Abstract
We analyzed the release pathway, behavior in the environments, and species-specificity of the growth inhibitors that Solidago altissima released into the surroundings, in order to assess possible application of their allelopathic potential to weed control. Release of growth inhibitors neither from intact leaves through volatilization nor from living roots through exudation was detected. In contrast, release from dead leaves through leaching was evident. Various crops and weeds exihibited different sensitivities to leachate derived from S.altissima dead leaves. When applied to natural soil, effectiveness of growth-inhibirory activity of the S.altissima dead leaf leachate was lowered, suggesting absorption and/or degradation of the growth inhibitors under natural conditions. When fragments of air-dried and air-dried/water-extracted S.altissima aerial parts were used as mulch in field tests, weed emergence was more effectively reduced in the former case, suggesting that growth inhibitors released from the S.altissima mulch contributed to weed suppression.
