Potweb: a sustainable initiative to combat pot worm

Levoplant: Innovation and sustainability in the ornamental plant sector

Levoplant, a leading company renowned for its high-quality orchids and Cordyline australis, has a history steeped in innovation. A genuine pioneer, the company displays a strong commitment to sustainability. Erwin van Vliet, cultivation and assortment manager at Levoplant, shares the company’s story, highlighting its technological advancements and the groundbreaking Potweb initiative.

Erwin van Vliet with stunning double-stem white orchids.

From tomato growers to orchid specialists

Founded by Leo van der Voort, Levoplant began its journey in 1969 as a tomato grower. Over the years, the company underwent several transformations, including a shift to potted plants and, ultimately, orchids. The changes were part of a strategic vision spurred by the growing demand for exclusive, high-quality plants.

During the 1990s, Levoplant took a significant step by specialising in orchid production. This was accompanied by a large-scale renovation, including the introduction of cultivation tables, internal transport and an automated delivery system. By strategically aligning with market demand and developing state-of-the-art automated systems, Levoplant was ideally positioned to supply high-quality orchids.

Market demand continued to grow and despite several companies switching to the cultivation of Phalaenopsis orchids, a supply shortage emerged. This prompted an increase in the use of seedlings, with imports arriving from all over the world. However, this influx inadvertently brought unwanted guests and reports of pot worm (Lyprauta cambria) infestations started to appear.

Levoplant, Herenwerf location in the Netherlands.

The challenges of combatting pot worm

Lyprauta cambria, a fungus gnat, lays up to 250 eggs at a time in the bark of pots and can even eject them as part of its reproductive strategy. The hatched larvae target root tips, attracted by their sugars. As they burrow through the entire pot, they prevent root growth and (consequently) plant growth. Pot worm infestation is now the biggest challenge facing orchid production, making an effective solution crucial for maintaining profitable cultivation.

Following the announcement of stricter policies on chemical pesticides, the sector shifted its focus to finding a biological solution. As a result, since the process of applying for new biological control agents can take between six and eight years, the sector launched a forward-thinking initiative by establishing a crop committee. Despite trials with natural remedies, biological insects and worms, Lyprauta cambria proved too persistent. Essentially, existing biological controls were ineffective, necessitating a new approach.

As Erwin van Vliet says, “It’s a bit of a chicken-and-egg situation. If you can prevent the gnat from getting to the bark, it can’t lay eggs. If it can’t lay eggs, there’s no pot worm. It’s simple, really. But how do you go about it?”

The initial idea involved applying netting to individual tables, with each table enclosed to protect plants from the gnats. However, this approach had too many drawbacks. It hindered accessibility to the plants, scouting became difficult, watering was trickier and the netting reduced light penetration. With rising energy prices, reduced light levels alone was enough to warrant exploring alternative solutions. So, in 2016, Erwin started experimenting with various types of pot covers. He worked tirelessly for five years trying to find the most effective covering method. By 2020, the focus had shifted to developing a mechanical application system.

In collaboration with Solvent Engineering, Ter Laak and Opti-flor, Levoplant embarked on developing Potweb. Over a three-year period, they strived to develop a comprehensive solution. Finally, in 2023, Levoplant installed its first machine to automate the process. A year later, after optimising the initial machine, a new version was developed capable of fully automating the ‘pantyhose’ application process.

The fully automated machine puts a pantyhose on each pot.

Potweb — effective and sustainable

Potweb is a specialised pantyhose-like cover that fits around the plant pot, creating an impenetrable barrier that prevents Lyprauta gnats from laying their eggs in the bark. Applied at production speed by an automated machine, each pot gets its own pantyhose cover. The material, specially designed for Potweb based on hosiery used in the clothing industry, is suitable for use in the horticultural sector. Thanks to this barrier, chemical pesticides are no longer necessary. Due to the nature of the material and its placement around the pot, this solution does not affect watering, feeding or climate control. These crucial aspects and the overall cultivation process therefore remain the same for growers.

The innovation offers multiple advantages beyond pest control. It prevents bark spillage, keeping floors and machinery cleaner while reducing manual cleaning. The cover also prevents roots from growing out of the pots. A common issue in orchid cultivation is that roots grow from one pot to another, requiring them to be cut. This not only affects a plant’s quality but also increases losses due to weaker plants. Potweb prevents this. Moreover, during transport, Danish trolleys and vehicles remain clean as bark stays contained within the pots. Thanks to the pantyhose and improved root quality, the risk of the plant coming loose from the bark during immersion watering is also eliminated. In turn, improved root quality results in larger, higher-quality plants, ultimately offsetting costs by reducing second-grade and single-stem plant production.

Pots after application of Potweb.

Levoplant is committed to a more sustainable future

“We want to be 100% sustainable”, Erwin passionately explains. Investing in a machine like this is a big step towards reaching that goal. While exploring biodegradable pantyhose materials to optimise Potweb’s sustainability, Levoplant is also currently looking at ways to reduce water usage in the second phase of cultivation. This would lower energy needs for processes like drying and reduce the amount of water that needs to be sanitised. Levoplant is actively pursuing sustainable pot materials as well. All the pots currently in use are already made from recycled materials. This forward-thinking approach cements Levoplant’s well-deserved position as a pioneer in the sector.

Erwin van Vliet standing among a colourful collection of orchids on the fully automated rolling bench.

Last but not least, Erwin emphasises the importance of collaboration. Seven companies are currently using Potweb. While the research was conducted by Levoplant and the aforementioned associated companies, they have not created a revenue model based on their research activities: “Any company can purchase a Potweb machine for its production process.”