Gardeners queries

Press, 11 July 1980, Page 7

Gardeners queries

I have a Jack Humm crab apple which bears apples prolifically but unfortunately they are very prone to black spot. I have sprayed them at regular intervals with captan but this has not made any significant difference. Is there any other spray which you can recommend that would clear the trouble up?—"Floral Art" (Chch). In the last year or two black spot has become one of the most troublesome diseases of apple trees. Even with spraying, timeliness of application, as well as suitable fungicides, is necessary once this fungus disease has become established. Carry over could cause continued problems in the coming season, especially under conditions favouring its development. There are

various lines of attack and the following is one suggestion for use in the home garden: A Bordeaux spray at green tip should be followed by an application of dodine, if possible, and thereafter maneb or captan at regular intervals at least until early in the, new year. Benlate should’ be applied as thoroughly as possible well before leaf fall. It is very important to get that green tip spray on at the right time and to repeat any spray should wet weather occur shortlj’ after application. I would appreciate your advice regarding our present problem with chick weed in our bulb bed as it does not get dug over very often. The chick weed has taken over. How can we get rid of it without any damage to the lily

bulbs? The growth is very lush.—J.R. (Chch). Mature chick weed is relatively easy to remove as it can almost be rolled up on the ground. Paraquat, diquat, a combination of the two, or glyphosate, if applied on a warm sunny day and providing none of the bulbs are showing above ground, will quickly eliminate existing weed. It should be noted that none of the herbicides, mentioned are residual, which means that they will not stop a fresh infestation of chick weed from developing — a factor which must be contended with at this time of the year. Readers desirous of having queries answered in this column must include their name and address, whether a nom-de-plume is used or not.