TO CORRESPONDENTS.

Auckland Star, Volume LXIV, Issue 88, 15 April 1933, Page 6 (Supplement)

TO CORRESPONDENTS.

P.M.P. (Remuera) writes : Some Gamekeeper potatoes I am saving for seed have been attacked toy a maggot, which has riddled the tubers, nearly every seed being attacked. The maggot is about half an inch long, cream coloured, with a brownish head. The potatoes were dug in fine weather and allowed to remain on the ground till quite green. It appears to me that this was when the tubers were attacked. (1) Is the seed of any use? (2) Is it advisable to use it for next season? (3) What Is the best method of • dealing with the pest?— Due to the grub of the potato moth. It attacks tubers exposed to the air. A covering of soil protects tubers from its attacks. (1) The grub spoils the tubers, as they eat out the "eyes." (2) It Is not advisable to plant affected seed. It should be boiled and fed to fowls or pigs. (3) Keeping the tubers covered with soil Is the best means of prevention. This includes thoroughly moulding up the plants when growing and ensuring that the soil is packed well up around the haulms or stems, so that the.moth has no chance to reach the tubers and lay its eggs. When lifting do not leave the tubers e-vposed. Covering or keeping In hags is of no avail; the only safe method is to cover with at least four inches of soil. In dealing with tubers for seed, box them as soon as possible, and dust them with a mixture of naphthalene one part, arsenate of lead powder one part', and flowers of sulphur ten parts. This acts as a deterrent. WILLOW (Hemuera) asks: I have a willow tree growing near a sewer drain, and tho roots are growing Into the drain, and causing blockages. Can you tell me how I can kill the tree?— Cut down the tree, bore with an inch auger a hole down the centre of the stump, put in an ounce or so of sodium chlorate, add a little water, and then plug it with a wooden plug. Saltpetre could be used instead of sodium chlorate. Any shoots that appear should ba cut off.

H. (Hamilton) wishes to know a good selection of showy rock garden plants.—Alyssum saxatlle, Alyssum saxatile citrlna. Anemone fuigens, Aqullegia alplna, Aquilegia glandulo?ii, Arenarla Baiearfca, Aubretias (various), Campanula carpatica, Campanula carpatica alba, Campanula (various), Dianthus alponus, Dianthus caesius, Dianthus deltolues, Dianthus (other varieties), Gentiana acaulls, Geranium Traveraii, Helianthemums (various), Heucliera (various), Iberia Gibraltarica, Iberis Scmpervirens, Llnnm alplnum, Lithospermum prostratnm, .Myosotis alpestris, Myosotis dissitiflora, Narcissus minimus, Narcissus bulbocodium, Narcissus (specius), Omphalodes verna, Papaver alplna, Phlox subulata (varieties), Primulas (various), Saponaria ocymoldcs, Saxifraga aizoon, Sllene acaulls, Solidago alpestris, Solidago prostrata, Spiroa arcunta, Spirca Spiroa decumbens, Tanacetum argentoum, Teucrinum chamaedrvs, Thalictrum minus .adiantifollum, Thymus (various), Trollis ariatlcus, Tunica Saxifraga, Verbena vernosa, Vcronica (Various), Viola (various), Wahlenbergia. HILLCREST (Papatoetoe) asks : Would you tell me the reason for apple trees bearing a second crop of fruit, and If it does any harm? (2) When is the correct time to plant rose cuttings?—(l) Due to the exceptionally fine weather. It does little harm, and, in any case, Is beyond control. (2) Insert rose cuttings now. LEMON ANXIOUS (Sandringham) asks: What Is the matter with my lemon tree? When the- fruit comes it turns purple, then black, and finally falls off. Half of each leaf turns brown and dry.—Thero are scale Insects on the branches, and the cause of the leaves going off is a fungoid disease. Spray with lime-sulphur (1 —I2v>). Give another spraying a month later, and also another in early summer, after the fruit has set.

Further answers held over until next week.