Greenhouse Lighting: Are Your Tired Grow Lights Letting Your Crop Down?

Researchers and growers alike recognize a lighting truth: A 1% increase in light levels returns a 1% increase in yield. Of course, this only applies when the light level is below the crop’s photosynthetic saturation point. The point at which light limits yield will vary with several factors, including the crop species, crop fertility, and temperature. 

Horticulturalists around the world make cost-effective decisions about lighting every day. In some places for some crops, crop quality during low-light times of the year is maintained by growing cooler and slowing the crop cycle. In other areas, supplemental lighting is added to keep consistent production and quality week after week. For indoor and warehouse cultivation, a stable environment is maintained year-round by sole-source lighting.

Greenhouse lighting plan

Sole-source lighting can be planned to provide consistent, uniform delivery of photons over the crop to provide a consistent harvest. This kind of lighting setup can be achieved with high-pressure sodium (HPRS), metal-halide (MH), or LED lighting technologies.

What happens when HPS and MH bulbs age? 

HPS and MH bulbs generally have a 10,000-hour life. You should expect their output to drop by 10% over this time. That means that a lighting plan initially providing adequate light to meet your yield goals will give you 10% less yield when bulbs hit their recommended end of life. Think about that. What does 10% less yield mean to your bottom line?

While we are thinking about this, what do 10,000 hours mean for a typical indoor production facility?

    • 12 hours/day: 2.25 years

    • 16 hours/day: 1.75 years

    • 18 hours/day: 1.5 years 

The easiest fix for diminishing photon output is to set a maintenance plan to replace your HPS and MH bulbs on a cycle that aligns with your use and sensitivity to decreasing yields. As we come to the end of the year, many operations can achieve tax benefits on Capex equipment purchases delivered prior to January 1, making this is a perfect time to replace your bulbs. 

Let us help you maintain your yields, so you continue to meet your production goals. Ask your Griffin salesperson about options for single end and dead-end HPS and MH replacement bulbs from leading manufacturers, including ParSource, Ushio, Hortilux, and Philips.

Griffin also offers a wide assortment of LED lighting technology. We can help you through the transition from HPS/MH to LED, both on the equipment and culture sides of the equation. 

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Why Are In Vivo Nematodes Beneficial?

Nematodes, specifically Steinernema feltiae, have an intense action against fungus gnat larvae and thrips pupae found in crop media. A popular choice among greenhouse growers of all kinds, this microscopic biological control agent (BCA) has wormed its way into many effective integrated pest management (IPM) programs. Currently, a global SF nematode shortage is affecting many suppliers, leading growers to explore other product options to fill this void.

Nematodes Alternative: Sanitation

Sanitizing surfaces surrounding the growing area can go a long way to controlling fungus gnat and thrips issues. Proper sanitation practices help prevent the spread of algae, which serves as a potential food source and breeding space for several pests such as fungus gnats and shore flies. Products such as ZeroTol 2.0, SaniDate 5.0, and PERPose Plus are often approved for hard surface sanitation and may be used at lower concentrations to reduce the occurrence of algae on soil surfaces or in irrigation piping and tubing.  

Nematodes Alternative BCAs

Though no other BCA is quite as effective as nematodes against fungus gnat larvae and thrips pupae, some preventative pressure can be maintained through strategic applications of different species. Atheta coriaria and Hypoaspis miles, two primarily soil-dwelling BCAs, prey on larvae and pupae at the soil level. These two insects may survive for long periods in the crop media when maintaining even moisture and avoiding incompatible pesticide drenches. Though unable to handle severe infestations on their own, these BCAs may be incorporated into a preventative regimen to keep thrips and fungus gnat pressures low. 

In Vivo Nematodes

Several suppliers offer In Vivo Nematode products. With classic nematode products, nematodes are grown using a fermentation process that occurs in a nutrient solution. In Vivo nematode products are produced following the natural life cycle in live hosts. While both production methods produce effective nematodes, the In Vivo nematodes generally release a more potent dose of the pest-killing bacteria upon infection. It is not uncommon for growers to see slightly faster and higher efficacy with In Vivo nematodes. 

Though global shortages are not currently impacting In Vivo nematode products, this type of production is more labor and time intensive. In Vivo, the application rate for products is lower and would be an appropriate knock-down treatment before beginning a preventative regimen combining adequate sanitation and alternative BCAs. Please reach out to your Griffin sales rep or the GGSPro technical team for crop-appropriate rates and usage tips. 

Products

Product Name		Item Number
Zerotol 2.0 5Gal		71-35481
Sanidate 5.0 5Gal		71-35151
PERpose Plus 5Gal		71-2690
DALOTIAforce 1k beetles		30DC1N
Staphyline 500 beetles		SB0061-01
STRATIOforce 25k mites		30SS25
Hypoline 25K mites		SB0091-04
Sentry 25M nematodes		70-7025
In Vivo NemaShield, 24M nematodes		NEW

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