ENHANCING CROP SAFETY IN INTERCROPPING SYSTEMS WITH Celosia argentea THROUGH SAWDUST TREATMENT OF ATRAZINE AND NICOSULFURON RESIDUES

Atrazine and nicosulfuron are persistent herbicides widely used for weed management in maize. The persistence of these herbicides prolongs weed control but may cause injury to maize intercrops and subsequent crops planted after maize. Hence, soil amelioration may be necessary to mitigate the phytotoxic effects of herbicide residues on these crops. A screenhouse experiment was conducted to investigate the effect of sawdust on atrazine and nicosulfuron residues in the soil using Celosia argentea as a test crop. Treatments consisted of factorial combinations of four levels of herbicide (herbicide-free (control), atrazine at 3.0kg a.i ha⁻¹, nicosulfuron at 40 g a.i ha⁻¹, and a mixture of atrazine and nicosulfuron at 750 g a.i ha⁻¹ and 60 g a.i ha⁻¹) and five levels of sawdust by volume (0% (control), 5%, 10%, 15%, and 20%). These were laid out in a completely randomised design with four replications. Findings indicated that residues of the herbicide levels in the soil did not significantly (p≥0.05) reduce the number of leaves, plant height, and fresh weight of Celosia. However, nicosulfuron negatively impacted the dry weight of Celosia shoots. Sawdust at a low proportion of 5% and 10% improved Celosia growth, whereas a 20% proportion reduced Celosia growth. The interaction of atrazine and nicosulfuron with 5% sawdust resulted in enhanced growth and yield of Celosia compared to untreated soil. Hence, for follow-up crops of maize, addition of 5% sawdust is recommended within the rooting depth of atrazine and nicosulfuron-treated soil.