Variation among black walnut seedling families in resistance to competition and allelopathy

Summary Of three environmental variables affecting black walnut seedling establishment, moisture stress overshadowed the effects of fescue leachate and fertilizer. Interactions between moisture stress and family and between fescue leachate and moisture stress for both seedling height and dry weight suggested that selection for tolerance to moisture stress is possible, whereas progress from selecting for resistance to rescue leachate would be difficult. Family response to high moisture stress resulted in reductions of 17 to 33 percent in height and 36 to 48 percent in dry weight when compared with seedlings grown under moist conditions. The only effect of fertilization was a 9 percent decrease in seedling survival under high moisture stress conditions