Pollination in Orchards. 



365 



OlPSi 



Blossoms May Be Killed by Fungi. 



If the weather is warm and wet in early spring, conditions are 

 favorable for the growth of fungi and it sometimes happens that 

 fruit blossoms are " blasted " by the early growth 

 of these parasites. The common brown rot fun- 

 gus often kills peach blossoms and may seriously 

 decrease tlie setting of fruit. It is probable that 

 this fungus sometimes attacks plum and cherry 

 blossoms also. Apple and pear scab may kill the 

 blossoms, but more often it kills the young a-uits 

 soon after they are set. Wherever spraying is 

 practiced faithfully, the killing of fruit blossoms 

 by fungi need not occur, especially if one thor- 

 ough application is made to the trees before the 

 buds open. The killing of pear blossoms by 

 blight, however, cannot be prevented by spray- 

 ing. The blossoms on Kieffer and LeConte 

 trees are especially liable to be destroyed by the 

 growth of blight microbes, which are carried 

 from flower to flower. The only way to pre- 

 vent this loss is to have no blighted trees in or 

 near the orchard. 



72. — Winter -injured 

 fruit buds of Royal 

 apricot. 



Winter and Spring Frost May Injure the 



Blossoms. 



The unfruitfulness arising from winter or 

 spring frost injury is sometimes confused with 



self-sterility. Various forms of winter 

 injury to fruit buds are shown in Figs. 

 72-77. At A in Fig. 72 is a fruit bud 

 which has been completely winter-killed 

 and has made no growth whatever. B 

 and C are buds which will never be able 

 to open ; while D is a very weak blossom 



IZ.— Winter-ivjured fruit buds ^hich cannot set fruit. The single open 



of Biet iqheimer apple. n ,1 • i ^ • ,^ ^ 



nower on this branch is the only one 



which can possibly set fruit. A winter-injured cluster of Bietig- 



heimer blossoms is seen in Fig. 73, with a section of one bud in Fig. 



