Abstract Alligatorweed, an invasive aquatic weed, has emerged as a major threat to sustainable crop production in various crop species. A two-year field study was conducted to investigate the impact of varied competition durations of alligatorweed on mungbean. The competition durations with alligatorweed included weed free conditions for first 3, 4, 5, 6 and 7 weeks after crop emergence along with a full season weed free treatment and alternatively weedy conditions for the aforementioned durations along with a full season weedy treatment. Competition with alligatorweed led to significant uptake of nitrogen (N), phosphorus (P) and potassium (K), with maximum uptake observed in the full season weedy treatment with N, P and K up to 65, 19, 56 kg ha -1 , respectively. Additionally, significant accumulation of heavy metals (HMs) including copper (Cu), iron (Fe), manganese (Mn), zinc (Zn) and arsenic (As) up to 20, 16, 30, 14 and 11 g ha -1 , respectively, was observed. Full season weedy plots produced more alligatorweed biomass and caused reductions of up to 81% in mungbean yield components. Alligatorweed infestation resulted in significant mungbean grain yield losses of up to 44% during 2022 and 52% in 2023, respectively. Furthermore, the three-parameter log-logistic equations identified the period from 4.2 to 6.8 weeks after crop emergence (WACE) as the critical period of alligatorweed competition that could result in a 10% yield loss in mungbean. Hence, alligatorweed poses a significant threat to mungbean production due to its strong competitive ability. However, its potential for HM accumulation offers promising opportunities for phytoremediation in both aquatic and terrestrial environments.
Abbas et al. (Tue,) studied this question.