Evolution of quality parameters of different lettuce (Lactuca sativa L.) varieties under unheated plastic tunnel

The plastic tunnel can ensure a positive effect on the yield and quality of vegetables. In our experiment, we evaluated the following types and varieties of lettuce – heading type (‘Great Lakes 659’, ‘King of May’), non-heading type (‘Lollo Rossa’, ‘Lollo Bionda’), and cos type (‘Romaine lettuce’). The highest head weight was detected in ‘Great Lakes 659’ (373.97 g plant⁻¹) and ‘Romaine lettuce’ (266.79 g plant⁻¹) under an unheated plastic tunnel in springtime. Higher nitrate content (565.0 mg kg⁻¹) was measured for ‘cos lettuce’, while lower values (425.50 mg kg⁻¹) were measured for ‘Lollo Bionda’. Among the varieties, one of the highest dry matter content was also measured for ‘Great Lakes 659’ (8.52%). According to our results for lettuce production, ‘Great Lakes 659’ was detected as having a higher yield and dry matter content and a lower nitrate accumulation.