CHLORSULFURON INFLUENCE ON GARDEN PEA REPRODUCTION

The influence of chlorsulfuron on the reproduction of green pea (Pisum sativum) was examined by exposing plants at 3 different stages of dev elopment to 3 different exposure levels (46, 92, and 180 mg ha(-1); co rresponding to 2 x 10(-3), 4 x 10(-3), and 8 x 10(-3) of the recommend ed field application rates for small grain crops). Reproduction was on ly influenced by the two higher rates. The most susceptible stage of d evelopment was when plants possessed 6 expanded leaves and one visible flower bud. At that stage, an application rate of 180 mg ha(-1) (0.8% of the recommended field rate) reduced the seed yield of treated plan ts to 1% of that of the control plants without severely altering the h eight or appearance of mature plants. When correspondingly low applica tion rates of atrazine, glyphosate, and 2,4-D were administered at thi s same developmental stage there were no effects on either growth or r eproduction. Thus, chlorsulfuron had an influence on plant reproductio n that was not produced by other herbicides administered at low levels .