No. 1. 



Disease of the Plum. — Fruit Garden. 



35 



A New Disease of the Plum. 



By Dr. T. W. Harris, author of the Entomological 

 Report of the State of Massachusetts. 



Last year an undescribed disease of the 

 plum made its appearance in some gardens 

 of this vicinity, in the latter part of the 

 month of May, and has been observed again 

 during the present season. Soon after the 

 blossom had fallen, the fruit began to swell 

 rapidly, and, in the course of two or three 

 weeks, it had grown to more than ten times 

 the size that it ordinarily attains in the same 

 period. It was soft and compressible, as 

 though it were puffed up with air, being 

 filled with an elastic spongy substance of a 

 whitish colour. In some of these inflated 

 plums no vestige of a kernel remained ; in 

 others, a little, soft, and empty shell was 

 found. After growing from one half to more 

 than three-quarters of an inch in diameter, 

 the fruit dropped, and by the middle of June 

 no more of it was to be seen on the trees. 



The cause of this puffy swelling of the 

 fruit, and abortion of the kernel, is a little 

 thrips ; and several of these minute insects 

 were found, on the 28th of May, on almost 

 all the diseased plums. It is probable that they 

 begin their attacks in the blossom, and that 

 they prevent the impregnation of the ovule 

 or young kernel, by destroying the pollen ; 

 and, by subsequently puncturing the plum, 

 produce an irritation, which is followed by 

 a rapid swelling and diseased condition of 

 the fleshy substance of the fruit. Preter- 

 natural enlargements and distortions of the 

 parts of flowers and of fruits, are known to 

 be occasioned by the attacks of other species 

 of thrips. This may be seen in the blossom 

 of the black whortleberry, (Resinous vac- 

 cinium ;) all parts of which, calyx, corolla, 

 stamens, and ovary, are sometimes enor- 

 mously enlarged, and entirely changed in 

 texture and appearance, in consequence of 

 the punctures of a kind of thrips. 



It is not yet known how far this affection 

 of the plum has extended. In this vicinity 

 it seems to have been confined to certain 

 trees only. Should the insects multiply and 

 spread to 'other trees and other places, they 

 will prove very destructive to the fruit here' 

 after. It remains, therefore, for the prac- 

 tical gardener to watch for their first ap- 

 pearance, and to devise some sure means of 

 killing them, while the trees are in blossom 

 and the fruit is forming. T. W. H. 



Cambridge, June, 1842. 



We invite the attention of our readers to 

 the above. New insects and diseases appear 

 to be upon the increase, and it becomes the 

 intelligent cultivator to watch attentively for 



the causes which produce such dire effects 

 on his fruit trees. We trust we shall be 

 able to offer other communications from Dr. 

 Hams, on the habits of the various insects 

 which annoy trees and plants, and thus be 

 the means of leading to discoveries for ex- 

 tirpating them. — Ed. Magazine of Horti- 

 culture. 



On Setting Out the Fruit Garden. 



One thing is worth bearing in mind by 

 those who purchase fruit trees: the best 

 kinds are generally as hardy as the worst. 

 and the difference in price fades into nothing, 

 when compared with the difference in quali- 

 ty. Nobody is satisfied with mean fruit after 

 having tasted better. For a fruit garden, a 

 western aspect is generally best, because it 

 is the least subject to sudden transitions of 

 temperature. Severe vernal frosts often 

 prove injurious, or otherwise, according to 

 the weather that follows: if the sky be over- 

 cast in the morning and the air continues 

 cold, little or no damage ensues ; but when 

 the sun breaks out warm, the injury is great- 

 est, and the most so, where the trees are ex- 

 posed to its rays. For this reason, a hill or 

 a wood on the east side may prove beneficial. 

 A northern aspect would go far towards in- 

 suring regular crops of the peach, nectarine, 

 and apricot, if protected from the sun and 

 warm winds by a belt of evergreens. On 

 sandy soils especially, the reflected heat is 

 often sufficient in autumn and winter to start 

 the buds, and snow and ice have been suc- 

 cessfully* heaped around the trees to prevent 

 this disaster ; but a northern aspect would, 

 probably, render such labour unnecessary. 

 Dry, firm ground must be chosen, preferring 

 a sandy or gravelly loam, although clay will 

 do well with good culture, but, peaty or 

 spungy soils are apt to be frosty, for the ra- 

 diation of heat from such is much greater 

 than from firmer land. — Thomas. 



Good and Bad Tools. — A writer in the 

 Maine Cultivator, illustrates the importance 

 of having the best implements, by showing 

 that a hand with an excellent axe, and a 

 handle well hung, would cut a pile of wood 

 in 12 days, which would require 16 days la- 

 bour with a poor implement. The difference 

 of cost in the two implements is supposed to 

 be 72 cents, and in this one operation four 

 dollars are saved by the use of a superior 

 tool. This is a fair specimen of the loss or 

 gain by good or bad management, in furnish- 

 ing implements of husbandry. — Far. Jour. 



* The blooming of an apple tree was delayed a fort- 

 night after the rest of the orchard, by piling wood 

 around it. 



