Weed seeds ability to emerge on the soil surface
Abstract
Annual weeds have to produce seeds each year to maintain their populations. These seeds fall
on the soil surface. Seeds exposed to light during their moistening (i.e. caused by rain) better
germinate than seeds in the darkness (i.e. buried). However, rare studies quantified the unique and
combined effects of light, moisture and burial depth on the germination process. We investigated,
in a greenhouse experiment in 2014, the impact of seed moisture (Moistened vs. Dried), light
during moistening (Darkness vs. Light) and burial depth (Buried vs. Surface) on germination of 12
annual weed species contrasted on their seed traits and germination periods (Alopecurus
myosuroides Huds., Amaranthus retroflexus L., Avena fatua L., Bromus sterilis L., Capsella bursapastoris
(L.) Medik., Cyanus segetum L., Chenopodium album L., Geranium dissectum L., Poa
annua L., Sonchus asper (L.) Hill, Veronica persica Poir., Vulpia myuros (L.) C.C.GME L.). Six
modalities were tested (with 5 replicates): MDS (moistened seeds in darkness and then placed on
the soil surface), MLS (moistened in light and placed on the surface), DLS (dried in light and
placed on the surface), MDB (moistened in darkness and then 0.5 cm-buried), MLB (moistened in
light and 0.5 cm-buried), DLB (dried in light and 0.5 cm-buried). Datasets were analysed with
generalized linear model (GLM, binomial distribution).