The Plantop blocks owe their growing popularity to the new generation of stone wool that GRODAN uses for both its blocks and its slabs. Growers used to regard blocks as vectors for their plants. The introduction of the new generation of stone wool has drastically changed that view. Plant propagators are ever more coming to realise that they are selling ‘plants plus blocks'. The blocks provide important added value to the plants throughout the entire season.
The new hydrophilic stone wool fibres in the Plantop blocks ensure a homogeneous distribution of water. Tests have shown that, irrespective of the employed irrigation strategy, the water content (WC) and EC are distributed more uniformly throughout the block than in the case of the standard stone wool.
A uniform block that adapts to the moisture content of the slab will encourage plants to form new roots from the top of the root system in the block. Those new roots will ensure extra production potential, especially after the longest day.
The water content in the blocks can be more efficiently controlled in the range between 40 and 80%. Rapid resaturation offers extra control possibilities and water and nutrients are readily accessible.
Propagators
The Plantop blocks offer propagators advantages too. The homogeneous distribution of water promotes the development of roots in the upper parts of the block, enabling propagators to supply compact, generative plants with a well-developed, active root system throughout the entire block. Ideal conditions for the start of a new crop.Added advantages are the reduced risks of damage to the roots and of the roots drying out during handling and transport now that the roots are more contained inside the block. On top of that, the Plantop blocks are firm and robust and can tolerate mechanical handling and internal transport in modern propagation processes. Any supporting material used, such as canes, will be firmly contained in the block, ensuring that even fairly large plants will suffer virtually no damage during transport or replanting in slabs.
Pro blocks
Besides the Plantop blocks, GRODAN also supplies Pro blocks, which are used mostly by tomato growers who start to grow their new crops with grow lighting in August already. Thanks to their good capillary action, the Pro blocks can be controlled even more accurately than the standard Plantop blocks. Growers who use grow lighting need larger flowering plants in higher, firmer blocks. Plants with a prolonged propagation period need more volume to ensure sufficient plant stability, extra firmness so that large canes can be inserted in the blocks and substantial resaturation capacity to enable control via irrigation in periods with high night temperatures.Basis for new developments
The good capillary action of the new generation of stone wool creates potential for numerous new developments such as the use of higher slabs and the possibility of growing one plant per slab with GRODAN’s Elite system.The development of the blocks of the new generation of stone wool and the increasing use of larger plants for crops grown with lighting have strengthened one another. “If you have to propagate plants in flower in August and the night temperatures are high you can’t control your crop’s development via the temperature. Your only control element is then your irrigation strategy. With the new generation of stone wool you can postpone irrigation for longer. That’s the difference between a plant of 1.20 metres that’s difficult to control and a more compact plant of one metre that has all it takes,” says Hans van Herk, crop consultant for propagation issues.
For more information
Grodan
GRODAN Group
T: +31 47 53 53 020
F: +31 47 53 53 716
www.grodan.com
