Evaluation of butterhead lettuce cultivars for winter production under a shadenet structure

Incorrect selection of cultivar leads to profit loss due to variability in yield and in quality characteristics of butterhead lettuce. Nine butterhead lettuce cultivars were evaluated in soil cultivation under a 40% white shadenet structure during the winter season on an experimental farm of the Agricultural Research Council – Vegetable and Ornamental Plant Institute (ARC-VOPI). The experiment was laid out as a randomised complete block design with five replicates. During harvest, 10 plants from each cultivar per replicate were assessed for yield, and five uniform heads were cut longitudinally for internal quality assessment. Quality assessment included compactness, uniformity, tipburn, disease tolerance and bolting tolerance. Results showed that head mass, height, diameter, uniformity, compactness, tipburn, disease tolerance and internal quality were significantly affected by cultivar choice. Recommended cultivars which outperformed the control (Ofelia) based on uniformity, tipburn and percentage marketable harvest were Analena, Fabieto RZ, Lobela and Rousso RZ. Results thus indicate that improved yield and quality of butterhead lettuce cultivars can be obtained by selecting the correct cultivar for winter production.