Comparative water use efficiencies of lettuce plants grown in different production systems

Abstract

Two lettuce (Lactuca sativa) cultivars, namely Paris Island and Maikonig, were grown in nutrient film technique (NFT), aeroponic and rockwool systems for two cultivations during 1993/94 growing season. This study was conducted in order to find out the water use efficiency of both cultivars using the different growing techniques under greenhouse conditions. Paris Island cv. gave significantly higher yield, in terms of vegetative fresh and dry weights, than Maikonig cv. and the NFT system gave significantly higher yield than aeroponic followed by the rockwool in both cultivations. Chlorophyll content was significantly higher in Paris Island cv. than the other cultivar in the first cultivation, while there was insignificant difference in the second. The NFT system showed significantly higher chlorophyll content than the other two treatments in both cultivations. Water use efficiency was 0.59 and 0.47; 0.78 and 0.47 g DW/I for Paris Island and Maikonig in both cultivations, respectively. It was 0.58, 0.58 and 0.43; 0.78, 0.61 and 0.49 g DW/I for NFT, aeroponic and rockwool in both cultivations, respectively. The results showed that former cv. had significantly higher water use efficiency than the latter. As far as cultivation system is concerned, Rockwool showed the lowest water use compared with the other two treatments.