226 State Horticultural Society. 



AN INVESTIGATION OF ROOT KNOT. 



So much has been said lately about the "Root Knot," "Root Gall'^ 

 or "Crown Gall" that the nurser}^ trade generally have been led to adopt 

 such means as seems best for its protection toward investigating the- 

 causes of and remedies for this disease. Reputable nurserymen at pres- 

 ent do not claim to grow apple trees without some indications of the 

 disease in their blocks and until some remedy is found to render stocks 

 and grafts immune, the disease will likely continue to prevail where- 

 ever trees are grown to an}' great extent. The disease is much less 

 prevalent than it was years ago in the nurseries. This is in view of the 

 fact that very few, if any, of our commercial establishments are now 

 growing a second crop of apple trees on the same ground. 



The writer has had his attention recently called to a small nursery 

 plant that was made on a piece of land which had been an old seedling 

 orchard, one of the "old pioneers." This orchard had been removed 

 probably lo or 15 years ago. Had really died from old age, apparentl}^ 

 as the trees were probably about 50 years old when the remnant of the 

 orchard was cleaned up. This land was planted in nursery stock and 

 produced the finest crop of Root Knot and Crowai Gall that the winter 

 has ever been called on to witness. I make this explanation that it 

 may be understood that it is no new disease, though the agitation of 

 the subject is of recent date. 



I will state, frankly, that my investigations on this disease have not 

 been satisfactory to me. There is no question but that the disease appears 

 in most cases at the union of the graft and the scion. Any bruise or 

 wound on either" the scion or the root will often produce this disease. 



It seems to be in the soil, and so far as has been ascertained, in all 

 soils, both prairie land and timber land. It seems to be wherever trees 

 are grown. It is found on stock from France also. This disease, in 

 my opinion, however, was here before any nursery concern existed. I 

 do not regard it as a nursery disease. I wish to make this point clear. It 

 appears in the nursery, but any orchard, in my judgment, produced from 

 seedlings, planted iir-the orchard, would not be immune any more than 

 trees transplanted from a nursery would be. 



The disease, in the State of Missouri rarely ever damages to any 

 exlent anything but apple trees. In this we are fortunate. In some 

 states it causes considerable loss to other fruit trees. I understand that 

 on the Pacific Coast it is a serious matter with the peach orchardist. In 



