842 THE AMERICAN FARMER. 



DISEASES AND ENEMIES OF FRUIT. 



IN the animal and vegetable kingdom, every creation seems to have its peculiar diseases 

 and enemies to combat and overcome, or to be overcome thereby; thus we find 

 that every animal and plant has its parasites, which by their depredations may so 

 deplete the natural vigor as to induce disease and sometimes destroy life itself, while these 

 parasites are themselves frequently subject to other parasites that prey upon their vitality in 

 the same manner, and still the latter minute parasites have parasites of their own, and so on; 

 thus in the great economy of Nature there is ever a tendency to maintain a balance of power, 

 when the laws that govern it are not in any way interfered with. A large majority of the 

 diseases of plants are caused by parasites of some kind; in fact, insect enemies and diseases 

 are so closely connected, and their relations to each other are such, that it is often difficult 

 for the farmer and fruit grower to determine to which source to attribute his losses. 



Professor A. S. Fuller says in this connection: &quot;Some species of insects attack only 

 diseased or dead plants; others only the living and healthy. If a plant shows signs of failing, 

 we are inclined to speak of it as being diseased, whether the failure is caused by a lack of 

 some element in the soil, attacks of parasitic fungi, or noxious insects. The loss is the same 

 in the end, whether from one or all of these enemies combined. There are two practical 

 methods of combating insect enemies and diseases of plants ; one is to cultivate so carefully and 

 stimulate the growth of the plants that they may possess the power of resisting attack; the 

 other is to make war directly upon them by artificial means. Of course, the first method 

 is most applicable or practicable against the more minute species, such as plant-lice, rust, 

 smut, and mildew. I do not recommend forcing plants to extremes, in order to enable them 

 to resist tfieir enemies, as this might work an irreparable injury; but the condition to be 

 aimed at should be a healthy, vigorous growth; for anything beyond this is more the sign of 

 weakness than strength. 



The half -starved, over- worked, and uncared-for horse is sure sooner or later to become the 

 prey of various internal and external parasites, which are thrown off, or their attacks success 

 fully resisted by the healthy, vigorous, and well-fed animal; and the same principle holds 

 good all through the animal and vegetable kingdom whether the subject be a man, horse&amp;gt; 

 sturdy oak, or delicate strawberry plant. Not that all diseases are due to loss of vigor through 

 starvation and neglect; but that a large number of them are, is well known. The experience 

 of the grape-grower of France with the Phylloxera is one of the most remarkable instances 

 on record of the success of what may be termed the resistant methods of combating insect 

 enemies. After having searched in vain for many years to find some practical method of 

 destroying this pest, Professor Riley in his remarkable investigations in this country discovered 

 that some of our native American varieties were capable of resisting it, i. e. of growing 

 vigorously notwithstanding the presence of the lice upon their roots. This discovery opened 

 a way out of the difficulty, and the French are successfully availing themselves of it by using 

 our resisting species, as stock for their more susceptible kinds. The Grape Phylloxera is more 

 or less abundant in all of our vineyards, but owing to the rapid and vigorous growth of 

 most of our native varieties, it does comparatively little harm. But we have many kinds 

 of insects that attack our small fruits that cannot be controlled upon this resistant system, 

 and we are compelled to combat them in a more direct and vigorous way.&quot; 



We find that with all vegetable growths, good cultivation and such treatment as tends to 

 promote a vigorous growth and development of the plants, has a tendency to ward off 

 disease and enable the strong vital forces to resist the attacks of such insects as might 

 otherwise cause serious damage. Some classes of insects may be driven away or destroyed 

 by suitable measures, while many of the diseases may be checked, if the proper treatment is 



