Effects of Supplemental Lighting within the Canopy at Different Developing Stages on Tomato Yield and Quality of Single-Truss Tomato Plants Grown at High Density

Responses of Leaf Photosynthesis, Plant Growth and Fruit Production to Periodic Alteration of Plant Density in Winter Produced Single-truss Tomatoes

“…4). Since there is a close relation between the plant vascular system and the photosynthate translocation pathway (Li et al, 2000), an improved light intensity condition, promoting leaf photosynthetic capacity, could eventually contribute to enhanced dry mass production of tomato fruit (Li et al, 2000;Lu et al, 2012). But Higashide et al (2015) also reported that although enhanced maximum photosynthesis rate was observed with elevated CO 2 and fogging in cultivar 'Momotaro York', the fraction of dry matter distribution to fruit was significantly decreased.…”

“…Previous research has reported that when applied with supplemental lighting, the light irradiated on the lower canopy could reach 60% compared with the amount irradiated on the upper canopy (calculated according to Lu et al, 2012). Therefore in this study, we adjusted the PD to obtain a shading index around 40% to guarantee nearly 60% of light could reach the lower canopy, which meant the row distances were 0.…”

“…As plants grow, there is inevitable mutual shading caused by branches and leaves, which leads to light deficiency in the lower canopy (Lu et al, 2012;Steinger et al, 2003). Previous research has shown that insufficient light causes both morphological and physiological changes in plants, such as an increase in specific leaf area and plant height, which maximizes the capture of available light to meet the demand for photosynthesis, but results in more drastic shading.…”

“…In each row of benches, the plant distance was fixed at 0.1 m according to commercial production routine. Two fixed bench distances were set as controls, with row distances of 0.7 and 1.0 m, which gave PDs of 14.3 plants·m −2 (Lu et al, 2012) and 10 plants·m −2 (Kobayashi, 1997(Kobayashi, , 1999, respectively (abbreviated as F14.3 and F10).…”

“…According to previous research, we divided the plant development period into four stages (Lu et al, 2012;McAvoy et al, 1989): Stage 1, after transplanting to anthesis, 21 days; Stage 2, anthesis to initial fruit set, 21 days; Stage 3, fruit set to mature green, 42 days; Stage 4, mature green to red-ripe, 14 days. Previous research has reported that when applied with supplemental lighting, the light irradiated on the lower canopy could reach 60% compared with the amount irradiated on the upper canopy (calculated according to Lu et al, 2012).…”