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THE FRUIT GROWER'S GUIDE. 



affections afflict both apple and pear trees, the smaller branches and twigs having scaly 

 swellings partly or wholly encircling them. These swollen parts may be caused by the 

 poison of a gall-producing insect, the ravages of fungi, or a chemical change in the 

 nature of the sap. Canker is generally attributed to ill-nutrition, cold, wet, and heavy 

 soils. Whatever is amiss with the soil and the management must be rectified before 

 improvement can be looked for in the trees. (See " Canker," Vol. I., page 229.) 



Spot on Shoots and Leaves. This is caused by a fungus, Ecestelia cancellata, Eeb. 

 (see Fig. 40). Its appearance on the leaves consists of large raised spots or patches, 

 yellow at first, but soon becoming red, and visible on both surfaces. The peridia, 



Fig. 40. R(ESTELIA CANCELLATA ON PEAR LEAP AND STEM. SECTION OF LEAF BELOW, WITH PEBIDIA ENLARGED 



FOUR IN ELEVATION, TWO IN SECTION. 



situated on the lower surface, contain minute spores, which escape when mature. These 

 spores are believed to be the cause of the fungus (Gymnosporangium Sabinse) found 

 on savin (Juniperus Sabina), and the spores of the latter fungus give rise to the 

 Eosstelia cancellata on pear growths. Savin, therefore, ought not to be grown near pear 

 trees. All diseased pear leaves should be removed directly they become spotted or 

 blotched with red, and burned. This must be done before the spores are dispersed. 

 The only preventive is to spray the trees as advised for " cracking in pears." 



Cracking in Pears. The typical form of the fungus causing " cracking " in apples 

 is Cladosporium (Fusicladium) dendriticum, and is fully described in Vol. I., page 238. 



