364r DISEASES AND INSECTS. 



Northern Kew York, in Maine, Yermont, and Lower 

 Canada, the finest large English varieties are brought to 

 greater perfection than in warmer districts, and with good 

 culture almost come up to the English standard. In a 

 cold, damp-bottomed soil at Toronto, almost on a level 

 with Lake Ontario, fine crops are produced with compara- 

 tively little difficulty from mildew or rust. This would 

 indicate as a remedy, a cool soil and situation, and mulch- 

 ing the roots to keep them cool. The plants should be 

 renewed every three or four years, and they should be 

 kept vigorous by liberal manuring and good culture. 



6. The Plum Wart or Black Knot. The cause of this 

 disease is quite uncertain, but the probability is that it 

 originates in a similar way to the gum, from an imperfect 

 circulation of the sap, induced by violent changes of tem- 

 perature.* Cutting out the diseased branch clean to the 

 sound wood, the moment the knots begin to appear, is an 

 effectual remedy, and they should all be burnt up. We 

 have saved trees six inches in diameter, that were affected 

 on the trunk so seriously, that one third of its thickness 

 had to be removed to get below the disease. After it was 

 cut out, we applied a plaster of grafting composition, 

 covered it with a cloth, and in two years it was all healed 

 over and sound. 



Plum trees are so neglected in the country, that multi- 

 tudes of them are now standing literally loaded with these 

 warts not even an inch of any branch free from them 

 the most disgusting objects in the way of fruit trees that 

 can possibly be imagined. 



6. The, Curl of the leaf in the Peach. This disease 

 causes the leaves to assume a reddish color, to become 



* We have observed that cold weather, about the blossoming period, in- 

 duces the gum in plum trees as well as in the peach, and when it continues 

 long, as in 1849-50 in Western New York, there is an unusual development 

 of it. 



