Articles
AN EVALUATION OF POLYURETHANE FOAM AS A REUSABLE SUBSTRATE FOR HYDROPONIC CUCUMBER PRODUCTION
The trials aimed to compare both new and used Aggrofoam with rockwool in terms of fruit yield and quality and to develop optimum crop management systems.
Richgrow, a newly developed foam, was also evaluated.
Aggrofoam that had been used to grow cucumbers for 1 season (2 crops) previously was compared with new foam and rockwool.
The first cucumber plants were planted in January, and in July a second crop was replanted onto the same slabs.
Results showed that productivity from plants grown on new Aggrofoam slabs was equal to that from rockwool, provided that a suitable irrigation programme was applied.
When cucumbers were planted on Aggrofoam that had been used previously (and steam sterilised before reuse) productivity and fruit quality were equal to or better than that from new foam slabs and from rockwool.
The presence of root material within the slabs improved the water holding capacity of the substrate and this had a beneficial effect on crop performance.
Richgrow, a hydrophilic foam, was compared with new Aggrofoam slabs in a short summer trial.
Fruit production was higher from Richgrow and it did not suffer from drying out.
Tests showed that Aggrofoam was strong and flexible and suffered much less physical damage than rockwool during the steaming process.
Where damage occurred it was minor and did not affect crop performance.
Richgrow was softer and took longer to dry, making it more difficult to steam and resleeve.
Overall, both substrates were shown to be suitable for long season cucumber production.
Aggrofoam was better when it was reused after previous cropping than when it was new.
The long term reusability of Richgrow is currently unproven.