134 



MASS. EXPERIMENT STATION BULLETIN 254 



they did not recover and also from inability to control the striped beetles and 

 accompanying mosaic. The cucumbers were inoculated with a spore suspension 

 of anthracnose, Colletolrichum lagenarium (Pass.) Ells, and Hals., on July 21, and 

 leaf counts made on August 11. 



Spray . 

 Dust . . 

 Check . 



Dr. Guba reported that it was impossible to maintain protection this season due 

 to continuous heavy rains. The dust, however, appears to have afforded slight 

 protection. 



Celery 



Three plots, 120 by 12 feet, of 4 rows, 3 feet apart, each, were employed. The 

 spray consisted of basic sulfate (lot 5) and raw linseed oil 2-0.5 pt.-50 and contained 

 about 0.26 per cent copper. The oil proved unsatisfactory but was omitted only 

 on August 26. The dust consisted of basic sulfate (lot 5) and talc and contained 

 about 7.02 per cent copper. Treatments were made on August 10, 17 and 26 

 and September 2, 12 and 20. The celery was inoculated with a spore suspension 

 of early and late blights on August 26, boarded on September 26, harvested on 

 October 14 to 16 and the yield of marketable celery determined. 



Table 6. Effect of Basic Copper Sulfate on the Yield and Grade of Celery 



Increase 

 Number over 



Form of application Copper of Number of Bunches check 



content appli- Grade 1 Grade 2 Total Total 



cations bunches 



Per cent Per cent 



Spray 0.26 6 163 45 208 38.67 



Dust 7.02 6 192 26 218 U5.33 



Check 0.00 93 57 150 



Grade 1: 3 good siz^d stalks to the bunch, 18 bunches to the box. 

 Grade 2: 4-7 small stalks to the bunch, 18 bunches to the box. 



The yield and the grade were increased by the use of basic sulfate, particularly 

 the dust. 



Potatoes 



Dusting experiments were conducted on the Station rotation 0.05 acre plots Nos. 

 7, 17, 53, 54 and 55 and 0.03 acre intervening strips under the supervision of 

 J. P. Jones to determine the effectiveness of basic copper sulfate in controlling 

 early and late blight on potatoes. The seed was Massachusetts certified Green 

 Mountain, grown in Charlemont and disinfected with corrosive sublimate. 

 The seed was planted on May 7, and the crop harvested on September 16. The 

 cultural and fertilizer treatment was of the usual character. The plots were 

 dusted on June 16 and 25, July 1, 8, 19 and 29 and August 6 with a mixture of basic 

 sulfate (lot 5), lead arsenate and talc containing about 7.52 per cent copper and 



