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ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



Stigmonose 



This trouble, occurring upon apples and 

 pears. Is caused by Insect punctures. The 

 surface of the fruit shows sharp depres- 

 sions. Cut through the point of one of 

 these pits, the tissue of the flesh shows 

 brown and dry following the track of the 

 puncture. 



Not serious In the Northwest. 



Storage Rots 



These rots of the apple are extremely 

 various, since apples Infected before stor- 

 age are liable to develop during storage 

 the forms of rot due to that infection. 

 Even bitter rot may not be overlooked in 

 this way and much more commonly still, 

 black rot and the rots which develop 

 from the gradual invasion of molds. It 

 is found, furthermore, that bruises upon 

 the apple or any tendency to sun scald 

 phenomena give dead tissues in which 

 various saprophytic organisms that nor- 

 mally hasten decay will do their work 

 with rapidity. It is understood, of course, 

 that the temperatures of storage will reg- 

 ulate or control more or less perfectly 

 the rate of this development. Storage 

 scalding of apples is much worse in some 

 varieties, notably in York Imperial, than 

 In the normal toughened skin types. At 

 present, one can only suggest the rejec- 

 tion of those sorts susceptible to scald 

 for cold storage keeping. 



Sun Scald, Collar Rot 



There is frequent complaint of the 

 dying of the trunk of both younger and 

 older apple trees wherein there appears to 

 be associated the exposure to sun and 

 the death of the bark of the trunk upon 

 younger orchard trees. The freezing in- 

 jury has been carefully worked out in re- 

 cent years with several varieties of 

 apples, notably the Grimes and King. This 

 trouble is so serious as to reduce the 

 growth of these sorts; while Murrill has 

 suggested a connection between a fleshy 

 fungus and this dying of the trunks of 

 the King, the connection has not been 

 proved. The injuries which occur on the 

 south and southwest exposures of the 

 trunk have probably a direct connection 

 with the danger from freezing injuries. 



Some apparent sun scald is more prob- 

 ably due to the bacterium of pear blight 

 as has been recently proved by cultures 

 from young trees by Walte. With Grimes 

 and other varieties susceptible to collar 

 rot caused by the bacterium of pear blight 

 the only true relief is found by top work- 

 ing on some vigorous sort, such as Bald- 

 win, Gano, and like varieties. In the 

 case of true sun scald the effect of freez- 

 ing is to form an ice layer and thus sepa- 

 rate the bark or, in the case of many 

 water-gorged cells, to kill the sap layer. 

 For further discussion in this line see 

 winter injury. 

 See Collar Rot. 



Sun Scald on Fruit 



Accompanied by hardening and crack- 

 ing of skin and tissues of the apple. 

 Sometimes following spraying during hot 

 weather, but by no means always true. 



Syncarpy 



Double or triple fruits caused by the 

 fusion of two or more separate lateral 

 blossom buds. The variation occurs but 

 rarely and is not pathological. 



Twig Blight 



This disease of the apple, caused by 

 the bacterium of pear blight (Bacillus 

 amylovorus Burr.), is often very preva- 

 lent. The microbe enters through the 

 blossoms, being propagated in the nectar 

 after infection by insect visitation. It 

 destroys the blossoms as well as small 

 twigs of the tree. Beyond the injuries 

 just noted this microbe may gain en- 

 trance through the bark. 



See Sun Scald. 



Remedy 



The prevention will lie in the destruc- 

 tion of all the blighted parts on apple, 

 crabapple, pear and quince trees in the 

 vicinity. For fuller discussion see pear 

 blight. In substance, this treatment con- 

 sists in cutting out all blighted portions 

 in fall and early winter and burning them 

 to kill the resting forms of the microbe. 



Variegated Foliage 



Occurs rarely. The leaves of a branch 

 or section of a tree and occasionally the 



