142 MASS. EXPERIMENT STATION BULLETIN 254 



The several dusts were applied every week from June 22 to September 8, 

 twelve treatments. With the exception of the last treatment rain fell within two 

 days following the apphcation, removing most of the dust. The first 6 treatments 

 contained arsenic which was omitted on August 3 and thereafter except on August 

 23 when the basic sulfates with lead arsenate were applied. Lead arsenate 

 and talc were applied 8 times to the checks which was probably more than was 

 needed. A method of weekly applications is a systematic procedure that is 

 apparently unnecessary early in the season except possibly of lead arsenate for 

 insects, but more frequent applications later in the season following rains might 

 prove more effective in controlling blight (Jones). Doran observed some early 

 and late blights and tipburn on August 17 and considerable late bhght on Septem- 

 ber 10. The yield records were determined from the two middle rows of every 

 4-row section except the one-half outside sections of Field B, of which both rows 

 were taken. 



All the dusts reduced the amount of rot, but the low basic sulfate proved slightly 

 the most effective in this respect. The physical characteristics of fungicides are a 

 factor in the flow and economical coverage when appUed as a dust. Neither of the 

 basic sulfates was suitable for application in this form, while the copper-lime dust 

 was light, bulky and of good flow. 



.4 pples 

 A spraying experiment was conducted on Block B of the Station orchard under 

 the supervision of J. K. Shaw and W. A. Cutler, to determine the relative effective- 

 ness of low and high basic sulfates and Ume-sulfur in controlling diseases, primarily 

 scab, on Mcintosh and Red Astrachan apples, and the amount of injury to foliage 

 and fruit. The basic sulfates (lots 6 and 7) with lead arsenate and raw linseed oil 

 1.50-0.50 pt.-50 were appUed at a concentration of about 0.07 per cent copper 

 and 0.071 per cent arsenic. A standard mixture of Ume-sulfur (33°B) and lead 

 arsenate 1.25 gals.-1.50-.50 was employed for comparative purposes. The sprays 

 were applied with a Friend power sprayer with 2.50-gallon tank, under 275 pounds 

 pressure, and Friend guns with 3/32 disc nozzles. In the pre-pink spray (May 2) 

 and pink spray (May 9) the basic sulfates injured the fruit buds a little more than 

 lime-sulfur. In the calyx spray (May 24) the basic sulfates injured the fruit to 

 some extent, as considerable russeting was observed later, but failed to control 

 scab. Lime-sulfur also gave poor control but proved superior to the basic sulfates 

 and caused less injury. The copper sprays mixed well and their adherence was 

 very good (Cutler). Doran made the following observations as to injury and scab 

 on foliage. 



Table 11. Relative Effectiveness of Lovir and High Basic Sulfates and Lime-sulfur in 



Controlling Scab on Mcintosh and Red Astrachan Apples, and the 



Amount of Injury,— As Shown by the Foliage 



Plot Fungicide June 14 July 16 



1 Low basic sulfate Leaves yellow and falling badly. Trees defoliated. 



Not much scab. Fruit russeted. 



2 High basic sulfate Leaves yellow and falling badly. Trees defoliated. 



Not much scab. Fruit russeted. 



3 Lime-sulfur Leaf injury negligible. No leaf injury. 



Not much scab. Fruit not russeted. 



Doran noted practically no injury to apple foliage from lime-sulfur, but the 

 basic sulfates defohated the trees seriously and russeted the fruit. The fohage 

 of the Red Astrachan was injured more than that of the Mcintosh. 



