should be treated with calomel at the rate of one pound to 25 yards of row; if the onions are to be pulled early for salads half this quantity will suffice. W'hen transplanting, seedlings should be dipped into a paste made up of three pounds of calomel and one pint of water. Our rose bushes appear to be a picture of health, but the flowers seem to have flat tops and have an unhealthy appearance as though scorched (specimens enclosed). They have been sprayed several times and even climbers are affected. —E.W. (Geraldine). The damage to the rose blooms is being caused by thrips. Young Kowth should be sprayed with D.T. or lindane before the flower buds have developed, for by the time the buds have developed the thrips are already in between the petals. Two

sprayings at 14-day intervals are recommended. The enclosed specimens. are from a Ballarat apple tree, about 12 years old. It makes very little growth and although it produces a mass of flowers, there is very little fruit: there also seems the possibility of some disease. Could you tell me the method by which lime sulphur is made? Years ago I heard the method given over the radio, but 1 have forgotten the instructions and I cannot find the formula in any garden books. —I.E. (St. Albans). There was considerable difficulty in diagnosing the trouble with the apple as the specimens received were dried up. The lack of fruit may be due to lack of a suitable pollinator. Leaf hopper was present on the specimen sent and this can be controlled by spraying with D.D.T. or malathion. There is also a suggestion of malnutrition and the possibility of dryness at the roots which can be rectified by feeding and watering respectively. Lime sulphur can be made by boiling together hydrate lime and flowers of sulphur. 61b of each to five gallons of water. I have an escallonia hedge that was planted about eight years ago which grew well for about three years, then a branch began to show signs of dying; this spread to adjacent branches. The lower branches are at first affected, the leaves browning and dying, and this condition spread to the top of the hedge. The affected branches often send out new shoots from near ground level but these are sodn affected also. Enclosed is a specimen. Could you identify the trouble and suggest a remedy?—H.J.L. (Leeston). The specimen sent is heavily infested with scale and control can be achieved by spraying with malathion. Due to the heavy infestation repeated sprayings will be necessary until control is achieved; it is suggested that you spray every two to three weeks throughout the summer.