EFFECTS OF COPPER-SULFATE ON BLACK BINDWEED (POLYGONUM-CONVOLVULUS L)

Seedlings of black bindweed (Polygonum convolvulus L.) were transplant ed to soil contaminated with copper sulfate at different dosages. Thes e plants were followed until maturity under greenhouse conditions, and measures of mortality, growth, and reproduction were obtained from ha rvests 21, 34, and 105 days after the transplant. It was found that ap plication of 125 mg Cu2+ kg(-1) resulted in 1.7% lifetime mortality in creasing to 100% at 500 mg kg(-1). The mortality was dependent on expo sure time. No further mortality was observed after 50 days. The popula tion consisted of a relatively tolerant and a sensitive group. This wa s indicated by differences in lifetime of plants treated with 500 mg k g(-1) and by a diversification in biomass of individuals dying from tr eatment with 315 mg kg(-1). The plants surviving treatment had reduced biomass and seed production at dosages above 200 mg kg(-1). (C) 1996 Academic Press, Inc.