CRANBERRY STATION. 167 



floodings are about the longest in the year. In clear weather they allow 

 photosjTithesis to go on about fifteen hours of the twenty-four, the ox\'gen 

 in the water thus being replenished three-fifths of the time. 



From what is kno's\ai about the effect of temperature with other species, ' 

 a rise of 18° F. must more than double the rate of respiration in the neAV 

 growth of cranberry. Therefore a combination of very cloudy weather 

 with a high water temperature seems especially dangerous in the flooding 

 of actively growing vines; for, while the stopping of photos,ynthesis allows 

 the ox.ygen in the water to become much reduced, the high temperature 

 greatlj' increases the need of the plants for oxygen. This was the weather 

 combination of June 17. As alreadj^ stated, the day was darkly cloudy. 

 It was also warm for a cloudj^ day, the temperature at the station bog 

 reaching 77° F.; also, as the 14th, loth and 16th had been warm daj's 

 ■with warm nights, the water must have become quite warm before it was 

 put on the bog. That warm water is not notably harmful in cranberry 

 flooding in clear weather is explained by the fact that a rise in tempera- 

 ture, with light abundant, increases the rate of photosynthesis almost as 

 much as that of respiration.^ 



Water Injuries to Crvnberry Buds. 



When, in flooding, cranberry blossom buds are hurt by droAvning (lack 

 of oxygen) they usually are either entirely killed, the whole bud turning 

 brown and never opening, or they are injured only on one side, in which 

 case the point of the bud soon bends toward the hurt side, and one or two 

 lobes of the corolla commonlj^ turn bro\\Ti. When but one side of the bud 

 is hurt it usually opens to form an imperfect blossom, but rarely develops 

 a beny. ^ When this drowning injury occurs it is severest in the deepest 

 water and on the sides of the ditches. 



Another bud injury was observed in 1919 in connection with the flood- 

 ing of three bogs located near together. The berries on these bogs are 

 Early Black, and the water for flooding them all has the same source. All 

 three bogs were flooded before sunrise June 12. The water was let off the 

 two lower ones on the night of June 13, the flooding having lasted about 

 forty-two hours and both days having been clear. The night of June 13 

 was cold, the temperature at near-by bogs falling to 33° F. The water on 

 the upper bog was held until the night of June 14, the flooding period being 

 about seventy-two hours. 



These bogs were examined a few days later. Most of the buds on the 

 two lower ones showed a peculiar injury, their tips having turned dark 

 red or blackish and having opened somewhat. In this condition they had 



1 Van't Hofi: Studies in Chemical Dynamics, trans, by Ewan, 1896, p. 126. Kuijper: Rec. 

 Trav. Bot. N^erl., 7; 131-239, 1910. Gore: U. S. Dept. Agr., Bur. of Chem., Bui. No. 142, 1911, 

 pp. 5-28. 



2 Matthaei; Phil. Trans. Roy. Soc, B, 197: 47-105, 1905. 



' As might be expected, for the pistil respires faster than any other part of the flower. Maige: 

 Ann. Sci. Nat., Bot., Ser. 9, 14: 1-62, 1911. 



