racks to Place Rhizoboxes in Labs, Growth-rooms and greenhouses

Racks allow the save and convenient placement of your root boxes / rhizotrons in laboratory, growth room or greenhouses settings at a standardized angle, facilitating root growth along the transparent front plate. The sturdy design is made to hold (heavy) rhizoboxes filled with soil - adjusted to the different rootbox sizes / weights. Vienna Scientific Instruments offers two rack designs, each with a 40° angle as standard inclination, holding 5 rhizoboxes each:

• Standard racks (with space in-between boxes) allow to remove individual boxes, optional shading pannels are available to protect the roots of individual boxes from light, &
• Compact racks (with NO space in-between boxes), maximizing the amount of root boxes which can be placed e.g. in space-limited growth chambers, growing rooms

Customized rack designs (number of boxes, inclination degree, etc.) are available on request. Light shading plates are available as accessories but theier use does not require different rack geometries - thus they can be retrofitted. See below for a brief overview on the effects of inclination on root visibility in rhizobox studies. We are currently developing new cooling racks for rhizoboxes. 

Filling procedures and the angle of rhizobox placement affect the visibility of roots at the transparent front plate in the 3D rooting space of rhizoboxes. For example, Bonpart et al. (2020) reported that with soil compression against the transparent side (with the back of the boxes opened during filling) and an inclination of 30°, only 42% of  chickpea (Cicer arietinum L.) roots were observed on the front side of root boxes (see Figure). At an inclination of 45° (towards the front), however, 54% of the chickpea root system (in terms of biomass) was visible. When the soil was compressed against the back side (i.e. rootboxes were filled from the front), the fraction of the root system visible on the front side reached approx. 73-75% at inclinations of 30° and 45°, respectively. Bonpart and collagues (2020) reported that the lowest front side root system visibility at an root box inclination of 45° was c. 70%, whereas it was 59% for the rhizobox at an inclination of 30°. Posterior 45° condition resulted in higher maximal front visibility (86%), compared to c. 79% for the posterior 30° condition. In any case, filling of rhizoboxes from the top (i.e. neither front nor back opened) results in setups with highly variable soil densities and has to be avoided. For most comparable results, aim to reach soil densities as common in the target ecosystem - by filling similar amounts of homogenized soil to each box. 

As it is thus clear that filling rhizoboxes with soil has an influence on root visibility, potentially due to the different soil densities at the transparent surface by compression, and potentially affect the experimental outcome in general, the VSI rhizoboxes allow to conveniently fill soil either with a detached front or back plate - meeting researchers choice of experimental set-up. As results on the "best" inclination angle are less clear, but with greater angles towards the front generally resulting in more visible roots, we offer rootbox racks with a standard angle of 40° - providing a compromise between maximizing root visibility and minimizing ground space to place the rhizoboxes. Racks with other inclinations can be produced on demand.

• Bontpart, T., Concha, C., Giuffrida, M. V., Robertson, I., Admkie, K., Degefu, T., ... & Doerner, P. (2020). Affordable and robust phenotyping framework to analyse root system architecture of soil‐grown plants. The Plant Journal, 103(6), 2330-2343.