Evaluation of the effect of closed and perforated plastic tunnel microclimates on leaf expansion and phenological stages of cucumbers

During cold seasons cucumber growth in open air encounters chilling damages. Plastic tunnels provide suitable heat environment to grow cucumber. The aim of this research is to evaluate cucumber phonological stages and leaf area expansion within three different plastic tunnel microclimates to moderate air temperatures and air humidity. Three microclimates of (1) completely closed plastic tunnel (MC), (2) perforated plastic tunnel (MP10), with 100 holes (10 mm in diameter) per m2, and (3) perforated plastic tunnel (MP15), with 100 holes (15 mm in diameter) per m2, as experimental treatments, were employed using a complete block design with tree replications. By employing SNK post-hocthe results showed a significant difference for growth degree-days and leaf area expansion between tunnels. Within MC tunnel phonological stages always were occurred ahead of other treatments. Cucumber leaf numbers and second lateral branches within MC were significantly higher than perforated plastic ones. Late in the season leaf area of MP10 reached MCs. In conclusion, MP10 microclimate with relevant microclimate condition could be a good option for early cucumber production.