Ｑ What is a plant factory?
A plant factory is a system and facilities to automatically and continuously produce vegetables, seedlings and other crops regardless of the season by artificially controlling ambient conditions such as light, temperature, humidity, CO2 concentration and culture solution. Plant factories can be categorized into sunlight-based factories and totally-controlled factories. In most factories, hydroponic farming is conducted because it is very easily controlled. Totally-controlled plant factories are the only system that can grow all kinds of crops without using any agricultural chemicals.
Ｑ What kind of light sources do you use to grow plants?
High-pressure sodium lamps, metal halide lamps, fluorescent lamps and LEDs, etc., have been used as artificial light sources in totally-controlled plant factories. Until several years ago, high-pressure sodium lamps were mainly used because of their high luminous efficiency. Recently, fluorescent lamps and LEDs are attracting a lot of attention because the light they emit radiates less heat, making them suitable for multistage cultivation. Meanwhile, high-pressure sodium lamps are frequently used as supplemental light in sunlight-based plant factories.
Ｑ What are the challenges that plant factories face?
The basic challenge is to reduce costs in various areas. In particular, it is important that overall production be inexpensive in order to reduce service costs. In order to differentiate products by enhancing their functionality, new cultivation techniques to grow delicious and highly nutritious vegetables will be required as important technologies in the future. For the promotion of plant factories, it is also important to study how they should be modularized and standardized.
