Herbicidal and allelopathic effects on seed germination and growth of annual ryegrass and celery plants

Abstract

In response to environmental concerns and human health, the global demand is focused on decreasing the use of synthetic herbicides and increasing the application of allelopathic plant extracts. This study aims to investigate the effects of various concentrations of herbicides (HC) (0, 1, 2, 3, and 4 mL/L) and laurel leaf extract (LLE) (0, 2.5, 5, 10, and 15%) on weed plants such as Lolium rigidum (LR) and vegetable crops such as celery. The results revealed that manipulating these concentrations significantly impacts the seed growth characteristics of both plants. Results indicated that applying HC significantly influenced all attributes in this study, recording the minimum value for LR plants among all treatments. However, using HC for celery seeds recorded the maximum values for seed germination, germination time of 50%, mean daily germination, and mean germination time. Moreover, the germination index, germination speed, and germination energy of celery seeds were stimulated by LLE. LLE allelopathic applications enhanced the coefficient of velocity for LR seeds. Comparing HC and LLE, HC has a greater effect, decreasing seed germination across all seed parameters. Additionally, when comparing doses between HC and LLE, all doses of HC inhibited seed LR to zero for all characteristics. Untreated celery seeds improved and significantly influenced priority attributes. This approach aims to reduce the environmental footprint of traditional herbicides, offering a more sustainable alternative for weed management and crop protection. It helps researchers and farmers explore other doses for allelopathic extraction and plant applications.