Determination effect of different color shading nets used under cover on indoor climate factors and yield and quality parameters of lettuce (Lactuca sativa L.)

This thesis was carried out in 4 spring-roofed plastic covered high tunnels with a width of 3 m, a length of 4 m and a roof ridge of 2 m, established in the experimental area of Isparta University of Applied Sciences, Agricultural Research and Application Center. Lettuce (Lactuca sativa L.) plant was used as material in the study. The study was carried out between April and June 2021. In the study, the effect of the use of colored shading net with a shading rate of 55% on plant growth parameters and harvest values in the greenhouse cultivation of lettuce was investigated. For this, control (K), red mesh (KF), blue mesh (MF) and green mesh (YF) high tunnels without shading mesh were used. Temperature, humidity, and radiant energy values were measured at the beginning of the hour. When the hourly average radiation energy values were examined, it was determined that from the largest to the smallest, they were K>KF>MF>YF, respectively. The highest radiated energy values were measured as 708 W.m-2 in the K high tunnel, 578 W.m-2 in the KF high tunnel, 491 W.m-2 in the MF high tunnel and 337 W.m-2 in the YF high tunnel. The highest temperature values were measured at 38.8°C in the K high tunnel, 37.7°C in the KF high tunnel, 36.5°C in the MF high tunnel and 35°C in the YF high tunnel. When the lowest relative humidity value was 20.7% in the K high tunnel, it was 22.7% in the KF high tunnel, 29.1% in the YF high tunnel and 32% in the MF high tunnel. Plant yield, head diameter, height, stem length and number of leaves were measured at the highest value in the MF high tunnel. The plant stem thickness value was measured in the highest K high tunnel. Plant yield values were measured as 4.363 tons.da-1 in MF high tunnel, 4.203 tons.da-1 in YF high tunnel, 3.703 tons.da-1 in KF high tunnel, and 3.303 tons.da-1 in K high tunnel. As a result, when evaluated according to the research subjects, it was decided that the use of blue shading net had a significant effect on the yield and quality parameters of the lettuce plant.