THE MONTHLY BULLETIN. 209 



new tree or treated. Do not try to treat badly infected small trees. It 

 is more expensive than to purchase a healthy tree. A tree after the 

 end of the first year is not so likely ever to contract gall, although it 

 would be well to again inspect the trees at the end of the second 

 season. When a tree is replanted where one has been diseased, care 

 should be taken to use fresh earth in filling in around the tree. 



The treated tree should be marked and examined again, for often the 

 first treatment is not entirely effective and the galls may again begin 

 to appear at the treated margins. If such is the case, the tree should 

 be again treated. The individual judgment of the operator must be 

 used as to whether the small tree had best be replanted or treated. If 

 one begins with the small orchard and is willing to give careful atten- 

 tion to this trouble there should be no difficulty in keeping the crown of 

 the tree free from gall. The root one can not expect to treat. It 

 would be better not to take too much risk in treating badly-galled trees 

 of one year's growth in the orchard, as it is very questionable if such 

 will ever become profitable commercial trees. 



Use Clean Ground. 



If resistant stock can be secured, it should be used in preference to 

 equally as good but susceptible stock. The importance of growing 

 nursery stock in soil free from crown gall infection is becoming more 

 and more recognized by nurserymen. The growers also are demanding 

 such stock and sometimes going to considerable trouble and expense to 

 find nurseries free from gall infection. At present there is no way of 

 easily locating such nurseries except by a personal visit at tree digging 

 time. 



Next in importance to having clean stock is to plant in ground free 

 from natural infection. There is good reason to think that certain of 

 our native trees and shrubs may be sometimes diseased with crown gall. 

 If this is the case, these abnormal growths can often be detected when 

 the land is cleared. Old orchards of stone fruit trees are sometimes 

 removed and again replanted to stone fruits. There is always danger 

 of these old trees being infected. 



It would be safer to wait for two or three years before replanting 

 stone fruit trees in soil recently cleared from diseased trees. Citrus, 

 the olive, or other resistant trees could be planted at once. In cbe 

 meanwhile, the ground could be used for any of the annual crops, but 

 not for alfalfa, as this plant is susceptible to crown gall and woidd 

 probably further infect the soil. 



Germicides. 

 The experiments in using germicides on peach roots have not given 

 satisfactory results. The amount of gall lessened by the treatment 

 was not sufficient to justify its use. There was always injury to the 

 trees Avhen the germicide was of sufficient strength to protect riie tree 

 from infection. In the experiments, Bordeaux paste, as recommended 

 for lemon gummosis, was used, also Bordeaux mixture of the following 

 strengths: 4-6-50, 12-15-50. Concentrated Ortho lime-sulphur and ihe 

 two following strengths of 1-10 and 1-20 were tested. The concentrated 

 solution killed all treated trees, the weaker strengths did not so mark- 

 edly injure the tree as did the Bordeaux solutions, but their bendicial 

 effects were slight. At present there is no chemical solution that can 

 be recommended. 



