Improving flavor in the veggies and fruits we grow is a continuing focus for virtually every grower. With hydroponic growing, more factors are controllable by the grower and therefore the opportunity to discover methods during the growing cycle that help to accomplish better flavor is available and sought after.
There are many published articles discussing the regulation of crop nutrients to adjust and improve flavor and plant tissue chemical content. There are, however, other aspects that have major roles in taste and nutrition.
Photosynthesis is a primary operation within a plant and is responsible for a major role in crop taste. The light that we provide our crop is the number-one driver in powering photosynthesis and is very worthy of our attention in this matter.
First, reviewing the different types of lighting available becomes necessary when discussing photosynthesis:
- Incandescent light bulbs using reflectors have traditionally been used to create artificially long days. This type of light does have a wide range of light spectrum but is generally low in blue light, which is at the higher end of the photosynthetically active radiation (PAR) light range. Blue light is important to plants in several different areas. Another drawback to incandescent is that it produces a high amount of heat energy. In a cold climate greenhouse, this heat can be beneficial, but it isn’t typically wanted in other situations.
- Compact fluorescent lights are more efficient in producing blue and red light spectra, but are not generally good at far red light, which is important for stimulating certain plants’ flowering. Tube-type fluorescent bulbs are physically large but do offer a variety of benefits for the grower to consider. High intensity discharge lamps (metal halide and high pressure sodium) are great for providing much higher levels of light to boost photosynthesis and growth. Boosting photosynthesis during key periods of the growth cycle can provide various other benefits beyond just extra growth (see below).
- Light emitting diode (LED) lighting devices are very energy efficient and can allow the provision of greatly increased light energy without the concurrent addition of higher ambient temperature. Light spectrum availability with LEDs is also easily adjustable. These lighting units can work very well with a system applying the benefits of photoperiodism.