Paul Grootscholten, from the Kester Grootscholten BV plant nursery, the Netherlands

“Our tomatoes thrive on Grotop Master. I consider the good steerability of the slab in particular to be
a major advantage. This applies both to the moisture content and to the EC. The Grotop Master allows
us to reduce the moisture content significantly, if we consider it necessary. Without any negative consequences, we can raise the WC again to a higher level. The advantage of this is that we can steer the
crop better. If I compare the Grotop Master with other slabs, I find that the Grotop Master produces the best root development, with optimum distribution over the slab. Ultimately, you could say that using the Grotop Master leads to a more homogenous quality in our end product. Instinctively, I would say that we achieve an increase in productivity of about 2% thanks to this slab. In short, we achieve good results with the Grotop Master.”

The Grotop Master is already well-known for its unique hydrophilic fibres and the dual-layer slab structure of the Master family. The new production technology means the slab can be resaturated better and faster than before (see illustration). The distribution of the water content and the EC
is also much more even, not only within slabs but also between slabs (see illustration). This gives rise to a greater control range and better root development in the slab.

Why Choose Grotop Master?

The benefits of Grotop Master

Maximum control range

Efficient EC replacement

The improved resaturation capacity and distribution of water throughout the height of the slab offers an opportunity for the improved replacement of the old nutrient solution with new nutrient solution. Even in low-light conditions you need only a minimum amount of water to bring the EC in the slab to the required level. This renders the slab ideally suited to a series of intensive watering sessions of 4% to 5% of the slab volume. This enables you to make efficient use of water and fertilizers and in addition, the EC fluctuations in the slab are less pronounced.

Full root development

The combination of the ‘solid’ top layer and ‘porous’ under layer in the Grotop Master ensures the uniform distribution of WC and EC. Consequently, the roots are distributed more evenly throughout the slab, and more roots are visible compared with the existing Grotop Master. This substantially increases the uptake capacity and assures you of a sturdy plant with maximum disease resistance and vigorous growing power.

Optimum quantity
and quality

The Grotop Master makes it possible to achieve a substantial improvement in the quality and quantity of your crop. Trials carried out by the PPO (the Research Station for Floriculture and
Glasshouse Vegetables in the Netherlands) during the 1990s demonstrate that controlling the water content can increase the yield by 2%. Trials we have recently carried out with the improved Grotop Master slabs demonstrate a similar increase in the crop.

• Single-season slab
• Fibrous structure with two layers: firmer top layer and porous under layer
• Unique hydrophilic fibre readily absorbs water
• Maximum WC control range: 45 to 85% (daytime level)
• Extremely uniform WC and EC distribution throughout the slab
• Good resaturation capacity