Gardeners’ queries

Press, 1 July 1983, Page 8

Gardeners’ queries

Enclosed is one of my Red Delicious apples. Many of them have this rot in the middle which is not visible from the outside, in fact the apples which have these rotten cores look pretty good before you bite into them. Can you give me the cause, and bow to stop it happening again. They are stored in bags kept in the laundry which is quite cool and only gets a bit of sun. K.H. (Chch). Mouldy core is responsible for the rotting of the central region of this fruit. It is a case of varietal susceptibility to which all apples with an open passage between core and calyx are allergic under certain conditions. Various apple rotting fungi may cause this disease which could be fostered under high humidity in storage. There is no control for fruit on the tree. I recently purchased a hanging pot plant called Hypocyrta tropicana. It is a beautiful plant and has flowered very profusely and is now busy producing new growth. I have not seen any specimens of this plant in the South Island, and would therefore like to know what method should be used to multiply it so that I have a spare one in case this one dies. “Bill” (Chch). Although the species mentioned is not a familiar one,

Hypocyrtas are offered locally from time to time. These plants make attractive, free flowering subjects for the purpose mentioned in your letter. Propagation is not difficult from cuttings taken from nonflowering tips. These should be about 75mm in length with the bottom leaves stripped off them. Root in a suitable friable but moisture retentive medium. Could you give us an answer to our potato problem? They have grown tremendous shaws but the results below ground level have been poor. Over the last few years we have tried several different varieties with no improvement. We grow good vegetables in a fairly shaded back section, which has been well manured — mainly well rotted chicken manure. It has been suggested that we cut the shaws hard back. J.R. (Ashburton). It would seem most probable that the reason for the excessive top growth of these potatoes is the amount of chicken manure applied to the soil. Too rich a soil causes rank growth with minimal tuber development; it can prevent hearting in the likes of •cabbage, or bulbing of onions as further examples of overfeeding. The shady site could also be contributory to drawing the plants up towards the light. Cutting the tops or shaws down will not alter the situation. Crop rotation and/or no

■ additional manuring for the i coming season is suggested. ■ The use of the word shaw in reference to potato tops is uncommon these days, and is apparently a term more commonly used in England — it > would be interesting to know ■ how it came into being and ■ whether it is a corruption of some other word. Gardeners’ queries, which can only be answered in this column, should not be addressed to “The Press,” but sent directly to Mr M. Lusty, 32 Brockworth Place, Christchurch 1. Could you please advise me what I should do to prevent curling of the leaves of outdoor tomatoes? I have grown them in the same place for 10 years, but only in the last two have I had this curling. The last few years I have planted “Vant Cross” tomatoes. L.T. (Hornby). There are several diseases which cause some form of leaf curl of tomatoes. Without further details, or preferably affected samples for examination, it is not possible to answer this query. It is more a case of good fortune to have grown tomatoes for so long, particularly when in the same place all the time, not to have had disease problems before now. Of course, prevailing seasonal conditions and the standard of hygiene maintained would influence matters.