Cuticular wax composition and anatomical features of Cyperus rotundus L. in relation to herbicide uptake and translocation

Cyperus rotundus is one of the sedges that is widely considered to be the world’s worst weed and its control is troublesome due to a variety of factors. The objective of this research was to analyze the chemical composition as well as its morphology on leaves. It is important to know the barrier for absorption and translocation of foliar applied chemicals to control this weed effectively. Microscopic and SEM analysis revealed a thick epicuticular layer on the adaxial surface and thin layer on the abaxial surface, heterogenous wax coverage. While, GC-MS profiling identified major chemical constituents including pyrans, fatty acids, sesquiterpenes and nitrogenous compounds. Wax content ranged from 72.62 to 103.92 µg cm-2. that contributed to the formation of a nearly impermeable membrane in leaves that aids stress tolerance and act as a transport barrier for foliar applied chemicals. Formulation of glyphosate with appropriate surfactants, particularly CTAB at higher ratios (1:2) of herbicide-to-surfactant, significantly improved translocation to primary, secondary and tertiary tubers. The findings highlight the critical role of cuticular wax composition in herbicide resistance and demonstrate the potential of adjuvant selection and usage for optimal herbicide delivery as well as development of more effective weed control measures against C. rotundus and similar perennial weed species.