insun Grow Lights conducted a grow lighting trial in T&G's tomato greenhouse in Reporoa to demonstrate and evaluate the effect of supplemental light use on a commercial tomato crop. Three LINEA 800 high bay light units were deployed above a specified row of plants, and operated on a set timing schedule. Following the trial, feedback received was as follows:

• The plants generated a truss which was more generative (truss development was shorter and claw like at flowering stage) than those plants under no lighting. This enables for better fruit quality and faster setting speed.
• Plant strength was higher than those without lights. Light on time length or plant density would need to be managed appropriately to avoid the plant becoming too strong (I.e. 4.2 plants/m2 instead of a standard summer density of 3.3 plants/m2).
• Lights need to have more irrigation due to extra photosynthesis.

Improvements to be made are:

• Light setup – place above the walking row and not the plan row. This allows more light to all the leaves on the plant.
• Light control – Can be established, I believe, through industry Scada systems but light levels should be adjusted based on glasshouse climate and existing sun (watts/m2) levels. This would enable better energy efficiency and better plant development. The lights need to be able to receive controls from scada systems.

Although these lights were not the optimal form factor for a tomato vine crop, the positive results indicate that even a highly productive commercial greenhouse producing large volumes of fruit has the potential to leverage supplemental LED lighting to further increase productivity.

Use of supplemental lighting to enhance the natural light from the sun creates a measurable uptick in growth, volume of produce, and quality of produce, as well as the potential for fruit to mature faster. These advantages carry through year-round operation as the lighting makes up for the lack of sun in the darker seasons, permitting operations to scale up to year-round production.

Deployment of lighting on a commercial scale requires careful consideration of lighting layout and appropriate form factor to control exactly where the light is directed, and integration with smart greenhouse control systems to maintain on-the-fly light intensity control.

insun Grow Lights work with commercial growers to develop bespoke lighting solutions best suited to their operations, and compatibility with control infrastructure.