Corn is a vital global crop, yet its cultivation demands extensive agrochemical inputs, prompting the need for sustainable alternatives. This study investigates the impact of vermicompost (VC) and vermicompost tea (VCT) applications on corn growth, physiology, and resistance to Fall Armyworm (FAW) infestation using advanced optical plant sensors. Six treatments were employed: V0 (control), VC1, VCT100, VC1 + VCT50, VC3, and VC3 + VCT50. During the growing season, plant growth parameters, such as height, chlorophyll content, and spectral reflectance were measured using a chlorophyll meter, fluorometer, porometer, and spectroradiometer. Results indicated that VC-treated plants exhibited superior growth and higher chlorophyll content than control or untreated plants. The VC1 + VCT50-treated plants showed robust resistance to FAW, with no infestation throughout the season, while VC1-treated plants showed delayed attack by FAW. Soil chemical analysis showed that VC and VCT treatments had similar nutrient concentrations as the control. Plant nutrient content was higher in VCT100 compared to all treatments. These findings suggest that the combined application of VC and VCT, particularly at specific application rates, can enhance corn plant health, mitigate pest damage, and optimize yield potential.