Increasing mustard (Brassica juncea L.) yields through exposure sound and preventive pest management based on refugia plants

In Indonesia, mustard plants will increase by 8.2% in 2021, but more than that is needed to meet the community's needs due to a growing population. Pests and fertilization issues hinder the anticipated growth, but the application of sound can serve as an alternative to traditional plant fertilizers, as exposing plants to sound can enhance their growth by opening stomata, facilitating water absorption, and promoting increased nutrient uptake. This study aimed to examine the application of sound effects and refugia plants to increase the growth and yield of mustard greens (Brassica juncea L.). The study used a Time's Series Randomized Block Design with three replications, and significant data were analyzed using a different test at the 5% confidence level. The first factor is sound applications (S) consisting of S0 = without sound, S1 = rock music (Frequency 21-14,000 Hz), and S2 = classical sound (Frequency 21-14,000 Hz). The second factor is the refugia plant (R) consisting of R0 = without refugia, R1 = Tagetes erecta L., R2 = Zinnia elegans L, and R3 = Ocimum bassilicum L. The application of classical sound frequency (20-14,000 Hz) significantly affects the growth process of mustard plants, including plant height, leaf count, leaf area, and total chlorophyll. Refugia plants affect the process of plant protection through their ability to attract pests in the research area.