Effect of Fertilization Combined with Shading on Growth and Aromatic Constituents of Niamhom (Strobilanthes nivea Craib) Using an Internet of Things (IoT) Controlled Irrigation System

The Niamhom (Strobilanthes nivea Craib) plant was cultivated using a modern greenhouse with an automatic irrigation system controlled by the Internet of Things (IoT). The present study investigates the effects of fertilizers, including chemicals, cow manure fertilizer, and bio-fermented water with shading influences of 50 and 70% on plant growth and morphological characteristics. Additionally, the study aims to analyze the chemical constituents of cultivated Niamhom leaf evaluated by Gas Chromatography-Mass Spectrometry (GC-MS). Findings discovered that 50 and 70% shading did not affect plant stem size and canopy diameter. However, shading at 50% affects chlorophyll content, yield, dry weight, leaf diameter, plant height, and the number of leaves. There were no differences in plant growth parameters among the three fertilizer treatments, but significant differences were found in leaf number, leaf area, and chlorophyll content. The chemical fertilizers gave the highest values, followed by cow manure fertilizer and bio-fermented water. The leaves of the Niamhom plant grown in 70% shade with cow manure fertilizer application had the highest overall aromatic content, followed by plants grown in 50% shade with cow manure and chemical fertilizers, respectively. However, when the synergistic interaction of fertilizers and shade factor of 50 to 70% were examined, it was revealed that the chemical odorants of the Niamhom leaf interacted significantly. The whole aromatic substances were detectable in dichloromethane (DCM) extracts, except 2-hexanal in ethyl acetate mediated extract. GC-MS analysis revealed that the primary substances in Niamhom leave comprised 2-propionyl-3,4,5,6-tetrahydropyridine, 2-propionyl-1,4,5,6-tetrahydropyridine, hexanoic acid, 3,5,5-trimethyl-, nonyl ester, n-hexadecanoic acid, phytol, 9,12-octadecadienoic acid. The specific aroma compounds of Niamhom leaves that can be utilized as indicators for the herb’s potential consist of 2-hexenal, 2-acetyl-3,4,5,6-tetrahydropyridine, maltol, 2-acetyl-1,4,5,6-tetrahydropyridine, hexanoic acid, and 3,5,5-trimethyl-, nonyl ester. Future surveys are necessary to be performed for Niamhom as a potential herb plant for aromatic and several food applications.