Flowering Patterns, Seed Production, and Somatic Polymorphism of Three Weed Species

Abstract

Field studies determined flowering pattern, seed production, and somatic polymorphism of pitted morningglory, common cocklebur, and sicklepod under interspecific and no interference with soybean. Flowering patterns differed between years but were similar under both interferences. Interspecific interference reduced flower and seed numbers 85 to 99%. Rainfall had little effect on flowering, but photoperiod and temperature responses were evident for all weed species. The production equations for seed number per plant from dry weight were quadratic for pitted morningglory and common cocklebur but linear for sicklepod. All species showed somatic polymorphism; however, differences in seed germination and viability were not consistent between years.