Author(s)

Junias Sogra¹, Lux Jimmy^2,3, Kenndy Kamik⁴, Alex Galus^4*

¹Department of Agriculture, Papua New Guinea University of Technology, Lae, Papua New Guinea.
²Department of Agriculture, Sonoma Adventist College, Kokopo, Papua New Guinea.
³Coconut Product Limited, Rabaul, Papua New Guinea.
⁴National Agricultural Research Institute, Kokopo, Papua New Guinea.

Maize is widely cultivated in Papua New Guinea (PNG) and provides farmers with nutrition and income. However, the fall armyworm (FAW) (Spodoptera frugiperda) (J.E. Smith) (Lepidoptera: Noctuidae) invasion is a threat to its production and supply. Hence, this field experiment was conducted to assess the bio-efficacy of plant-derived pesticides (PDPs) against FAW and their interactive effects on maize agronomic performance under field conditions. The treatments studied were turmeric rhizome extract (TRE), neem leaf ash solution (NLAS), neem bark extract (NBE), and untreated plots (control) and were replicated 5 times using the randomized complete block design. The data were subjected to analysis of variance and means were separated by Fisher’s protected least significant difference test. The result showed that the application of PDPs significantly reduced FAW infestation during the period of peak infestation. At 33 DAS, NBE significantly had the lowest number of FAW larvae (0.6) [F (4, 15) = 5.11, p = 0.02] and FAW attack intensity (29.8%) [F (4, 15) = 8.69, p < 0.001] compared to the control. Apart from the control, it also had the lowest FAW attack intensity (0 %) [F (4, 15) = 3.58, p = 0.04] and had the highest number of harvested ears (5.0) [F (4, 15) = 3.72, p = 0.04] and fresh ear weights (447 g) [F (4, 15) = 4.65, p = 0.02] compared to NLAS. The TRE and NLAS had performed poorly relative to the control. Hence, NBE can be used to control FAW infestation at a period of high attack intensity (33 DAS). Moreover, this study will provide basic information for future studies on biopesticidal plant extracts as a control of FAW infestation under field conditions in PNG.

FAW Larvae, Attack Intensity, Plant Height, Harvested Ear, Ear Fresh Weight

Sogra, J. , Jimmy, L. , Kamik, K. and Galus, A. (2023) Bio-Efficacy of Plant-Derived Pesticides against Fall Armyworm (Spodoptera frugiperda) and Their Interactive Effects on Maize Agronomic Performance under Field Conditions. Agricultural Sciences, 14, 1535-1546. doi: 10.4236/as.2023.1411099.