250 MASS. EXPERIMENT STATION BULLETIN 271 



eiahteen liours killed them all. It apiicar.s, therefore, that these pe.st.s can 

 be controlled more safely by flooding in .Tune than ha.s heretofore been 

 thought po.ssible. 



In cooperation with the Bureau of Plant Industry, a very satisfactory 

 chemical color test was developed for determining roughly the oxygen 

 content of water used in bog flooding. This test is so simple that it may 

 be used readily by cranberry growers. 



Cranberry Disease Work. (H. J. Franklin in cooperation with the 

 Bureau of Plant Industry, U. S. D. A.). Forecasts of the very poor 

 keeping quality of the fruit of the 1930 cranberry crop were made by the 

 station. They were based on we;ither records and incubator tests and 

 proved to be timely and accurate. 



Weather Observations. (H. J. Franklin). Local weather observations 

 were made and reported to the office of the Weather Bureau at Boston, 

 and further records bearing on frost forecasting were gathered from 

 various special stations as in previous years. 



Forecasts of minimum bog temperatures were made in the frost sea- 

 sons in the early afternoon and early evening and distributed by telephone 

 as heretofore. Frost conditions were so accurately determined that flood- 

 ing for frost protection was not once begun unnecessarily at the station 

 bog, and three of the four times that such flooding was done there the 

 water was started on in the middle of the afternoon. No one ever re- 

 mained at the station to watch conditions after the early evenin|g observa- 

 tions were made, and the amount of injury to the bog from frost was 

 negligible. 



Southeastern Massachusetts, in common with much of the rest of the 

 country, had the worst drought during July that it has experienced in a 

 great many years. Advantage was taken of this to gain information about 

 the effects of drought on cranberry fruiting. For this purpose plots were 

 laid off on Early Black and Howes sections on the station bog and were 

 watered with about two inches of water once a week during the drought 

 period. The water was put on with a hose, the open end of which was 

 pushed in among the vines at intervals so as to wet the soil well without 

 wetting the vines. The berries from these plots and from unwatered 

 checks near them were picked on the following dates: Early Black variety 

 on September 6; Howes variety on September 18. The berries from tlie 

 watered areas were notably larger in all cases than were those from the 

 checks, as shown by the following average cup counts (the inspectors' 

 cup of the New England Cranberry Sales Co. being used) : 



Variety Cup Counts 



Watered Areas Checks 



Early Black 114 140 



Howes 14-5 16.5 



The average quantity of fruit per unit of area was .50 per cent greater 

 by weight and 55 per cent greater by volume from the watered areas than 

 from their checks. The berries from the watered areas had a much better 

 color than those from the checks and were evidently fully ten daj^s ahead 

 in ripening. 



Varieties. (H. J. Franklin). The study of cranberry varieties, their 



