Intercropping of Sweet Corn (Zea mays L. var. saccharata) and Turmeric (Curcuma longa L.) for the Management of Fall Armyworm, Spodoptera frugiperda (J. E. Smith) and its Economic Feasibility

This study evaluated the ecological, agronomic, and economic effectiveness of intercropping sweet corn (Zea mays L. var. saccharata) with turmeric (Curcuma longa L.) against monoculture sweet corn for the management of the fall armyworm, Spodoptera frugiperda (J. E. Smith), and enhancement of land productivity. The experiment was conducted over two successive sweet corn cropping cycles and one turmeric cycle in Indonesia. The results varied temporally: the first cropping cycle showed no significant effect on vegetative pest infestation or damage. However, in the second cycle, the established intercropping system significantly reduced the percentage of infested plants, leaf damage intensity, and larval populations of S. frugiperda. Crucially, ear infestation was significantly lower in the intercropping plots during both cycles. Agronomically, reduced pest pressure led to significantly higher sweet corn cob weight in the second cycle under intercropping than under monoculture. Economically, the intercropping system demonstrated superior financial viability, yielding nearly six times higher net profit. This profitability was confirmed by strong metrics: Revenue/Cost (R/C), Benefit/Cost (B/C), and Return on Investment (ROI) ratios of 2.50, 1.502, and 150.2%, respectively, all exceeding monocultures. The lower break-even point with intercropping also indicated superior land-use efficiency. These overall findings suggest that the sweet corn–turmeric intercropping system is a sustainable, profitable, and ecologically sound strategy for S. frugiperda management and improving agricultural resilience.