32 MASS. EXPERIMENT STATION BULLETIN 315 



of Sandwich, and the west part of Barnstable. It was so severe in places in Sand- 

 wish, Mashpee and around Cotuit that all forest undergrowth was completely 

 defoliated and turned brown. The worms were abundant for only a mile or two 

 east of Hyannis and were not found much west of the main highway running from 

 Bourne to Falmouth. They did considerable injury on some cranberry bogs 

 around Waquoit and in Mashpee and seriously harmed some strawberry patches 

 in East Falmouth. They usually defoliated withe-rod ( Viburnum cassinoides) 

 and wild indigo (Baptisia tinctoria), evidently being especially fond of them. The 

 following plants were seriously attacked generally: Black huckleberry, dangle- 

 berry, scrub oak, willow, wild lupine (Lupin us perennis), beach plum (Primus 

 maritima), wild black cherry, and locust (Robinia sp.). 



Datanas. Datana caterpillars were so abundant on small patches of a bog in 

 Plympton that they defoliated the vines. They were fully grown on the bog on 

 July 20, 1934. A lot of them pupated in confinement on July 30 and 31. The 

 species was identified from the caterpillars by Mr. Carl Heinrich of the Bureau of 

 Entomology, U. S. D. A., as Datana drexelii Hy. Edw. 



COOPERATIVE CRANBERRY INVESTIGATIONS 



Conducted by the Bureau of Plant Industry, United States Department of Agri- 

 culture, in cooperation with the Massachusetts Agricultural 

 Experiment Station 



H. F. Bergman, Senior Pathologist, U. S. D. A., in Charge 



Development of Strains of Cranberry Resistant to False Blossom. (H. F. 



Bergman and W. E. Truran.) Nearly 500 cross pollinations were made during 

 the past season. These include Early Black x Shaw's Success, Centennial x Early 

 Black, Paradise Meadow x Early Black, and reciprocal crosses between Early 

 Black and McFarlin and between Shaw's Success and McFarlin. Although the 

 season was very unfavorable, 25 to 50 percent of the pollinated flowers produced 

 fruit. The best results were secured in crosses of McFarlin by Early Black, in 

 which 48.4 percent of the pollinated flowers developed fruit. Only 24.5 percent 

 of the flowers of Centennial pollinated by Early Black matured fruit. 



Oxygen Content of Flooding Water in Relation to Injury to Cranberry Vines* 



(H. F. Bergman and W. E. Truran.) Observations were made on a number of 

 bogs to determine the extent of injury to vines in relation to the depth of the 

 winter flood. On some of these bogs the winter flood was let off in April and 

 on others it was held until May 20 to 23. No differences were observed in the 

 extent of injury to vines on bogs on which the water was held late as compared 

 with those on which it was let off in April. The amount of injury is directly re- 

 lated to the depth of the winter flood, but depends also upon the character of 

 water supply, density of vine growth, and amount of organic matter in the sub- 

 stratum. Injury ranged from mere retardation in development to death of a 

 large proportion of terminal buds with severe defoliation. On one bog where the 

 winter flood was held until May 23, 60 to 70 percent of the terminal buds were 

 killed on the most deeply flooded areas where the water was 3 to 4 feet deep. 

 On the same bog where the water was not more than 6 to 8 inches deep, only 3.3 

 percent of the terminal buds were killed. On plots in the most deeply flooded 

 area, which had been sprayed with Bordeaux two or three times during the pre- 

 ceding summer, the vines came through in much better condition than the vines 



