SCIENCE OF FRUIT-SPRAYING 337 



stock solution by using a pound each of lime and blue- 

 stone to one gallon of water, bottle it, and use it with 

 the extra water which is necessary as required. The 

 cost will be a little over two shillings per 100 gallons, as 

 the Bordeaux can be bought at 255. to 355. per cwt. 

 It should be purchased with a guarantee of 98 per cent. 

 This may be applied in a fine spray when the trees are 

 in leaf, but it would not cure an advanced attack, and 

 must be used at the first sign of injury. Indeed, growers 

 who find from experience that they may expect " blister " 

 try to prevent it by spraying with " winter Bordeaux," 

 that is, bluestone used without lime at the rate of one 

 pound per 25 gallons of water. 



Growers of Peaches and Nectarines under glass are 

 not likely to have an attack of " blister " on their trees 

 unless they allow the ventilators or doors to remain open 

 when a cold wind is blowing and can drive straight 

 on to the trees ; but outdoor cultivators are always 

 liable to suffer, and must be on their guard. The 

 fungus forms large brownish " warts " on the foliage, 

 which speedily falls. It is the most deadly when the 

 young leaves have been checked by a cold wind, in fact, 

 it is capable of killing off a whole wailful of trees in a 

 day or two. 



Pears suffer from several caterpillars and fungi the 

 same as Apples, and may be sprayed in the same way. 

 But they have their own particular enemy in the form 

 of the " Pear slug." This can be killed by spraying with 

 one ounce of the commercial nicotine preparation offered 

 for horticultural purposes in a gallon of water. 



In few cases has science found itself so much perplexed 



as in that of the disease known as " silver-leaf," which 



is particularly prevalent on Plums. Comparatively, if 



not wholly, unknown until quite recent years, it is now 



Y 



