ANNUAL REPORT, 1934 33 



on adjacent unsprayed plots. Only 22 to 27 percent of the terminal buds on vines 

 on the sprayed plots were killed and very little defoliation occurred. 



Determinations of the oxygen content of flooding water in relation to bud and 

 tip injury were made on a few bogs which were flooded in June. Low oxygen 

 content of the water was found on one bog only. On this bog the oxygen content 

 was below 1.5 mis. per liter over a period of 12 to 14 hours. On most parts of the 

 bog flower buds were not sufficiently developed to be injured, but where more 

 advanced about half of the buds were injured. 



Regeneration of Bogs Infected with False Blossom. (H. F. Bergman.) About 

 0.2 acre of bog planted with Howes, with a moderate infection of false blossom 

 and very weedy, was sprayed July 31 with a solution of sodium arsenite containing 



8 pounds of this chemical dissolved in 100 gallons of water and applied at the 

 rate of 1000 gallons per acre. Another part with an area of 0.3 acre was sprayed 

 with a sodium arsenite solution of the same strength but containing 12J^ pounds 

 of sodium bisulfite per hundred gallons of solution. Both solutions killed vines 

 and weeds down to the ground but failed to penetrate into underground portions 

 and kill them. New growth from underground parts of cranberry vines and weeds 

 was observed in September. 



Spraying and Dusting Experiments. (H. F. Bergman and W. E. Truran.) 

 Bordeaux made up by the 4-4-50 formula, with chemically hydrated lime, and 

 applied at the rate of 350 to 400 gallons per acre was used on three bogs. Two 

 mercurial sprays were used on one bog. Both mercurials were made up in two 

 strengths: Y<i pound and 1 pound to 50 gallons of water. The rate of application 

 was the same as with Bordeaux. Only two applications of any of these sprays 

 were made during the season. The amount of rot in berries from sprayed plots, 

 with few exceptions, was reduced to half or less of that in berries from unsprayed 

 plots. On one bog of Howes, two applications of Bordeaux had no apparent 

 effect in reducing rots. The mercurial sprays reduced rots to about the same 

 extent as Bordeaux. 



An experiment on the use of mercurial dusts mixed with pyrethrum dust as a 

 combined fungicide and insecticide was carried out in cooperation with Dr. 

 H. J. Franklin. The mixtures were made up to give two different strengths of 

 fungicide: one containing 1 pound of mercurial, 4 pounds of pyrethrum, and 



9 pounds of gypsum; the other containing 2-4-8 pounds, respectively, of these 

 ingredients. Two replications of two plots each were dusted with 7 pounds of 

 dust of each strength for both mercurials. A check plot alternated with each 

 dusted plot. The dust was applied June 21, at which time the earliest flower buds 

 were just ready to open. Within two to three days after the dust was applied 

 the leaves of vines on the dusted plots began to turn yellow. This was most 

 marked on plots which had been dusted with mixtures containing two pounds of 

 mercurial. The yellowing of the leaves reached a maximum in about a week, 

 thereafter diminishing gradually, but was noticeable as late as September 1. 

 On two plots, each dusted with two pounds of one of the mercurials, a consid- 

 erable number of buds, flowers, young fruits, and tips of vines were killed. The 

 yield of these two plots was reduced to one-third to one-half that of check plots. 

 The amount of loss due to fungous rots in berries from plots which had been 

 dusted with two pounds of mercurial was materially reduced as compared with 

 that of berries from adjacent check plots. Some reduction in the amount of rot 

 was effected by dusting with a mixture containing one pound of mercurial but 

 this was not as effective as that containing two pounds. 



