438 Reporr or tHE HorvricuLTuRIst OF THE 
Occasionally, they occur also on the trunk above ground. In all 
cases the knots are detrimental to the trees and when they occur 
at the crown the tree is worthless. 
The disease is common in some of the nurseries in the State. 
The cause of it is wholly unknown. There are indications that 
it is infectious but this has not been proven. 
Similar knots occur on the roots of the raspberry, blackberry, 
pear, apple, plum, apricot, grape, and a few other woody plants. 
Among fruit growers it is the popular opinion that the disease is 
the same on all of these different plants, and that any one of 
them may communicate the disease to the others. However, this 
has not yet been demonstrated by carefully conducted experi- 
ments. 
Treatment.— No remedy is known. Affected trees should 
never be planted. It is not even safe to plant trees from which 
the knots have been removed. Avoid planting fruit trees in soil 
known to be badly infested by the disease. 
FRUIT ROT OR RIPE ROT. 
(Monelia fructigena P.) 
The ripe rot of the peach is caused by the same fungus as that 
which produces the ripe rot of cherry and plum. It is discussed 
on age 420. 
Treatment.— Chester”’ who has given special attention to this 
subject advocates spraying with Bordeaux mixture just before 
the blossoms open and again after the fruit sets. Spray with 
copper acetate (finely powdered, 8 ounces to the barrel), when the 
fruit is ripening. Copper acetate does not discolor the fruit as 
Bordeaux mixture does. Observe the caution given above con- 
cerning the liability of injuring peach foliage by spraying. 
GUMMING. 
The formation of gum by the apricot, cherry, peach or plum 
may follow any injury by cuts or bruises or by the attacks of 
27 Chester, F. D. Ninth Ann. Rept. Del. Agr. Exp. Sta., 1897: 28. 
