SEED PRODUCTION AND SEED WEIGHT OF 6 WEED SPECIES TREATED WITH MCPA

Four doses of MCPA (ranging from 1/8 to 1/1 of full dose) were applied close to the beginning of the generative phase in six annual weed species. Effects on seed production and seed weight were studied in a pot experiment. The herbicide caused large reductions in the seed production in Bilderdykia convolvulus (L.) Dumort, Chenopodium album L., Myosotis arvensis (L.) Hill and Thlaspi arvense L. but had no significant effect in Chamomilla recutita (L.) Rauschert and Galium spurium L. Treated plants of C. album (1/4 dose) and T. arvense (1/8 dose) produced fewer seeds per g shoot dry weight (seeds excluded) than the controls. The only effect that the herbicide had on the 1000-seed-weight was a slight increase in M. arvensis.