Published online by Cambridge University Press: 20 January 2017
Modification of the cropping environment to make weed seed more susceptibleto fatal germination or decay processes is based, in part, on the premisethat seed longevity is affected by the crop-influenced environment in whichseed is produced, hereafter, called the maternal crop environment. The objective of this investigation was todetermine the influence of maternal crop environment on wild-proso milletseed production, germinability, and seed coat tone (i.e., lightness), atrait previously associated with seed longevity in wild-proso millet.Maternal corn environments were established by growing wild-proso milletplants in four morphologically different sweet corn hybrids in fourreplicates over 2 yr. Wild-proso millet seed was collected at sweet cornharvest, enumerated, characterized for seed coat tone, and tested forgermination. Principal component factor analysis reduced six sweet corntraits measured between silking and harvest into a single maternal cornenvironment factor that accounted for 84% of the variation among cropcanopies. Functional relationships between maternal corn environment factorscores and wild-proso millet seed characteristics were clarified by fittinglinear models. For each unit decrease in maternal environment factor score,wild-proso millet seed production increased 1,535 seed m−2,germination increased 2.2%, and seed coat tone was 1.8% lighter. Theseresults show the size and germinability of wild-proso millet seed washighest in less-competitive maternal corn environments characterized by ashort time to crop maturity and a small crop-canopy size.