Modification of the cropping environment to make weed seed more susceptible
to fatal germination or decay processes is based, in part, on the premise
that seed longevity is affected by the crop-influenced environment in which
seed is produced, hereafter, called the maternal crop
environment. The objective of this investigation was to
determine the influence of maternal crop environment on wild-proso millet
seed production, germinability, and seed coat tone (i.e., lightness), a
trait previously associated with seed longevity in wild-proso millet.
Maternal corn environments were established by growing wild-proso millet
plants in four morphologically different sweet corn hybrids in four
replicates over 2 yr. Wild-proso millet seed was collected at sweet corn
harvest, enumerated, characterized for seed coat tone, and tested for
germination. Principal component factor analysis reduced six sweet corn
traits measured between silking and harvest into a single maternal corn
environment factor that accounted for 84% of the variation among crop
canopies. Functional relationships between maternal corn environment factor
scores and wild-proso millet seed characteristics were clarified by fitting
linear 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. These
results show the size and germinability of wild-proso millet seed was
highest in less-competitive maternal corn environments characterized by a
short time to crop maturity and a small crop-canopy size.