28 



The first application was made just as the blossoms were separating 

 in the cluster on May 13th; the second, on June 1st, when the petals had 

 all fallen from the trees, and the third application was made on June 18th. 

 A fourth should have been made the last of July for the control of late scab 

 but was omitted because the weather at that time was dry and there was 

 no indication that the scab would become serious. This was an unfortunate 

 decision because the very wet weather which followed in August gave a 

 very serious infection of late scab. 



Rains on May 11th, 12th and 13th, gave an infection of scab on the leaves 

 around the cluster of blossoms but as the blossoms had not separated at 

 that time no infection was present on the fruit stems. Infections occurred 

 during rain periods on June 3rd, 4th and again on the 7th. There were rains 

 on June 19th and 20th but fortunately the applications had been made the 

 day previous. 



Bud-moth and cigar-case bearers were fairly abundant early in the 

 season. Leaf-roller was present and on June 1st the caterpillars had begun 

 to eat the stamens and calyx lobes of the newly set apples. They were aided 

 considerably in this work by the green fruit-worms. Codling moth was 

 unusually scarce in this orchard as is shown by the count of the apples from 

 the untreated plat, only about one per cent being infested. 



In determining the degree of control, all the apples on three trees 

 chosen from near the center of each block were examined and the injuries 

 recorded on counting machines. The results are indicated in the following 

 table :— 



Treatment 



Untreated 



Lime-sulfur solution 



Sulfur 80%, Arsenate of lead 



20% 3.8 14.0 8.5 .3 



Sulfur 40%, Arsenate of lead 



10%, Gypsum 50%o 4.1 15.4 8.0 .01 



Sulfur 40%, Arsenate of lead 



10%, Hydrated Lime 50%. 9.0 37.1 11.3 .17 



From this table it will be seen that all the dust mixtures, except where 

 lime was used as a diluent, gave better protection for the control of early 

 infections of apple scab, than did the lime-sulfur solution. As previously 

 stated, no application was made the last of July for the prevention of late 

 scab and the data in regard to its prevalence are of interest only as showing 



