422 BOAED OF AGEICULTUEE. 



quarts or even more arsenate of lead in twenty to twenty-five gallons solu- 

 tion. Arsenate of lead does not dry, but forms a pasty precipitate almost 

 pure white. It remains well in suspension and does not need the constant 

 agitation required in Bordeaux or water where Paris green is used. Usually 

 arsenate of soda costs about 8 cents per pound and acetate of lead about 

 14 cents. In other words, when these chemicals are combined, arsenate of 

 lead costs, when homemade, about 14 cents per pound.— Ed.] 



ROOT ROT OP FRUIT TREES. 



The Oklahoma Experiment Station has published a bulletin summariz- 

 ing an investigation of a serious root-rot disease which is destroying many 

 fruit trees in the orchards of the State. -The disease has been noticed 

 in many localities and seems to be confined to lands that have been 

 cleared of timber before planting to trees. 



The symptoms of this disease are so characteristic that no one should 

 experience any great difficulty in correctly diagnosing any suspected cases. 

 Perhaps the most characteristic effect of the attacks of this fungus is the 

 great exudation of gum about and from the crown of the diseased trees. 

 This flow of gum occurs in maple, peach and cherry trees and is reported 

 for the apricot tree. It frequently happens that the amount of this gum 

 to exude is so great that it unites with the soil about the base of the tree 

 to such an extent as to form a mass of cemented soil about the tree. In 

 many cases this mass of gum-cemented soil will become hardened to form 

 a sort of cast about the crown and larger roots of the tree. 



"The yellow coloration of the leaves is usually one of the prominent 

 symptoms of the disease. In many cases, however, the leaves wilt rapidly 

 during the growing season instead of becoming yellow. This rapid wilt- 

 ing of leaves is the first external evidence afforded that the root system 

 of the tree and consequently its absorptive ability have been greatly 

 reduced. 



"The groups of mushrooms found about the base of the trees will afford 

 the most positive evidence of the presence of this disease. But unfor- 

 tunately this evidence comes too late for the application of any remedial 

 agent; for the mushrooms seldom appear about the crown of the tree until 

 the disease has so far progressed that no preventive or remedial measures 

 can be applied. 



"The fungus of this type is well provided with means to insure its 

 rapid disti-ibution throughout large orchards. The spores, that are pro- 

 duced in such large numbers, are easily scattered about and each one may, 

 under proper conditions, give rise to a mycelium and the typical sporo- 

 phores. Perhaps the beetles that are often seen eating the old pilei are 

 of some value in distributing the spores, but this point needs some further 

 investigation. 



