The growth and development of lettuce, coriander and swiss chard in a cold water aquaponic system optimized for lettuce production

Aquaponic research seemed to be characterized by experiments conducted in warm water systems while experiments in cold water systems were almost non-existent per August 2016. The main aim of this thesis was therefore to produce more data on the growth and development of plant species and cultivars in a cold water system. One preliminary study and one comparative study was conducted to examine the growth and development of the lettuce cultivars ‘Frillice’ and ‘Salanova Excite R2’, the coriander cultivar ‘Marino’ and the swiss chard cultivar ‘Bulls Blood’ when grown in an aquaponic system optimized for lettuce production. No significant difference between any of the growth parameters (yield, fresh weight of leaves and roots, fresh weight of leaves per rockwool cube, height and number of leaves, length of roots) and production system was found (p<0.05). The nutrient concentrations of plants, fish and water were analyzed. The largest ‘Frillice’ yield of 19540 g obtained in the preliminary monoculture study was higher than reported from other cold water experiments, but lower than reports from warm water experiments. Results from the comparative study showed that the highest aquaponic yield was produced by ‘Salanova Excite R2’ and ‘Frillice’. The average fresh weights of ‘Salanova Excite R2’ and ‘Frillice’ leaves were significantly higher than ‘Bulls Blood’ and ‘Marino’ leaves (p<0.05). The average leaf weights per rockwool cube of ‘Salanova Excite R2’ and ‘Frillice’ were significantly higher than the leaf weights per cube of ‘Marino’ and ‘Bulls Blood’ (p<0.05). ‘Marino’ produced both significantly heavier and longer roots when compared to the three other cultivars (p<0.05). ‘Salanova Excite R2’ obtained the highest number of leaves (p<0.05) and ‘Marino’ produced the tallest leaf average of all cultivars (p<0.05). The average fish weights and lengths were 122.37 g, 22.07 cm, and 177.67 g, 23.41 cm for bleke (Salmo salar L.) and brown trout (Salmo trutta), respectively. Brown trout was recommended for cold water aquaponic production because it achieved a higher harvest weight and grew faster than bleke. Rainbow trout (Oncorhynchus mykiss) and freshwater prawns (Macrobrachium rosenbergii) might also be good options for nutrient production in aquaponic systems. Nutrient concentrations were similar in the preliminary and comparative studies with the exception of higher sodium concentrations being found in both aquaponic plants and water in the comparative study.Aquaponic forskning så ut til å være preget av eksperimenter utført i varmtvannsanlegg mens eksperimenter utført i kaldtvannsanlegg nesten ikke eksisterte per august 2016. Hovedmålet i denne oppgaven var derfor å produsere mer informasjon omhandlende vekst og utvikling av plantearter og sorter i et kaldtvannssystem. En innledende studie og en sammenliknende studie ble gjennomført for å undersøke vekst og utvikling av salatsortene ‘Frillice’ og ‘Salanova Excite R2’, koriandersorten ‘Marino’ og bladbetesorten ‘Bulls Blood’ i et akvaponisk system optimalisert for salatproduksjon. Det ble ikke funnet noen signifikant forskjell mellom vekstparameterne (avling, ferskvekt av blader og røtter, ferskvekt av blader per steinullkube, bladhøyde og -mengde, og rotlengde) og produksjonssystem (p<0.05). Næringsinnholdet i planter, fisk og vann ble analysert. Den høyeste ‘Frillice’ avlingen på 19540 g oppnådd i den innledende studien var høyere enn det andre kaldtvannseksperimenter oppnådde, men lavere enn det varmtvannseksperimenter oppnådde. Resultatene fra den sammenliknende studien viste at ‘Salanova Excite R2’ og ‘Frillice’ produserte den høyeste akvaponiske avlingen. Gjennomsnittlig ferskvekt av ‘Salanova Excite R2’ og ‘Frillice’ blader var signifikant høyere enn ‘Bulls Blood’ og ‘Marino’ blader (p<0.05). Gjennomsnittlig bladvekt per steinulltkube for ‘Salanova Excite R2’ og ‘Frillice’ var signifikant høyere enn bladvekt per steinullkube for ‘Marino’ og ‘Bulls Blood’ (p<0.05). ‘Marino’ røtter var både signifikant tyngre og lengre sammenliknet med de tre andre sortene (p<0.05). ‘Salanova Excite R2’ produserte signifikant flere blader enn alle andre sorter (p<0.05) og den største gjennomsnittlige bladhøyden ble produsert av ‘Marino’ (p