278 PLANT DISEASES 



of the i)n'vi()as year and disinfect the stubs with corrosive sub- 

 linialc, 1-1 (K)(). Clean out cankers with a sharp knife, and dis- 

 infect. Paint over with lead paint. At blossoming time make 

 a systematic daily inspection for blossom blight, and break it out. 

 Watch for blight in the shoots. When it appears get a long- 

 handled pruning-liook, fasten a sponge near the knife, and saturate 

 it with corrosive sublimate solution, 1-1000. Clip out the blighted 

 twigs, cutting five or six inches below the blight, and sop the 

 pruned stub with the sponge. During a blight epidemic, drop all 

 other work. The work must be done systematically and per- 

 sistently, or not at all. One week's work may save the pear crop 

 and the pear trees. 



Leaf-bligiit and Cracking of fruit {Fabrea inacxdata). — Attacks 

 nursery stock of pears and quinces, beginning as small circular 

 brown spots on the leaves. These spread, and if numerous cause 

 the leaf to fall. The same disease produces a black spot or pit on 

 the fruit. 



Control. — In nurseries spray with bordeaux mixture, 4-4-50. 

 In the orchard spray as for pear scab, with perhaps one additional 

 application. 



Leaf-spot {Mycosphwrella sentina). — Small lecticular spots with white 

 centers on leaves. Spots become so numerous as to cause defoli- 

 ation. The fungus is known only on leaves, and it winters on them. 

 Control. — Burn fallen leaves. Spray as for Scab. 



Scab ( Venturia pyrina). — Greenish brown or black spots on leaves 

 and fruit, arresting growth and often causing fruit to crack. 

 Severe on Flemish Beauty. Often attacks pedicles of fruits and 

 causes them to drop, and may even cause defoliation. Is different 

 from apple scab, but behaves much like it. Differs especially in 

 the fact that the fungus winters on the twigs as well as on fallen 

 leaves. 



Control. — Owing to the nearness of the fungus (on the twigs) 

 and the slowness with which the pear-leaf unfolds, two applications 

 of spray l)efore the blossoms open are sometimes necessary, and one 

 immediately after they fall. Use lime-sulfur, 1-50, or bordeaux, 

 3-3-50. 



Remarks in regard to apple scab (on page 264) are equally 

 important her*. 



