Founded in 2015, Dayton Valley Aquaponics is a year-round aquaponic greenhouse designed to provide the northern Nevada area with consistently fresh, sustainable, local produce. They currently use their LumiGrow fixtures to light 20,000 square feet of greenhouse. Tomatoes are Dayton Valley’s bread and butter – 80% of the facility is dedicated to growing beefsteak and cherry tomatoes. The remaining 20% is used to grow a variety of leafy greens, peppers, microgreens, herbs, and edible flowers. The facility is powered by a combination of solar and sustainable wood biomass fuel made of recycled materials, which allows the facility to be petroleum resource-free and carbon neutral.
Abysmal light levels
Prior to installing supplemental lighting, Dayton Valley Aquaponics had decent production during their first winter. However, as the greenhouse glazing’s transmittance rate declined, light levels in the greenhouse dropped dramatically. They had very little fruit set, and their plants' growth was nowhere near what it should have been with the nutrients their system was supplying.
“The DLI was 4 or 5 [mol·m−2·d−1],” recalls Mark Warrell, Dayton Valley’s Head Grower, “On day 220, the plants looked like they were on day 100.”
Since continuing production through the winter is important to their business strategy, Dayton Valley began to investigate ways to improve light levels in their greenhouse. They decided that supplemental lighting made the most sense, but quickly eliminated traditional HPS lighting as an option. They needed their lighting to be energy efficient enough to run on the facility’s existing solar power and fit with Dayton Valley’s sustainability ethos. LumiGrow fit the bill.
“When you break it down, an LED light can just be an LED light – a bunch of diodes. The smart learning on the sensors and being able to control [the fixtures] and break it down zone by zone really pushed us over the edge on making the decision to go with LumiGrow,” says Mark, “CEA [Controlled Environment Agriculture] is all about control. Unless you can control and manipulate the light levels, what are you doing? You might as well be dirt farmers at that point.”
20% more fruit trusses
Dayton Valley Aquaponics installed 325 Pro 650e fixtures with smartPAR for Greenhouse wireless control system. The smartPAR Light Sensors were installed at a ratio of one sensor per 4 fixtures. This allows the fixtures to measure light levels inside the greenhouse in real time, and automatically adjust their intensity to meet the target DLI needed for optimal growth.
Dayton Valley’s tomatoes are thriving under the lights, which utilize the smartPAR Light Sensors to maintain a DLI of 45. Mark noticed that the fruit on the trusses set faster and the internodal spacing on the plants is tighter. The vines’ growth rate has also increased by 20%. They grow so quickly that the plants need to be lowered before their first harvest - by the time the fruit is ready to be harvested, the vines have 7 fruit truss sets. The unlit vines usually had 5 fruit truss sets. The quality of the fruit has increased as well – Mark has seen a 30% increase in Grade No.1 fruit, which fetches the highest prices.
“We’re now able to keep light levels at a constant rate; growth parameters don’t shift so drastically throughout the day,” explains Mark, “We saw a lot of cracking and splitting before [we added supplemental lighting]. The plants weren’t transpiring at the correct rate.”
His quarterly tests have also shown that his tomatoes’ brix levels, the percentage of solids present in the fruit’s juice, are 15% higher than unlit tomatoes of the same variety. Since these solids mostly consist of sugar and minerals, higher brix levels indicate better sugar-to-acid ratio and more nutrition.
Deeper leaf color and shorter turn times
In the greenhouse’s leafy greens zones, Mark aims for a DLI of 20 mol·m−2·d−1. This allows their red-leaf lettuce and red romaine to deepen in color, instead of remaining pale the way it did before the lights were installed. The first time they grew their lettuce under the LumiGrow lights, it only took one week for the leaves to color up. Mark has also been able to speed up his microgreens production time by 20%. Shrinking the tiny leaf green’s usual 10-day lifecycle down to 8 days has allowed Dayton Valley to squeeze in more turns of the high-value crop each year and increase their overall revenue.
Utilizing light for Integrated Pest Management
In addition to using a DLI program to maintain consistent light levels, Mark created a custom spectral program for integrated pest management (IPM). The program uses only blue light for an hour around sunrise and two hours around sunset to disrupt the lifecycle of soft-bodied insects such as aphids. When he sees significant pest pressure in his greenhouses, he supplements his tried-and-true DLI program with his IPM program. Within a couple weeks, the aphid pressure dispersed and soon became undetectable.
“The [smartPAR] app makes it easy to change [the program] on the fly,” Mark adds, “For example, if I get home and forgot to change it, all I have to do is pull out my phone.”
Aphid pressure is highest during the summer months. As a result, Mark continues to use his custom IPM light program year-round even when the sunlight exceeds his target DLI. Being able to use his lights instead of spraying chemicals or waiting for predator colonies to establish themselves brings both peace of mind and cost savings. Whenever the tables need to be sprayed, the entire greenhouse needs to be cleared. Each table requires at least 15 minutes to spray, and no one can enter the greenhouse for up to 12 hours, depending on which chemical was used. Stopping work in the entire greenhouse is detrimental to production and the company’s bottom line. Mark estimates that including his custom lighting program in his overall integrated pest management regime has reduced Dayton Valley’s spending by 5% for chemicals and over 10% for labor costs.
“The amount of chemicals you have to spray and the time it takes to do that stuff as opposed to just writing a program and [tapping a button] is paramount to success in both time savings and cost savings,” says Mark.
Long-term peace of mind
At the end of the day, Mark is glad that Dayton Valley Aquaponics chose to go with LumiGrow as their lighting provider, and is excited to continue to experiment with different spectral programs.
“The added bonus of the smartPAR system, controllability, and the spectral control is just awesome,” says Mark, “It really fits our business model as far as being innovative in the agricultural industry while being conscious of our resource use. I’m really happy that we chose to go with LumiGrow. Another company would have given us supplemental lighting, but not the peace of mind.”