Controlling Armyworm (Spodoptera exigua) (Lepidoptera: Noctuidae) on Shallot using Nano Husk Ash

Abstract

Abstract The Beet Armyworm (Spodoptera exigua) is a polyphagous defoliator that poses a significant threat to cultivated plants, particularly shallot crops. Its attacks during the vegetative phase cause substantial damage. To control this pest, farmers often resort to synthetic pesticides, leading to negative consequences such as resistance development. To address consequences, internal control measures, like enhancing plant resistance through beneficial nutrients like silica, are crucial. Silica has been known to improve plant resistance against pest attacks. This study aims to investigate the effects of various methods of applying nano-sized rice husk ash fertilizer on the growth and resistance of Biru Lancor cultivar of shallots against S. exigua. Nano-rice husk ash fertilizer with an average particle size of 65,326 nm was produced and applied using three methods: placement, foliar, and seed coating. The results demonstrated that all methods of nano-rice husk ash application increased plant resistance, reducing leaf damage and pest mortality. The foliar application yielded the best results, enhancing plant height and epidermal cell wall thickness. Furthermore, nano-rice husk ash application positively influenced shallot productivity. This study highlights the potential of nano-sized rice husk ash as a sustainable and effective internal control measure against S. exigua, complementing synthetic pesticides for shallot pest management.