Nutrient Solution Management System for Smart Farms and Plant Factory

Perilla frutescens (Lamiaceae) is a dietary staple in Asia. It is an abundant source of flavonoids that are bioactively beneficial to human health and fitness. The current popularity of plant-based consumption is being driven by the healthful benefits of bioactive nutrition, and the concentration of bioactive agents found in raw plant materials is an important factor in the assessment of food quality. To test the feasibility of promoting flavonoid productivity in perilla plants via environmental treatment, plant factory technology was applied to perilla plant cultivation. Apigenin (AG) and luteolin (LT) are two of the most potent anticarcinogenic flavonoids in perilla, and these are also found in many vegetables and fruits. Quantitative analysis of AG and LT was conducted on plants cultivated under nine environmental forms of treatment imposed by three levels of light intensity (100, 200, and 300 µmol·m−2·s−1) combined with three levels of nutrient-solution concentration (1.0, 2.0, and 3.0 dS·m−1) for hydroculture. The contents of AG in green and red perilla plant were increased by high nutrient-solution levels under the same light intensity. In green perilla, the highest concentration of AG (8.50 µg·g−1) was obtained under treatment of the highest level of nutrient-solution (3.0 dS·m−1) and 200 µmol·m−2·s−1 of light intensity, whereas in red perilla, the highest concentration of AG (6.38 µg·g−1) was achieved from the highest levels of both of these forms of treatment (300 µmol·m−2·s−1 and 3.0 dS·m−1). The increase in AG content per plant between the lowest and the highest levels was recorded by 6.4-fold and 8.6-fold in green and red perilla, respectively. The behavior of LT concentration differed between green and red forms of perilla. LT concentration in red perilla was enhanced under nutrient deficiency (1.0 dS·m−1) and affected by light intensity. Different responses were observed in the accumulations of AG and LT in red and green perilla during treatments, and this phenomenon was discussed in terms of biosynthetic pathways that involve the expressions of phenylpropanoids and anthocyanins. The total yield of flavonoids (AG and LT) was improved with the optimization of those forms of treatment, with the best total yields: 33.9 mg·plant−1 in green Perilla; 10.0 mg·plant−1 in red perilla, and a 4.9-fold and a 5.4-fold increase was recorded in green and red perilla, respectively. This study revealed that flavone biosynthesis and accumulation in perilla plants could be optimized via environmental control technologies, and this approach could be applicable to leafy vegetables with bioactive nutrition to produce a stable industrial supply of high flavonoid content.

Download Full-text

Nutrient Uptake of Single-node Cutting Rose `Red Velvet' and `Vital' by Nutritional Control in a Plant Factory

HortScience ◽

10.21273/hortsci.39.4.769a ◽

2004 ◽

Vol 39 (4) ◽

pp. 769A-769

Author(s):

Kyung-Hwan Yeo* ◽

Jung-Min Son ◽

Yong-Beom Lee

Keyword(s):

Control System ◽

Nutrient Uptake ◽

Nutrient Solution ◽

Root Zone ◽

Drainage Water ◽

Ionic Ratio ◽

Single Node ◽

Target Values ◽

Plant Factory ◽

Plant Stage

The plant factory to control growing system automatically is necessary to cultivate single-node cutting rose, which produce large numbers of uniform shoots per unit area in short cultivation. However, the recirculation of the nutrient solution in closed system leads to several problems. One of them is connected with the quality of nutrient solution and the supply of minerals. The uptake of specific nutrients depends on growth and development, or plant stage, which results in a shift in ionic ratio in the drainage water compared to the nutrient solution supplied. Consequently, the nutrient supply should be controlled to be equal to the demand of the plant to avoid disorder of nutrient solution, such as depletion or accumulation. Therefore this study was conducted to examine the effect of mineral nutritional control on nutrient uptake of single-node cutting rose `Red velvet' and `Vital' in a plant factory. The nutritional control of nutrient solution was conducted by five methods: the control of electrical conductivity (EC), N, P, and K elements (NPK), macro elements (M), macro and micro elements (MM) to target ranges in root zone, and the supplement of nutrient solution (S). In NPK, M, and MM control system, the input of nutrients was calculated as amounts of absorption by the plants compared to target values in root environment. The fertilizer supplement of N, P, and K was lower in EC control system than other control systems. In EC and S control system, the concentration of NO3- -N and K in root zone exceed optimal range whereas P, Ca, and Mg decreased at the later stage of growth. The concentrations of each nutrient in root environment were kept at the target ranges in M and MM control system, which showed optimum yield and product quality.

Download Full-text