42 The Principles of Fruit-growing 



is often washed away or becomes so diluted that the pollen 

 does not germinate. It is probable that the chill of rainy 

 weather decreases the vitality of the pollen and an excess 

 of moisture often causes pollen-grains to swell and burst. 

 Rain also prevents bees and insects from carrying pollen. 



"A temperature low enough to be harmful to blossoms 

 is usually associated with frost or rain ; but a low tempera- 

 ture, even though it does not touch the frost point, nor 

 accompany rain, is often disastrous to the setting of fruit. 

 The injurious effect is probably due to the prevention of 

 the growth of the pollen-tubes." 



Wind. The effects of wind, according to Hedrick, 

 who has studied the question, may be summarized as 

 follows: " Winds whip blossoms from the trees and prevent 

 insects from working. Long continued, warm, dry winds 

 injure blossoms by evaporating the secretion from the 

 stigmas, thereby preventing the retention and germination 

 of pollen. Damp, warm winds, if long continued, are 

 unfavorable to pollination. -A cold, dry, north wind in 

 blooming-time chills vegetation and stops the normal 

 functions of flowers and leaves. On cold, clear nights, 

 winds keep off frosts by renewing the heat; or by bringing 

 fogs or clouds from lakes or ocean, frosts are prevented 

 on the leeward side of the water." In compiling the records 

 of weather in relation to the setting of fruit from 1881 to 

 1905 in New York, Hedrick found that "wind of sufficient 

 strength to damage blossoms" occurred in the years 1881, 

 1882, 1883, and 1895, thus making an element of risk; and, 

 similar risks must be general. 



The disasters from wind often occur in winter when 

 trees are laden with ice; and the damage to ripe or matur- 

 ing fruit is often very great. Protection from high winds, 

 if it can be accomplished without interfering with the 



