TOMATO GROWN IN CIRCULATING NUTRIENT SOLUTION USING ROCKWOOL AND AS HYDROPONICS

Tomato plants were grown in three closed cultivation systems. System 1 consisted of traditional rockwool mats with drip irrigation and circulating nutrient solution. Systems 2 and 3 were hydroponic systems, where rockwool cubes were half-way submerged in the nutrient solution. In system 3, a biofilter was included.

No significant differences in the total fruit production between hydroponic system no. 2 and the rockwool system were observed, while the yield in the hydroponic-biofilter system was markedly lower. The best quality fruit was produced in the rockwool system.

Analysing hydroponic systems with respect to fungal infection, fewer injuries caused by Pythium spp. and Fusarium spp. were observed on roots grown in the biofilter system. Despite healthy root systems, plant growth in the biofilter system was reduced. Since relatively high temperatures were observed in the hydroponic systems, negative effects on plant growth and fruit production can be postulated. The role of micro-organisms in the biofilter, with respect to growth and fruit production, could not be evaluated.