3S9 



PLUM. 



is the same as brown rot of peach, 

 Brown-rot and should be treated in the same 



way. (Fig. 173.) 



This is the same as leaf-spot of 

 Leaf-Spot. cherry and may be controlled by 



two or three appUcations of Bor- 

 deaux, 5-3-50- Make the first one about ten days 

 after the blossoms fall and the others at intervals of 

 about three weeks. This applies to European varie- 

 ties. Japan plums should not be sprayed with Bor- 

 deaux. . See Geneva Bulletins 98 and 117. 



is the same disease as black knot of 

 Black-knot cherries and is controlled ..i same 



way. For control of this disease by 

 spraying see Cornell Bulletin 81. 



Fig. 173- 



Brown-rot 

 plum. 



POTATO. 



There are different kinds of potato blight and rot. The most 

 Blight and rot. important are early blight and late blight — ^both fungous diseases. 



Early blight affects only the foliage. Late blight kills the foliage 

 and often rots the tubers. Two serious troubles often mistaken for blight are : 

 (i) Tip bum, the browning of the tips and margins of the leaves due to dry 

 weather; and (2) flea-beetle injury, in which the leaves show numerous small 

 holes and then dry up. The loss from blight and flea-beetles is enormous — often, 

 one-fourth to one-haU the crop. For blight, rot and flea-beetles spray with Bor- 

 deaux, 5-5-50. For addition of insect poisons see potato flea-beetles. Com- 

 mence when the plants are 6 to 8 inches high and repeat every 10 to 14 days 

 during the season, making 5 to 7 appUcations in all. Use from 40 to 100 gallons 

 per acre at each application. Under conditions exceptionally favorable to blight 

 it will pay to spray as often as once a week. See Geneva Bulletins 10 1, 123, 

 221, 241, 264, 267, 279 and 290. 



is caused by a fungus that 

 Scab attacks the surface of the 



tubers. It is carried over 

 on diseased tubers and in the soil, In general, 

 when land becomes badly infested with scab 

 it is best to plant it with other crops for sev- 

 eral years. See Vermont Bulletin 85 and 

 Maine Bulletin 141. 



QUINCE. 



This is a. fungous disease 

 Leaf and Frtlit producing round, reddish- 

 Spot, brown spots on the leaves 

 andfruit. Spray three times 

 with Bordeaux as for apple and pear scab. 

 See Cornell Bulletin 145. (Fig. 174.) 



Fig. 174. Fruit-spot on quince. 



