Spraying for Black Spot of the Apple. 359 



In the case of the Beurre Bosc pears sprayed on 24th September, 

 1902, some of the mixture afterwards showed on top of the spot. On 

 9th October black spot was extremely common on fruits, fruit stalks, 

 and young leaves, when petals had mostly fallen. On another 

 variety growing alongside, name unknown, the black spot was fairly 

 plentiful on the same day, 9th October, though at that time the petals 

 had not quite half fallen, and many flowers were not yet open. Many 

 individual flowers and stalks were plucked, showing the spot before 

 the petals had expanded. Some of these were brought away to be 

 photographed, but unfortunately before this could be done the petals 

 had withered and dropped oft'. 



These facts, liowever, show that the first infections of the young 

 leaves and flower stalks of the pear must have occurred in the case of 

 the Bosc, prior to the 24!th of September, and in the other varietv 

 probably a few days later. There seems then no escape from the 

 conclusion that the first spraying of pears must be done as soon as the 

 first blooms begin to expand, and probably if this were followed up 

 by another about ten days later, when the tree would be just about in 

 full bloom, the maximum beneficial results would be obtained. It 

 seems doubtful if the black spot of the pear can be so successfully 

 controlled by one spraying as is done with apples, but further 

 experiments are needed to settle this point. In any case, as the 

 blossoming of the pear is spread over a lengthy period, usually 

 marked by mucli rain and heavy dews, conditions extremely favourable 

 to the germination and growth of the spores of the fungus, conditions 

 also tending to wash off the spraying material, the advisability of two 

 applications of B(jrdeaux as before suggested is strongly urged upon 

 growers. 



Spraying in Bloom. 



A good deal has been written about spraying fruit trees in bloom 

 of a somewhat contradictory character, and it is advisable therefore 

 to state the experience of the past season. When an apple blossom 

 fully expanded was carefully sprayed with an atomiser, so that every 

 portion received the spray, no fruit set, presumably because the top 

 of the stigma was rendered unfit for the germination of the 

 pollen grain either ah-eady u])on it or afterwards to be carried there. 

 But when a large tree with the blossoms fully expanded was sprayed 

 with a light and fine spray, then the fruit set very well, and no 

 apparent damage was done. With such a mass of blossom as a 

 healthy tree usually bears, a very fine spray distributed over such an 

 extensive surface is not dejjosited in large quantity at any particular 

 spot, and the number of stigmas rendered unfit to receive or retain 

 the pollen is very small in comparison with the total number, and so 

 the yield is not apparently affected. While it may be quite safe to 

 spray a fruit tree when in full bloom, provided it is done in the form 

 of a very fine mist, yet when one spraying alone is given it is not 

 altogether advisable to do so for various reasons, unless weather con- 

 ditions have prevented the operation being performed earlier. 



