Effects of multifunctional greenhouse film on growth and yield of ‘Green Oak’ and ‘Red Oak’ lettuces (Lactuca sativa L.)

Abstract

Recently, the trend of plant production in the greenhouse has drastically increased. The greenhouse cover film is one of the most important factors on plant growth in the greenhouse. Therefore, National Metal and Materials Technology Center has developed the new multifunctional film that combines the properties of UV filters, near infrared radiation (NIR) reflection and good light diffusion. This experiment aimed to study the effects of multifunction film on the growth and yields of Green Oak and Red Oak lettuces. The experiment was planned completely randomized design (CRD) with 3 treatments which were greenhouses covered with commercial film, MultiTech film and MultiTech-Ultra film. The lettuce plants were put into 8x16 inch planting bags with the soil free planting material consisting of coconut coir: chopped coconut bract at a ratio of 2:1. Providing an Enshi modified fertilizer solution with the concentration 1.2 mS/cm was applied throughout experiment. The result found that 3-week old Green Oak grown under MultiTech cover films showed better growth than those in the greenhouse using commercial cover film. The fresh weight values were 128.8 g/plant accounting for a fresh weight increase of 27.0%. But Green Oak lettuce at 4 weeks old had the fresh weight of the plant and vitamin C content was not statistically different (P > 0.05), with the fresh weight of the plant 296.1–301.0 g/plant and vitamin C quantity 21.2–24.6 mg/100 g fresh weight. Whereas, 4-week old Red Oak grown under MultiTech and MultiTech-Ultra cover films contained weight of 178.3 and 171.7 g/plant or increased 15.7 and 11.4%, respectively when compared to those Red Oak were planted in greenhouse covered with commercial film. However, Red Oak lettuce grown in commercial film greenhouses had the highest vitamin C content of 33.0 mg/100 g fresh weight.