Symptoms 



Pear. 



Foliage. — Leavea distorted with blisters, 

 hollow below, the interior of the hollow being 

 whitish. Due to Exoascus hullatus (not to be 

 confused with pear-leaf blister mite (p. 114)). 

 Spray with Bordeaux mixture (7). 



Fruit. — See Apple. Scab in the case of the 

 pear is due to Venturia pirina ( = Fusicladium 

 pirinum). Treatment as for apple scab. 



[Note. — ^Foliage, especially of soft shoots, 

 turns suddenly brown, although hitherto in 

 apparently vigorous health ; black sticky fluid 

 exudes from bark. Fire-bUght, an American 

 disease, for which watch should be kept, due 

 to Bacillus amylovorus. Carried by insects. 

 Burn all infected shoots and disinfect knife 

 used in pruning, before and after each 

 cut.] 

 Pblaegonitjm. 



Stem becomes blackened and decays ; leaves 

 turn yellow ; pale spots, sometimes flesh- 

 coloured, appear on blackened portion of stem. 

 Stem-rot described by Dr. Cooke as due to 

 Fusarium Pelargonii. Destroy plants. 



[Grey mould (Botrytis cinerea) often appears 

 on dying foliage and shoots of Pelargoniums. 

 A drier atmosphere and less close conditions 

 should be maintained, and aU decaying leaves, 

 etc., burned.] 



90 



