THE USE OF WHOLE PLANT CHAMBERS TO DETERMINE THRESHOLD FOR MITES IN SOUR CHERRY
The effects of mite damage to 'Montmorency' sour cherry trees were examined at the Northwest Horticultural Experiment Station in Traverse City, MI USA. The experiment was organized in a randomized complete block design with four blocks and four treatments. The treatments were assigned by the number of bags of mite infested bean plants that were placed in each tree and were designated control, low, medium, and high (0, 3, 6, and 12 bags). The trees were monitored for mite damage and subsequent photosynthesis at three dates during the growing season. Mites were brushed from leaf samples and counted to determine mites per leaf. Mite days were calculated by multiplying days by mites per leaf. Single leaf photosynthesis, chlorophyll fluorescence, and whole plant photosynthesis was determined on selected trees throughout the growing season. Results showed increased mite levels over the season starting at zero in June, reaching a peak in August, and receding in September. Single leaf photosynthesis measurements showed declines in the uptake of carbon dioxide with increasing mite-days. Whole plant photosynthesis measurements had the same trend as single leaf determinations. No correlation was found between the level of mite infestation and the yield of cherries.
Breitkreutz, S., Flore, J., Hubbard, M. and Johnson, J. (1997). THE USE OF WHOLE PLANT CHAMBERS TO DETERMINE THRESHOLD FOR MITES IN SOUR CHERRY. Acta Hortic. 451, 369-374