Effects of plant-derived smoke on the growth dynamics of Barnyard Grass (Echinochloa crus-galli)

The stimulation of seed germination by smoke and aqueous smoke extracts from the combustion of plant material has recently received a great deal of attention. This study was conducted to assess the effects of smoke on the weed species Echinochloa crus-galli (barnyard grass). Plant-derived smoke was produced from Bauhinia variegata using a newly designed furnace and then applied to the weed species. The results showed that plant-derived smoke solution significantly increased the germination rate (70-92.3%), germination percentage (31-47%), fresh weight (30-69%), shoot and root length (10-14.9%, 35-44%), germination index (50-100%) and vigour index (114-157%) of barnyard grass relative to the control. Treatment with plant-derived smoke solution also significantly reduced the endogenous abscisic acid of seeds, while α-amylase activity increased significantly compared to the control. Overall, these findings indicate that stimulation and quick emergence from a dormant soil seed bank of barnyard grass can be induced by plant-derived smoke solution followed by chemical control through known weedicide/herbicide treatments as an eco-friendly alternative method of weed control.