ANNUAL REPORT, 1932 61 



During September some fifty selections of wild cranberries were made in Maine. 

 These selected wild vines were taken to P3ast Wareham where they are being hekl 

 over winter to be propagated in 1933. Several of the selected wild vines show 

 very desirable vine and fruit characteristics. 



Oxygen Content of Flooding Water in Relation to Injury to Cranberry 

 Vines. (H. F. Bergman and \V. E. Truran.) Some experiments to determine 

 the efTect of absence of oxygen in winter-flooding water on the development of 

 terminal and fruiting buds during the following growing season failed because 

 of unfavorable weather conditions. Several hundred buds of Early Blacks and 

 Howes on the State Bog were tagged and their development was followed through 

 the season. Large terminal buds tended to produce more fruits than either medium 

 or small terminal buds. This tendency was more evident in Howes than in Early 

 Blacks. 



Regeneration of False Blossom Bogs. (H. F. Bergman and Jos. L. Kelley.) 

 In cooperation with growers, two areas of bog badly infested with false blossom 

 were sprayed in July with commercial weed killer (probably sodium arsenite) 

 diluted 1:30 and applied at the rate of 600 to 800 gallons per acre. This treat- 

 ment appears to be very satisfactory. 



June Flooding for Fireworm Control. (H. F. Bergman, W. E. Truran, 

 and Jos. L. Keiley.) Severe injury to flower buds ami growing tips, due to low 

 oxygen content in the flooding water, was observed in one bog during the flooding 

 period for fireworm control. The lowest oxygen content found was 1.9 cc. per 

 liter. Firewornis were apparently completely killed. No injury was observed 

 on two other bogs. From experiments it appears that firewornis can be killed 

 by submergence for 12 hours in water at a temperature of 15° to 20° ("., and an 

 oxygen content of less than 4 cc. per liter. An oxj'gen content of less than 1.0 cc. 

 per liter for 5 to 6 hours causes injury to flower buds and growing tips. 



June Flooding for Leafhopper Control. (H. F. Bergman and W. E. Tru- 

 ran.) Flooding for 16 to 18 hours killed about 75 per cent of the leafhoppers on 

 one bog. The oxygen content of the water tlid not fall below 3.5 cc. per liter. 

 No bud injury was observed. Flooding for 12 to 15 hours, on another bog, killed 

 only about 50 per cent of the leafhoppers. The lowest oxygen values here were 

 3.5 to 4.0 cc. per liter. 



Investigations on the Effect of Copper Residues from Bordeaux Spray 

 on the Growth of Cranberry Vines. (H. F. Bergman and W. E. Truran.) 

 The greatest amount of copper, which varies from 150 to 200 milligrams per kilo- 

 gram of dry soil, is found in heavily sprayed bogs with a peat substratum. There 

 is much less copper in soils of very wet bogs and of those with a sand substratum. 

 The amount of copper in vines varies from 50 to 100 milligrams per kilogram of 

 dry vines. The leaves ordinarily contain one and one-half to two times as much 

 copper as the stems, for the same weight of material. In one experiment copper 

 sulfate was applied directly to the soil in amounts equivalent to 800, 1200, 1600, 

 and 2400 pounds per acre, without injury to the \ines and with no apparent 

 reduction in yield. 



Spraying Experiments with Bordeaux and Organic Mercurial Sprays. 



(H. F. Bergman, W. E. Truran, and Jos. L. Kelley.) Spray plots were located 

 on four separate bogs. 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 

 all bogs. Two organic mercurial sprays were used on one bog. The reduction 



