SOME CONDITIONS OF FRUIT-SETTING 109 



tion are warmth, sunshine and gentle winds. Such condi- 

 tions favor the expanding of the delicate parts, the shedding 

 of pollen into the air, and also the working of insects among 

 the flowers. I suppose California has a model climate in 

 these respects, which accounts for varieties of fruit which 

 are unproductive on the Atlantic slope, being productive 

 and reliable there. 



But there are two causes which, I believe, with us, are 

 responsible for more losses of tree fruits than are all other 

 causes put together. These are fungus and weakness of 

 bud and pollen. Professor Bailey, who has been studying 

 this same question in connection with the apple orchards 

 of western New York, says: "The immediate cause of most 

 of our apple failures of the last few years is undoubtedly 

 the apple scab fungus. This apple scab is no new pest. 

 It has no doubt been seriously present ever since apples 

 were grown in this country, causing many failures of crops 

 which were laid to the weather or the moon. But within 

 the last decade it seems to have been unusually destructive 

 in the orchards of western New York. The most serious 

 injury wrought by the fungus in western New York in 

 recent years is upon the foliage. Its first visible attack 

 upon the under side of the leaf is simply a light olive 

 green discoloration appearing in small patches, chiefly along 

 the veins, where the disease causes dark, sooty elevations. 

 These attacks cut off the food supply of the parts of the 

 leaf beyond, and the leaf becomes dry and curled. Its edges 

 die and are torn by the wind, giving the tree the blighted 

 appearance which is familiar to all New York apple growers. 

 This condition of the foliage is often serious, even when 

 the apples themselves are very slightly attacked ; and it is 

 sometimes so bad that most of the foliage falls in early 

 summer. It is evident that trees with such foliage as this 

 can neither mature a crop of apples, nor lay up much 

 store of energy for the following year." 



We have the apple scab in Connecticut, we have the 

 dry curled leaves and the effects which follow. The tree 

 with its foliage impaired, no matter what kind of a tree it 

 is, cannot do justice to itself. If it is an apple tree, it 

 cannot mature a crop of apples in good shape, or make 



