TiiK Control of Ixskct Pests and Plant DLsiiL<\si;s. 



609 



pletely controlled by spraying the trees once, 

 before the buds swell, with Bordeaux, 5-5-50, or 

 with the lime-suh'ur mixtures used for San ]os6 

 scale (see under fungicide, page 500). Cornell 

 Bulletin 276. 



Yellows is a so-called "physio- 

 YellowS. logical disease." Cause un- 

 known. Contagious and quite 

 serious in some localities. Known by the pre- 

 mature ripening of the fruit, by red streaks and 

 spots in the fruit liesh and by the peculiar 

 clusters of sickly, yellowish shoots that appear 

 on the limbs here and there. Eradication is 

 the only means of control. Dig out and bum 

 diseased trees as soon as discovered. 



Fig. 217. Black-spot on peach. 



Fire-blight. 



Scab. 



Fig. 218. 



PEAR. 

 This is the same as fire-blight of apple but it is more destructive 

 to pears. It kills the twigs and branches on which the leaves 

 suddenly blacken and die but do 

 not fall. It also produces cankers on the trunk and 

 large limbs. Prune out blighted branches as soon as 

 discovered, cutting 6 to 8 inches below the lowest evi- 

 dences of the disease. Disinfect with corrosive subli- 

 mate solution, I to 1000. Clean out limb and body 

 cankers as described for fire-blight on apple trees, 

 Disinfect all large wounds and cover with coat of paint 

 or gas tar. Cornell Bulletin 272. Plant the varieties 

 least affected. 



Scab is a fungous disease very similar 

 to apple scab, but it is not the same. 

 It is very destructive to some vari- 

 eties, as, for example, Flemish Beauty 

 and Seckel. Spray three times with lime-sulfur, 1-50 

 (32® Beaum^), or Bordeaux, 3-3-50, as for apple scab 

 (page 486). Cornell Bulletin 145 and Geneva Bulletins 

 67 and 84. 



PLUM. 

 This is the same disease as black-knot 

 of cherries and is controlled in same 

 way. (Page 489.) 

 This is the same as brown-rot of 

 peach, and should be treated in the 

 same way. (Page 494.) 

 This is the same as leaf-spot of 

 cherry and may be controlled by 

 two or three ay)plications of self- 

 boiled lime-sulfur or Bordeaux, 

 2_2-5o. Make the first one about ten days after the 

 blossoms fall and the others at intervals of about three 

 20 



Fig. 218. Pear-scab. 



Black-knot. 



Brown-rot 

 Fig. 219. 



Leaf-spot. 



Fig. 



219. Brown-rot on 

 plum. 



