Field Efficacy of Aqueous Root Extract of Securidaca longipedunculata Fresen for the Management of Fall Armyworm (Spodoptera frugiperda J.E. Smith) in Maize in Northern Ghana

Maize growers across Sub-Saharan Africa incur significant yield losses due to fall armyworm (FAW), Spodoptera frugiperda, infestations and damage. Reliance on synthetic insecticides poses environmental and health risks, driving the need for eco-friendly botanical alternatives. Here, the efficacy of crude Securidaca longepedunculata aqueous root extracts in mitigating FAW infestations and damage, as well as its effect on grain yield, was studied over two successive seasons in maize. Treatments comprised three rates of S. longipedunculata root extracts (i.e., 3.13% w/v, 6.25% w/v, and 9.38% w/v), together with untreated control, neem oil as a botanical control, and Emastar 112 EC (a.i.: emamectin benzoate 48 g/L + acetamiprid 64 g/L) as a synthetic insecticide control. Data on FAW larval infestation, leaf and cob damage, as well as grain yield, were analyzed. The results showed that infestations and damage were highest in the untreated control plots. Conversely, infestation and damage were lowest in Emastar 112 EC treated plots. Notably, application of 6.25% w/v and 9.38% w/v S. longepedunculata extracts significantly reduced FAW infestations and damage compared to the untreated control, though their efficacy was lower than that of Emastar 112 EC. Grain yield was highest in Emastar 112 EC treated maize, while the untreated control was lowest. Extracts of S. longepedunculata applied at 6.25% w/v and 9.38% w/v outperformed the untreated control and the neem oil check. These findings indicate that while synthetic insecticides remain the most effective option, aqueous extracts of S. longepedunculata at rates ≥ 6.25% w/v offer a potent, accessible, and sustainable alternative for smallholder farmers to protect maize yields.