Part 79 (2/2)
Can you give directions for the prevention of injury by the red spider to almond and other trees in the Sacramento volley?
The red spider on almond and prune trees is usually controlled by the thorough application of dry sulphur to the foliage. On almonds the first sulphuring should be done as soon as the leaves appear in March. A second application is advised from the 1st to the 10th of May. A third application should be made from the 1st to the 10th of June. Prune trees should be treated as soon as the spider appears. In the Sacramento valley this usually occurs about the first week of July. Full-grown trees require about a pound of sulphur which should be thoroughly distributed throughout the foliage. The old method of throwing a handful of sulphur in the branches of the tree or on the ground under the tree is valueless. The use of a blower is economical in large orchards, but a can with perforated bottom is frequently used on young trees or small orchards with good results. In normal seasons the spider is easily, controlled by dry sulphuring. When the pest does not yield to this treatment, a spray is recommended.
Liquid Spray for Red Spider.
Is there any liquid spray I can use in my spraying that will kill the red spider without injuring the foliage of the almond?
A liquid spray for red spider is made by taking sulphur 30 pounds; lime (reduced to milk form by water), 15 pounds; water, 200 gallons; or use commercial lime-sulphur, 4 or 5 gallons to 200 gallons of water. These sprays can be applied without injuring the foliage. They are more expensive in labor cost than dry sulphuring, but are more effective.
Apple-Leaf Aphis.
I am sending herewith a small piece from one of my young apple trees. If you can, will you kindly tell me what the insects are an it, and what I had better do for them?
The apple twig which you send is infested with the eggs of the leaf aphis or leaf louse. These eggs are very difficult to kill. A good thorough spraying with lime-sulphur might, however, get rid of many of them and would be good for the trees otherwise - diluting according to condition of tree growth. The chief campaign against the leaf aphis, however, must be made early in the growing season, just as these pests are beginning to hatch out and to acc.u.mulate under the leaves of the new growth. They should then be attacked with properly made kerosene emulsion or tobacco extract with a nozzle suited to land the spray on the under side of the leaves. Unless these pests are attacked early in the season and repeated if necessary, your apples on bearing trees will be ruined so far as they attack them, being small, misshaped and worthless. On young trees the destruction of the foliage is fatal to good growth.
Woolly Aphis.
Will you kindly inform me what you consider the best treatment for apple trees affected by woolly aphis?
The best way to kill the woolly aphis on the roots is to remove the earth from around the tree to a distance of one or two feet, according to the size of the tree, digging away a few inches of the surface soil, Then soak the soil around the tree with kerosene emulsion, properly made, of 15 per cent strength, and replace the earth. Be sure you get a good emulsion, for free oil is dangerous. For the insects above ground on the twigs, a good spraying while the tree is out of leaf will kill many, but some will survive for summer spraying, and for this a tobacco spray may be most convenient.
Blister Mite on Walnuts.
I am sending you some walnut leaves with some swellings an them. They are very plentiful on some trees here. Is the trouble serious and will it spread?
This is merely Erinose, or Blister Mite, which is a very common trouble on walnuts, but does not do enough damage to call for methods of control. These swellings are caused by numerous, very small insects which live within the blisters on the under side of the leaf amongst a felt-like, heavy growth which develops there. While this effect is very common, it produces no appreciable injury and needs no treatment for its control.
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