Allelopathic effects of dryland plant extracts on the sprouting of purple nutsedge (Cyperus rotundus L.)

This study explores the potential of ten arid dryland plant species as novel bioherbicides for the sustainable suppression of purple nutsedge (Cyperus rotundus L.), a troublesome weed in many ecosystems. We investigated the allelopathic effects of Calotropis procera, Alhagi maurorum, Tamarix aphylla, Aerva javanica, Capparis decidua, Withania coagulans, Leptadenia pyrotechnica, Haloxylon salicornicum, Fagonia indica, and Rhazya stricta using a factorial experiment arranged in a completely randomized design with four replications. Three treatments were compared: a control (C1), a crude aqueous extract (C2), and a 20-fold concentrated extract (C3). The concentrated extracts (C3) of all species completely inhibited the sprouting and growth of purple nutsedge. Notably, F. indica (P9 × C2) achieved 100% suppression even at the crude extract level, performing comparably to the concentrated extracts of the other species. H. salicornicum (P8 × C2) and L. pyrotechnica (P7 × C2) showed statistically similar suppression to F. indica. Other crude extracts significantly reduced sprouting percentage, sprouting energy, vigor index, shoot and root length, biomass, and chlorophyll index compared to the control, except for A. maurorum and W. coagulans. These findings underscore the potential of dryland plant extracts, especially F. indica, as promising natural herbicide sources for managing purple nutsedge. Incorporating these bioherbicides into integrated weed management strategies offers a sustainable and eco-friendly alternative to synthetic herbicides, reducing their usage and enhancing ecological health.