Effects of three greenhouse cover materials on tomato growth, productivity, and energy use

Abstract Effects of single-layered glass (glass), double inflated polyethylene film (D-poly), and rigid-twin wall acrylic panels (acrylic), as greenhouse covers on tomato (Lycopersicon esculentum Mill) growth, productivity and energy use were investigated over two spring seasons in 1993 and 1994. There was no significant difference in early marketable yield (harvested until April 30) between the D-poly and glass houses. Early marketable yield in the acrylic houses was similar to that in the glass houses, but higher than that in the D-poly houses in 1994. Mid-season yield in the D-poly houses was lower than in the glass houses. Final marketable yield in the D-poly and acrylic houses was similar to that in the glass houses. Fruit size during the early and mid-season in the D-poly houses was smaller than in the glass or acrylic houses. This reduction in fruit size shifted 6–12% of grade # 1 fruit from extra large to large. Fruit size in the glass and acrylic houses was similar. In 1993, there was a higher BER (blossom-end rot) incidence in the glass houses than in D-poly or acrylic houses, but a higher percentage of grade #1 fruit in the D-poly houses than in the glass or acrylic houses. The D-poly and acrylic houses saved 30% in heating energy compared to the glass houses.