Picture the scene. You're standing in an abandoned greenhouse, at two o'clock in the morning. It's quiet. Very quiet. The employees have gone home, you're all alone. Suddenly, you hear a rustling noise. One by one, the plants start moving, of their own accord...
This is exactly what's happening at a Dutch cucumber grower and a tomato greenhouse, saving the growers 90% labor.
This is exactly what's happening at a Dutch cucumber grower and a tomato greenhouse, saving the growers 90% labor.
These companies are working with the Plant Elevation System (PES). PES is an invention of Atgrow, which in turn is part of Vullings Metaalbewerking en Systemen. This Dutch company, which also produces irrigation systems for mushroom cultivation, developed their first lowering system for the horticulture industry a decade ago. "We developed a system to place at the top of the greenhouse. It had a few disadvantages," director Jan Arts says. "You had to install a complete construction in the greenhouse. That's expensive and blocks out too much light." The way it worked wasn't ideal either: because the plants didn't grow uniformly, they couldn't all be lowered at the same time. "For us, after the first system these things were absolutely necessary before entering the market. The past 8 years, we developed no less than ten systems together with an engineer – and threw nine of them out the window. Now we have a system we can fully get behind: the Plant Elevation System."
PES consists of a molded construction for each plant, hanging from the high wire. Through a thin, transparent air tube, these small plastic systems are interconnected. From the compressor (controlled by a computer), air boosts are sent through the tube. The air boost sets in motion several gears: the plant is lowered by half a centimeter. At the same time, the plant moves forward by the same distance. The compressed air moves from one end of the tube to the other, causing the plants to be lowered a little bit in succession. The system is patented now, and Atgrow will introduce it to the market next year. "Growers can first test it on a part of the acreage," Arts continues. "You don't have to install it on the entire acreage immediately. They can see how it works."
The system can be completely taken apart and disinfected. The material is UV-resistant and reinforced with fiberglass in order to prevent warping. As an extra safeguard, the pulleys also brake automatically.
"It's not a 100% replacement for labor," he continues. "You have to go through it again, for an extra top, or to unroll the pulley a bit more if the plant grows more. But it easily saves 90% of the time needed for lowering." And the system turns out to have even more advantages. One of the growers who works with the system, takes into account the ideal working height for his employees when determining the height of the plants. He then divides his employees across the nursery according to height. "That saves another 15% of labor," Arts calculates. The final, unexpected advantage, is in plant health. "It seems to be a lot better for the plants to do the lowering at night," Arts continues. "The plants have less stress, because the lowering occurs gradually, and can be done when the plant is in rest. This leads to higher yields for the grower."
"It's not a 100% replacement for labor," he continues. "You have to go through it again, for an extra top, or to unroll the pulley a bit more if the plant grows more. But it easily saves 90% of the time needed for lowering." And the system turns out to have even more advantages. One of the growers who works with the system, takes into account the ideal working height for his employees when determining the height of the plants. He then divides his employees across the nursery according to height. "That saves another 15% of labor," Arts calculates. The final, unexpected advantage, is in plant health. "It seems to be a lot better for the plants to do the lowering at night," Arts continues. "The plants have less stress, because the lowering occurs gradually, and can be done when the plant is in rest. This leads to higher yields for the grower."
According to the calculation, the system can lead to improved yields by saving labor for lowering the plants (ca. 90%) and as a result of harvesting at the ideal height (ca. 15%). Atgrow will commission research into the gain regarding the lower stress levels thanks to lowering at night. "All in all, we expect the payback period for tomatoes to be less than three years. For cucumbers, there's more labor involved – then the investment should be recouped within 1.5 to 2 years."
For more information:
Atgrow
www.atgrow.nl