Lincoln University


When Stu Larsen was asked to manage the New Zealand Biotron, he knew that Conviron’s growth rooms would be the best fit for this innovative facility.

Having worked with Conviron’s PGV36 and GR48 models in his previous position in the plant science department at Lincoln University, Larsen was familiar with the growth rooms’ capabilities. As the Biotron was to be used primarily for bio-protection research, the ability to control every aspect of plant growth—from soil temperature to air flow—was essential.

“We wanted to test the variety of conditions that exotic pests might survive in,” says Larsen. “To be able to test properly, we decided that a normal growth room situation wouldn’t be sufficient. We wanted to be able to control the soil temperature as well, so we could get a better idea of all the aspects that contribute to the lifespan of an exotic pest.”


Larsen says unexpected issues posed a challenge when the Biotron opened in 2004, but trial and error—and guidance from Conviron—helped smooth out the bumps along the way.

“It took a lot of adjustments to a lot of different areas that I didn’t even think would matter to get the growth rooms to behave in the same way,” says Larsen.

One of those areas was the air supply to the four BDW120 growth rooms, which Larsen worked with Conviron to perfect.

“I’ve found Conviron to be very helpful if issues come up,” Larsen says. “They have talked me through issues on the phone, sent emails, and even logged into our growth room systems to have a look at the problem.”


The Result

The Biotron now has six BDW120 growth rooms, with a rhizotron room beneath each. Together, the growth rooms and the rhizotron rooms allow for tightly controlled conditions in which researchers can monitor the interactions between plants and pests.

In the growth rooms, researchers can adjust the air temperature (from -10 C to 40 C, to within 0.5 degrees of the set point), soil temperature (from 8°C to 20°C, to within 0.5 degrees of the set point), and C02 (from ambient levels to 2,000 ppm). Humidity can also be controlled based on the vapour pressure or the vapour pressure deficit if required, and the light intensity (1,100 µmol per square metre, per second at a maximum) can be set to mimic natural daylight from dusk until dawn.

The rhizotron rooms below each hold four, 0.8 m-diameter rhizotron containers, the tops sitting flush with the growth room floors. These containers can be split down the middle using dividers, so eight rhizotron compartments can be used if necessary. With a series of 60 mm-diameter holes cut into the sides of the rhizotrons, researchers can monitor soil and root conditions by replacing a camera or noninvasively removing samples.

As a PC2 (Physical Containment Level 2) facility, the Biotron is also unique in that it is certified by the New Zealand government to transiently hold, contain, decontaminate and otherwise handle restricted plants and plant material.

Larsen says he’s very pleased with how the Biotron has come together and that there’s little he would change if he had to do it all over again, including his involvement with Conviron.

“I consider it invaluable that we have such a great relationship with Conviron,” Larsen says. “Conviron has been a really good choice for us.”