THE ORCHARD.

New Zealand Mail, Issue 1318, 3 June 1897, Page 5

THE ORCHARD.

REMEDIES FOR INSECTS AND FUNGI.

We havo received from Professor E. W. Hilgard, the Director of the Agricultural Experiment. Station, which is connected with the University of California, Bulletin No. 115 dealing with the subjact of “Remedies for Insects and Fungi. The report is drawn up by Mr C. W. Woodworth, and is a most useful one as summarising the facts ascertained during the past few years upon this important branch of economic entomology and mycology. We reproduce the Bulletin for the information of our fruitgrowing readers :

“ It is very important that every ono who has the care of crops, whether of garden, orchard, or field, should have a clear idea of the remedies available for preventing the injuries due to insects and fungi. Not only must one know how to make and apply the remedies, but it is equally essential that he should fully understand when to apply and when not to apply. It is safe to say that, even in California, where this matter has been agitated for so many years, in only a very small fraction of the cases where injury might be prevented is the proper treatment made. On the other hand, it may also be said that when a treatment is made it is often of no effect, and a waste of time and money. Careful observations of the practices in this State in reference to treating insects and fungi makes it appear that fully half of what it now costs to treat our crops is wasted. MISTAKES MADE. The chief mistakes made in applying remedies are the following : “ First—Applications are often made when there is absolutely no need for treatment —when there is nothing to destroy nor to prevent. “Second Applications are often wrongly timed ; either applied before there is any chance to produce good results, or after the injury has all been done. “ Third—Often the wrong kind of an application is chosen for the particular trouble, so that no results can follow. “Fourth—Applications are often made for troubles that are incurable by any known practical method. “Fifth—Expensive methods are employed when cheaper ones will accomplish the results, both as regards the material tried and the labour employed. “ There is no reason why these might not to a great degree be avoided. Mistakes of judgment will always cause loss in this as in any other operation, but there is no reason why these mistakes of ignorance should be allowed to amount to half the cost of such applications. In the following pages we will attempt to present, in a brief compass, the more important points to be considered in the treatment of plants. But it should be distinctly recognized that; local experience and experiment is the only real guide for successful practice. Especially in this stage, when our conditions are so wonderfully diversified, it is impossible to formulate detailed programmes or calendars of operations which will be of general value. “ Any one with ordinary intelligence, however, who is willing to observe and think, has no excuse for falling into the mistakes indicated above. ‘

CLASSES OF PESTS. “ Almost all the serious pests that attack plants are either insects of fungi. These we may classify, according to their way of attacking the plant, into a number of groups, as follows : “1. Root-feeding insects, which attack the roots of plants ; they may devour the root*, suck the sap, or cause swellings to form ; and the same insect may even attack the plant above ground as well as on the roots. “ 2. Boring insects, which live within the plant and mostly attack the stem or trunk, bub may also bore into the larger roots on the one hand and into the interior of leaves and fruit on the other.

“3. Sap sucking insects, which attack the upper parts of the plant, puncturing the leaves and stems to obtain their food. They resemble the forms that suck the sap from the roots, but the latter are a different and much more difficult economic problem. “4. Defoliating insects, which eat up the leaves and other green parts of plants. “5. External fungi, growing over and living upon the exposed parts of the leaves and stems of plants, and only sending feeding suckers into the plant. “ 6. Local Fungi, which enter the plant, bub remain at the point where they found an entrance, and onlyspreac by the spores, which correspond to seed, being carried to other parts of the leaf or plant and there growing into the plant again. “7. Penetrating Fungi, which have the power of passing from one part of a plant to another by boring their way right through the plant. “ Each of these classes of pests must be treated in a different way, and usually the remedy for one would be entirely useless if applied for a pest of another class.

{To be continued)