January, 191 i 



THE CANADIAN HORTICULTURIST 



I 



harrows, cultivators, and other tools us- 

 ed in the orchard, after coming in contact 

 with a diseased tree, are potent carriers 

 of the disease. We have seen numerous 

 cases of blight that could clearly be trac- 

 ed to this source of infection ; and we 

 proved in a number of experiments how 

 easy it is for the disease to spread in this 

 way. 



After using a saw on the diseased part 

 of a tree and then on the healthy tree, 

 niching the bark or cutting off branches, 

 we found that in seventy-five per cent, 

 of the experiments the healthy tree con- 

 tracted the disease at the point cut. 

 Scraping healthy trees with diseased 

 trees when removing the latter from the 

 orchard is also a common method of in- 

 oculating healthy trees. 



ERADICATION AND PREVENTION 



When once the disease enters a tree, 

 whether it be in the fruit, twig, branch, 

 or trunk, there is no remedy for the affec- 

 ted part. The only measure to be adopt- 

 ed is to cut out and burn it right away. 

 To cut off an affected twig will save the 

 branch on which it grows, and to cut off 

 a diseased large branch will save the 

 tree. 



In cutting dead or diseased tissue from 

 a tree, care must be taken to cut from 

 six inches to a foot below the blighted 

 area, as the germs always extend fur- 

 ther than the visibly affected part. 

 Whenever the pruning tool comes in 

 contact with the disease in pruning oper- 

 ations, it should be disinfected by being 

 wiped with a disinfectant, as corrosive 

 sublimate, 1-1,000 parts or 10 per cent, 

 formalin. These may be carried in a 

 glass bottle. If a wire is run through 

 the cork so as to project into the bottle, 

 and a piece of rag tied around the end of 

 the wire, this may be used as a conven- 

 ient swab for applying the disinfectant. 



The best time to cut out blight is the 

 first time it is seen, as every case of ac- 

 tive blight is a potent source of infection 

 for innumerable other cases. However, 

 it is not always practicable to locate 

 every case of blight as it occurs. The 

 best time for systematic action in an or- 

 chard is in late fall or early winter. At 

 this time the diseased parts are more 

 readily noticed than in late winter or 

 early spring ; and if precautions are tak- 

 en to burn the material out, this will en- 

 sure the destruction of the beetles, aph- 

 ids, and other insects harboring on and 

 in it. 



If an orchard be cleared of the blight 

 during the winter there will be no germs 

 there for insects to get contaminated 

 with in the following spring. Hence as 

 the bees and wasps go from flower to 

 flower they will not infect the blossoms. 

 The blossoms not being inoculated, there 

 will be no early twig blight ; so that when 

 the aphids come later in the season, there 

 will be no source of infection for them. 



If, however, there should be affected 

 trees in the neighborhood of the orchard, 

 .which is usually the case, then the only 

 way to keep the disease out of the or- 

 chard is to control the insects. 



The aphids may be kept in check by 

 spraying the trees when the buds are just 

 beginning to swell with home-boiled 

 lime-sulphur, preferably of the strength 

 of twenty-five pounds lime, twenty 

 pounds sulphur, to forty gallons of water. 

 This is to kill the eggs which may be 

 seen on the twigs and small branches of 

 the tree. To destroy the aphids in sum- 

 mer, give them a thorough drenching 

 with kerosene emulsion. In the fall ob- 

 serve if any aphids are present on the 

 water sprouts, where they will be found, 

 if there are any on the trees at this time 

 of year. If present, cut off the water 

 sprouts and destroy them. 



Several bad outbreaks of the fruit- 

 bark-boring beetle in peach and cherry 

 orchards have been traced to wood piles 



made from diseased and dead wood taken 

 from the orchard. It is in such wood 

 that beetles winter. In the spring they 

 issue from it in large numbers and make 

 their way usually to the orchard once 

 more. This shows the necessity for 

 burning before spring the dead and dis- 

 eased wood taken from the orchard. 



Several orchards, that two years ago 

 were badly infected with blight, are now 

 after being carefully treated as above 

 outlined, free from the disease. It now 

 will be a comparatively easy matter for 

 the owners to keep their orchards free 

 from the disease by making an occasion- 

 al inspection during the growing season 

 and cutting out the fresh inoculations 

 that are brought by insects from neigh- 

 boring property. 



W feel certain that if concerted action 

 such as indicated be taken by all fruit 

 growers in any district, the disease may 

 be wiped out of that district and be pre- 

 vented from entering it again. 



Cover Crops in the Orchard' 



Prol. W. S. Blair, Macdonald College, Que. 



The following experiment in orchard 

 management proves that the soil moisture 

 conditions can be controlled more effect- 

 ively by the date of seeding than by any 

 particular cover crop. Crimson clover 

 was sown on June 15th and on July 15th. 

 The soil samples taken on the first of 

 September showed six and one-tenth per 

 cent, of moisture for the early seeding as 

 against twelve and three-hundredths for 

 the later seed plot. These results are 

 what one would expect, and the date of 

 seeding advisable for different sections 

 and different types of soil can be deter- 

 mined only by conducting similar experi- 

 ments in your section. After conducting 



various tests 



we have set- 

 tled on the 



last of June 



or early in 



July as the 



most suitable 



in our section 



for ripening 



young trees. 

 If trees are 



carr y i n g a 



good crop of 



fruit there is 



little 1 i keli- 



hood of the 



ing of the cover crops. For this rea- 

 son, I advise later seeding in the beaiing 

 orchard, say the middle of July. It is 

 well also to keep in mind that cover crops 

 have a much more rapid growth in a 

 young bearing orchard where there is lit- 

 tle shade than in an old one heavily 

 shaded, and the transpiration in protected 

 areas is not nearly so great as in the un- 

 protected. 



THE QUESTION OF MOISTURE 



While a cover crop may dry out the 

 soil early in the season that does not im- 

 ply that the soil will continue dry until 

 late fall and injuries from dry winter 

 freezing result. Our experiments go to 



wood not rip- 

 ening well, 

 and it would 

 be unwise to 

 dry out the 

 soil too much 

 by early seed- 



"This article is 

 continued from 

 the December 

 number. 



A Honte of Applet Shewn at the Oalario HorticuUural Exhibitioo 



One of the most striking features of tlie recent Ontario Horticultural Exhibi- 

 tion in Toronto, was the house of applea shown by the fruit growers of Northum- 

 berland and Durham Counties. Their exhibit is here illustrated. 



