THE PLUM IN KANSAS. 125 



The knots ought to be removed on account of the attraction they 

 offer to insects, if for no other reason. When the swellings appear 

 on the larger limbs and trunks of the trees, cut them out carefully, 

 extending the cut from two to three inches above and below the 

 knots, and then paint the wounds, first with a strong solution of iron 

 sulphate, and then with some oil paint. From the contagious char- 

 acter of the disease, it can be stamped out only by concerted action, 

 and the extent of the losses which it may occasion when well estab- 

 lished make it a subject for state consideration. Now is the time to 

 take action on this matter. Our fruit interests are too important not 

 to demand the protection which the state can give by stamping out 

 the disease in the sections where it now exists, and by preventing its 

 further introduction through diseased nursery stock. 



REMEDIES FOR BLACK-KNOT. 



From Bulletin No. 81 of the New York Experiment Station. 



Many remedies for the black-knot have been suggested but none 

 has proved to be efficient. The most generally recommended pre- 

 ventive measure is to cut out the knots and destroy them. This 

 work should be done as soon as the knot is observed, and if well car- 

 ried out it is an excellent method of exterminating the disease. 



Since fungicides have come into use, spraying for the black-knot 

 has been recommended. The conclusions drawn by Maynard from 

 the experiments of one season recorded by him were that "the num- 

 ber of warts were very decidedly less where treated with the copper 

 mixture than where untreated, . . . and we believe that the j)lum 

 wart may be held in check by this remedy." 



A thicket of Morello cherries which had been treated during two 

 seasons produced only 165 knots. From another portion of the same 

 thicket which had not been treated there were out 2002 knots on 

 April 25. On November 26 of the same year, this portion yielded 

 8466 new knots, an increase of nearly fifty-eight per cent. Had the 

 sprayed portion remained untreated, it may be supposed that a similar 

 increase would have taken place in this part, making the assured 

 number cut within a fraction of 2000. The reduction of the number 

 of knots from 2000 to 165, considering the present state of our knowl- 

 edge and the conditions under which the experiment was carried on, 

 is encouraging, and point to a final control of the disease. 



Some of the applications which now appear necessary for the con- 

 trol of the black-knot are to be made when other diseases require treat- 

 ment. This necessitates but little extra labor in spraying for the 

 prevention of the knot. - 



