Cranberry production involves the use of flooding for several purposes during the growing season, including pest control, winter protection, and harvest. The effect of the dissolved oxygen concentration in floodwater on carbohydrate concentration of uprights and roots during flooding was investigated using potted `Stevens' cranberry (Vaccinium macrocarpon Ait.) vines. Pots were placed in large bins filled with water to simulate a spring pest control flood (called late water) over a 21-day period. Two treatments were applied: oxygenated and nonoxygenated (control). Uprights and roots were collected every 3 days and prepared for HPLC analysis to quantify nonstructural carbohydrate concentration. Soluble sugar (sucrose, glucose, and fructose) and starch concentration, as well as total nonstructural carbohydrate (TNSC) concentration, decreased over the 3-week period in uprights but not roots regardless of treatment. Interestingly, the sucrose, glucose, fructose, and starch concentrations of uprights in the oxygenated treatment were lower than those of uprights in the control treatment throughout the experiment. This research indicates that vines in flooded bogs demonstrate a net carbon loss, resulting in reduced carbohydrate concentration available for growth and fruit production.

ADDITIONAL INDEX WORDS. Vaccinium macrocarpon, respiration, temperature SUMMARY. American cranberry (Vaccinium macrocarpon) production sites are often fl ooded for pest control and crop harvest. However, little is known about how this practice affects vines. A survey was conducted in Massachusetts over a 3-year period to determine the effect of spring, fall, and winter fl oods on total nonstructural carbohydrate concentration (TNSC) of cranberry uprights of four cultivars. With a few exceptions, TNSC generally was unaffected or increased during the course of the 1-month "late water" fl ood held from mid-April to mid-May. The 48-hour "fl ash" fl ood, held in mid-to late May, generally had little effect on vine TNSC. Fall "harvest" fl oods, which ranged in duration from 3 to 27 days, often resulted in a decrease in TNSC, with greater decreases in TNSC occurring in early fall fl oods compared to late fall fl oods. Decreases in TNSC during the harvest fl ood were as great as 42%. "Winter" fl oods had little effect on TNSC. Path coeffi cient analysis indicated that fl ood duration, date of application, water temperature, and dissolved oxygen concentration all impacted vine TNSC during the fl ood, while fl oodwater depth had little effect. Water clarity (i.e., light penetration to the vines during the fl ood) also appeared to have little impact. Due to the frequent observation of TNSC decline during fall fl ooding, it is possible that yield potential of cranberry vines is reduced by current fl ooding practices.