138 MASS. EXPERIMENT STATION BULLETIN 254 



at any time to constitute a real test of the fungicides. The fruit was of good 

 quality from all vines including the checks, and there seemed to be no appreciable 

 injury from the various treatments. The yields are not reported on account of 

 pilfering of the fruit. 



Field Work in 1928 



The field work of 1928 with basic sulfate includes experiments with celery on the 

 vegetable garden plots at the College, with potatoes on the Experiment Station 

 plots and on the College farm, and with apples and grapes in the College orchard 

 and vineyard. Low and high basic sulfates were employed in both spray and dust 

 applications. 



Celery 



Spraying and dusting experiments were conducted on the College grounds, 

 under the supervision of G. C. Stout, to determine the relative effectiveness of 

 low and high basic sulfates (lots 6 and 7), Bordeaux 4-4-50 and a commercial 

 monohydrated copper sulfate-hydrated lime dust (copper-lime dust) in controlling 

 early and late blights on celery. The basic sulfates with raw linseed oil 1.25 pts.-50 

 as a spreader and sticker were applied as sprays at a concentration of 0.24 per cent 

 copper, the same as Bordeaux 4-4-50. The basic sulfates mixed with a free- 

 flowing talc were applied as dusts which contained 6.80 per cent copper, the same 

 as the guarantee of the copper-lime dust. The sprays were appUed with a barrel 

 pump under about 75 pounds pressure and the dusts with a Niagara hand duster. 

 The field was divided into plots of 4 rows each to which the several fungicides were 

 applied, and 2\ rows for checks. The celery plants (Giant Pascal) were set rather 

 late and made a poor growth due to unfavorable weather conditions. The fungi- 

 cides were applied on July 30, August 9, 21 and 31 and September 28. Doran 

 observed late blight on August 18 but no difference between plots. On October 

 29 there was late blight on the older leaves of all plots. No copper injury was 

 noted. From general appearance the sprays were the most effective, followed 

 by the dusts and checks. Bourne observed a few plant lice equally distrib- 

 uted. The celery [did not reach marketable size, but the two middle rows of 

 each plot were pulled and weighed for yield records. 



Table 8. Relative Effectiveness of Low and High Basic Sulfates, Bordeaux and Copper- 

 lime Dust in Controlling Early and Late Blights of Celery, — As Shown by Yields 



Number 

 Copper of Increase 



Fungicide content appli- Yield over 



cations check 



Per cent Lbs, Per cent 



Low basic sulfate spray 0.2i 5 206 n5.2i 



High basic sulfate spray O.U 5 228 171.i3 



Bordeaux 4-4-50 0.2i. 5 273 105.95 



Check (one row only) 0.00 42 



Low basic sulfate dust 6.80 5 94 20.51 



High basic sulfate dust 6.80 5 102 S0.77 



Commercial copper-lime dust 6.80 5 138 76.92 



Check (one row only) 0.00 39 



There were no replications and the plots suffered unequally from adverse 

 weather conditions so that the experiment has little significance except to indicate 

 that 0.24 per cent sprays were more effective than 6.80 per cent dusts. 



