CONFERENCE ON FRUIT-GROWING. 



6 9 



out the cankers before the tree flowers, if thoroughly done, leaves the 

 tree healthy again, and is a practicable way of dealing with this very 

 destructive disease. By adopting this measure, owners of young 

 Derby trees can most certainly keep the" disease under at slight cost ; 

 where old trees have been attacked for several seasons and nothing 

 has been done, then top-grafting has probably to be recommended. 



Among insect diseases, the following instances have been given 

 me by Prof. F. V. Theobald. 



Certain caterpillars can be dealt with in the egg stage. The egg- 

 rings (on the current year's growth) of the Lackey-moth, and the egg- 

 masses of the Vapourer-moth, can be collected by hand. 



" Grease-banding " against the Winter-moth is also an important 

 adjunct to spraying. 



The grubs of the Pear-midge are destroyed if poultry is kept among 

 the trees. 



The Strawberry Ground-beetle can be caught by means of " traps." 



4. CONTROL OF DISEASE BY SPRAYING. 



Lastly, we have the all-important subject of spraying to consider. 

 Without spraying, the fruit-grower cannot hope to grow clean fruit. 

 Let us take the insecticides first. 



It is encouraging to find that numerous discoveries and improve- 

 ments have lately been made in the caterpillar washes. The arsenical 

 washes have been improved and are in a fair way to be standardized. 

 New and efficacious powders used in so-called " dry-spraying " have 

 been discovered, and also pyridine. 



The combined wash of nicotine and arsenic enables us to kill at 

 the same time caterpillars and apple-sucker, and to some extent 

 green-fly. 



Prof. Theobald tells me that he believes that much good can be 

 done by spraying in the autumn against the apple " green-fly," and 

 that a heavy lime-wash used late in the spring is efficacious (through 

 its mechanical action) against apple-sucker and apple-blossom weevil. 



With regard to new or improved fungicides, here again the prospect 

 is equally encouraging. 



The most powerful fungicides known are those containing copper. 

 Bordeaux mixture still holds its own as the most powerful fungicide 

 against such diseases as apple-scab. Personally, I favour the mixture 

 made with an excess of lime. I have seen the best results obtained 

 with this, and I notice that the apple-growers of Nova Scotia are now 

 using a Bordeaux mixture with a very great excess of lime, and claim 

 for this mixture (which has been called " Thompson's Bordeaux 

 Mixture ") that it does not " scorch " the foliage nor " russet " the 

 fruit as other more neutral Bordeaux mixtures do. Then we have the 

 recently-discovered emulsion of copper sulphate and soap, which 

 is safe for use on foliage. This has been used with good effect on 

 potatos, but has yet to be tried on fruit. 



