Notes: Effects of Shaking and Shading on Growth of Three Hardwood Species

Manual shaking of greenhouse-grown black walnut, sweetgum, and silver maple seedlings daily for 30 seconds reduced height growth within a few days after shaking treatments were started. With the exception of black walnut, stem diameter, dry weight accumulation, and leaf area during a 50- to 60-day period were not significantly affected, which suggests strongly that shaking primarily affects endogenous processes rather than directly affecting photosynthesis. Heavy shading reduced all aspects of the growth of the seedlings, but in most cases did not alter the responses to the shaking treatments. Forest Sci. 25:212-216.