Abiotic Factors Affecting Seed Germination and Early Seedling Emergence of Large Crabgrass (Digitaria sanguinalis)

Abstract

Large crabgrass is one of the worst exotic weed in tropical, subtropical, and temperate regions of the world. In this study, the abiotic factors affecting seed germination and early seedling emergence of large crabgrass were investigated under laboratory conditions. The optimum temperatures of germination occurred at the range from 25 to 35 oC under 12 h light/12 h dark condition. Some seeds could germinate in the dark, but light exposure significantly stimulated the germination. Large crabgrass seed was tolerant to salinity level range of 0 to 160 and low water potential (11% germination at -0.8 MPa). Medium pH had no significant effect on seed germination and more than 90% seeds germination was obtained over a broad pH range from 4.0 to 10.0. Seed germination was significantly influenced by heat-shock and completely inhibited at 140 oC for 5 min. The greatest seedling emergence rate was 96% when seeds were planted at a soil depth of 1 cm. Knowledge of germination biology obtained from this study will be useful in the development of the integrated weed management strategies for this species, and to avoid its establishment as a troublesome weed in economically important cropping regions.

Effect of Crop Residues on Weed Emergence

“…A. theophrasti emergence was delayed in both years from one to several weeks with the increasing amount of residues, and similar results were observed in the emergence patterns of E. crusgalli with emergence delay of few weeks up to a month, with the increasing amount of residues. These results are probably the product of the interaction between the specific microclimatic conditions created by the residues and the biology of these species that have different requirements of light, moisture, and temperature for dormancy breaking and germination [38][39][40][41][42][43]. However, we can comment on these results only hypothetically, considering that no measurements of microclimatic conditions underneath the residues were conducted, as it was not the goal of this work.…”

Germinação de sementes de Amaranthus deflexus L. submetidas a diferentes condições de tempera-tura e estresse salino

“…For the species Senna multijuga, the temperatures of 30 ºC (constant) and 20-30 ºC (alternating) resulted in the highest germination percentage (Ribeiro et al, 2016). Wang et al (2017) reported that the best temperatures for germination in the species Digitaria sanguinalis were between 25 and 35 ºC. Wenneck et al (2021) subjected Amaranthus viridis seeds to accelerated aging at a constant temperature of 42 °C and obtained a reduced germination potential of the seeds compared with those that were not subjected to this treatment.…”