DETERMINING TIME OF APPLICATION 299 



and the bud-moth larvae. If the trees have been sprayed previously 

 at the dormant or green-tip stage for these pests, the nicotine may be 

 omitted in the delayed-dormant application. The nicotine may also 

 be omitted on non-aphis-susceptible varieties, such as Mcintosh, unless 

 bud moth is a problem. 



For the nicotine spray to be most effective against the rosy aphis, it 

 is necessary to delay spraying until nearly all the eggs have hatched. 

 Under normal weather conditions this has taken place by the time the 

 opening leaves have reached the stage indicated, and that is usually 

 early enough for scab control. In exceptional seasons, however, apple- 

 scab infection may occur before the aphis eggs have hatched. Under 

 such circumstances Bordeaux mixture in the green-tip application, or an 

 additional early application of 2 gallons of lime-sulfur, may be re- 

 quired for scab control before the delayed-dormant spray. 



Some growers prefer to apply the oil spray at the delayed-dormant 

 stage instead of the dormant or green-tip stage for the control of scale 

 and red mite. The spray should be completed before the leaves roll 

 back and expose the blossom buds, to avoid the danger of russeting the 

 fruit. 



Pre-Blossom Sprays 



, Lime-sulfur 2 gallons 



The same suggestions relative to lime and lignin-pitch as those men- 

 tioned under the delayed-dormant spray are followed. 



It is advisable to increase the lead arsenate and lime to 6 pounds 

 each if leaf-roller is a serious problem. 



If dust is used, a 90-10 sulfur-lead-arsenate mixture is indicated. If 

 conditions are favorable for severe scab infection, the grower should 

 spray as much as possible, using dust to complete the operation on time. 



The pre-blossom spray or sprays, applied between the delayed- 

 dormant spray and the bloom, are timed primarily for scab control. 

 The points to be considered in timing the applications are: the occur- 

 rence of rain periods; the amount of new growth; and the stage of 

 development of the scab fungus. In some seasons two pre-blossom 

 applications may be required for effective scab control, especially on 

 extremely susceptible varieties such as Mcintosh. 



Calyx-Spray (when the last of the petals are falling) 



Lead arsenate . . 

 Water to make 



3 pounds 

 100 gallons 



Lime-sulfur . . . 

 Lead arsenate . , 

 Nicotine sulfate 

 Water to make 



100 gallons 



2 gallons 



3 pounds 

 1 pint 



