62 THE BLACK-KNOT. 



troyed. The sheets iiiay be expanded upon sqnare or rounded 

 frames hinged together so as to be folded up, or they may be 

 mounted upon a wheelbarrow for convenienee of moving about, 

 as shown in the accompanying Figure No. 47. The jar nuist be 

 very sudden to bring down the pi'ey, and is best doue with a 

 wooden mallet covered A^th a thick cloth pad or a long, heavy 

 stick padded at the end. This work must be kept up for three 

 weeks from the time the fruit is the size of a pea; it is effectual 

 and not very expensive. 



Planting the trees in poultry-yards is also a sure way to secure 

 the fruit from the attacks of the curculio. The fowls probably 

 catch the beetles as they come out of the ground, and also the 

 larvse as they escape from the fruit. If planted in large quan- 

 tities, probably the addition of swine to destroy the falling fruit 

 containing the larvse would be ad^•^sable. 



The Peach-Borer, Fig. -48, Page 56, is often injurious to the 

 roots of the Phmi, and the same remedy should be applied as 

 for the peach-tree. 



The Rose-Bug, described under those insects injurious to the 

 grape, Page 80, is often very destructive to the foliage, especially 

 to young trees. The application of pyrethrum powder, espe- 

 cially the kind kno^^nl as Buhach, if applied in the evening, will 

 paralyze them so that the bugs will fall upon the curculio frame, 

 when they may be very easily destroyed. 



Diseases. — TAe 5/aoi- Tr«r/ or Black-Knot, is the most des- 

 tructive disease that the Plum is subject to. It is a fungus, 

 {Sph(eria 7norbosa,) the spores or seeds of which germinate upon 

 the tree, genei-ally upon the branches, in the spring. The roots 

 of this fungus plant, known as the mycelium, penetrate the tissue 

 of the Plum tree; the tree puts forth an increased growth to 

 overcome or overgrow the injury of the fungus itself, thus pro- 

 ducing the black wart, so often seen upon old Plum trees and the 

 common sour cherry. The spores of this fungus do not ripen 

 until winter, when they are scattered, and are ready to germin- 

 ate again in the spring. 



The Remedy. — The simplest remedy is to cut oflf the affected 

 limbs a few inches above the part di.seased and burn them. 

 Use care to disinfect the knife or saw, by dipping in kerosene 

 or dilute carbolic acid after cutting each limb so as to preclude 

 all possibility of infecting the next limb cut. A thorough 

 spraying of the trees with Bordeaux mixtiire several times 

 during the season, beginning before the buds break, has been 

 found very effective. Paint wounds with Bordeaux. 



KoTTiXG OF THE Frl'IT. — This occurs, as in the peach, in 

 moist, warm weather, and when the trees are overloaded. If the 

 directions given for the production of choice fruit and the pro- 

 duction of healthy, vigorous trees be followed, the grower will 

 not be much troubled by his fruit rotting upon the trees. 



