CITRUS TREES.

Taranaki Daily News, 25 July 1921, Page 7

CITRUS TREES.

DISEASES AND CULTURE. VALUABLE HINTS AND ADVICE. I Writes Mr. W. W. Smith, the Well- ■ known botanist, etc., to the editor ■ — 1 Sir, —Five months ago you were good I enough to publish some note.-’, of mine jon the diseases of lemon trees. May 1 ' again request you to permit me to deal ! further with this important subject per ( medium of the News? I would earnestly j impress upon your numerous country readers who have the opportunity of j growing lemon trees that, under good | culture treatment, the climate and soils : of Taranaki are well adapted to the cul- | ture of most varieties of citrus fruits. 1 The citron, lemon, orange and other allied fruits are all more or less liable to be attacked by diseases in all countries Where they are cultivated. As explained in my former notes, the lemon trees I hitherto cultivated in Taranaki have oe- ‘ casionally been much injured by the larvae of the so-called puriri moth boring their stems. The eggs are generally deposited by the moth in hollows in the bark on the lower parts of the stems. 1 This habit of the moth could be prevenc[ed by training the young trees with a; .clear skin of 2ft and binding the latter ' around with any rough sacking of old | clothing. The young larvae, on entering the stems, bore their tunnels at an upward angle until they reach the centre of the stem, when they begin to burrow downwards. The tunnel soon becomes moistened with the aap of the tree, which process renders the hard internal wood more easily eaten and assimilated by the larvae. This insect, so far, has proved to be the chief enemy of fruitculture in Taranaki. The citron scale (mytilopsis citricola), a native of North America, was accidentally introduced with lemon or citron plants many years ago, and has been a serious nuisance on the foliage of citrus trees. A solution of fresh horse manure soaked for a day in any old vessel with a little diluted washing soda added will generally cleat the young trees of scale-insects after two good sprayings with the solution. In some districts, during dry seasons, the introduced Indian black cricket has proved extremely destructive in consuming the bark and foliage of citrus trees. The insect occurs in Taranaki, where its feeble, shrill call may be heard in the grass during the night and on dull days from September onward till May. There need be no alarm at this insect proving destructive in Taranaki. The climate is too humid for the species to increase to the extent of becoming destructive. The disease known in America as “mot-* tied leaf” has for years baffled the officers of the fruit disease investigations, 1 United States Department of Agricul- ' ture. It as known as chlorosis, or yel- ; lowing of citrus trees, and is reported to be caused by an irregular supply of food and moisture, and was correlated in a large number of cases with a low humus content. The disease is unknown at 1 present in New Zealand. The culture of citrons, lemons and oranges under liberal and practical treatment is absolutely assured in Taranaki. The largest and finest grown lemons probably £ver produced in New Zealand are grown annually by Mr. John'Wheeler, of Vogeltown. Four years ago I induced a farmer friend to cut back some lemon and orange trees in his orchard, and try the experiment of liberal and careful treatment for a few years. The trees were afterwards fully" cleared around and heavily mulched with fresh soil and fresh horse manure. Last season they bore some excellent and clean fruit, this season are bearing a much heavidj" crop. The samples accompanying these notes are from the trees experimented with.

When planting young citrus trees of any variety it is of first importance to dig good-sized holes and fill them with good fresh soil to enable the plants to start growth vigorously. Keeping the surface clean around the trees and adding fresh mulching of soil and manure annually keeps the roots near the surface where the sun’s warmth is essential to developing and flavoring the fruit. The experiments in cultivating the eight or nine varieties of commercial oranges, or the five or six varieties of lemons and citrons, have been undertaken in Taranaki.’ The varieties cabuyao, sweet orange, and the calamondia, flourish as healthy trees l , and fruit well in Taranaki under good soil conditions and treatment.

I send you the foregoing notea with an earnest desire to induce farmers to plant and grow these wholesome fruits. Needless to say they flourish better in sheltered situations having a sunny aspect.