370 THE YEAR-BOOK OF AGRICULTURE. 



propensity to use a jackknife. My trees are mostly grafted on to suckers of the native or 

 wild plum, near or at the surface of the ground. The scions take well in such stocks, and 

 grow strong, frequently from four to seven feet in a season. In the spring of the first year, 

 I cut back to two or two and a-half feet, and each spring following from one-third to seven- 

 eighths of the last year's growth. This causes them to grow stocky, with low, bushy heads, 

 and to set thickly with fruit-spurs. I have trees in different varieties of soil : some in cul- 

 tivated, some in grass land. All do well. I manure with what is most convenient, without 

 regard to kind or quantity. 



The great enemy of the plum-tree is the black knot. Now comes the grand question 

 Black knot, what is it ? Is it a disease or the work of an insect ? I will endeavor to 

 answer these questions according to my observations. I consider it to be the work of an 

 insect, with which I have no personal acquaintance except in the maggot state. 



From frequent observation, combined with practice, I find that June is the time to look 

 for the enemy. There are no black knots then of this year's growth, but simply swellings 

 upon the branches. Now use your jackknife, and you are sure of your foe. When these 

 swellings first commence, so as easily to be found, the insect is the exact color of the excres- 

 cence, and so small as usually to escape detection. Nevertheless he is there. From the 

 middle of June to the 1st of July they are easily found, generally two in a knot, varying 

 from one-twentieth to three-eighths of an inch in length the largest, in the mean time, are 

 leaving their cells. I have found them near by, sheltered by the rough bark, covering 

 themselves with a thin silk-like web. To all who wish to raise plums, I would say, here lies 

 the secret. Cut green knots instead of black ones. By following this practice, I have 

 succeeded in raising very fine trees not a black knot is ever seen on them. A swelling is 

 occasionally found, but it is taken in time to secure the maggot. By this means the insects 

 are reduced to that degree that my trees never suffer thereby. I have trees from four to 

 six years from the graft, from eight to ten feet high, with large, spreading heads, bearing 

 the first season from one to more than two bushels per tree of most splendid fruit. 



In regard to the curculio, the following is my experience : Among all the remedies here- 

 tofore published, only one has secured the design intended. I do not say that most or any 

 of them are "humbugs," but that the curculio is a "hum-bug" in spite of them. I have 

 tested, and I think fairly, lime, ashes, plaster, sulphur, cotton all without avail. I do not 

 doubt the sincerity of those giving the above remedies, but think they must have been 

 deceived ; that the curculio was not there at all, or in numbers so small as not seriously to 

 effect damage. It requires but little observation to convince any one that insects of all 

 descriptions migrate from place to place, overrunning one vicinity, and vacating another in 

 close proximity, or even one or more trees of a garden, while others are not infested at 

 all. I know not what any one has, or what else may be, discovered, but so far with me 

 jarring is the only remedy that has had the desired effect. Either the curculio here is not 

 so sensitive or not so well behaved as in other places, for he seems determined to yield to 

 nothing but death. Therefore I would advise those who wish to be sure of their plums, to 

 commence as soon as they are fairly set, jarring on to sheets, and killing, once a day (at 

 noon) for two weeks. This has with me secured a bountiful crop. 



At a recent meeting of the New York Farmers' Club, Prof. Mapes stated that he practised 

 this year jarring off the plums in the early part of the season that were bitten, all of which 

 were burned ; and thus he so far destroyed the curculio that he has had large quantities of 

 the finest plums. 



Dr. Underbill stated, that he planted his plum-trees in such a manner that they hang 

 over water, and was not troubled with curculio in the slightest degree. " Upon 150 trees 

 thus planted, I have never found a single curculio. The trees are set in the bank of an 

 artificial pond, at an angle of 45." 



Dr. Underbill further stated, that his plan to get rid of the trouble of caterpillars "is to cut 

 down every wild cherry-tree about my place. Some preserve these trees for the worms to 

 breed upon. It is an error. They are the great breeding places of all caterpillars that are 

 destructive to fruit. My opinion is, that every wild cherry-tree should be exterminated." 



Mr. Henry Croft, of the Toronto Horticultural Society, recommends the use of sulphu- 



