Abstract

Six tomato (Solanum lycopersicon ‘Lindo F1) nursery shades and no shade control were evaluated for their effects on seedling photomorphogenesis and field performances as influenced by variable light transmission through the shades. The shades were constructed with wooden frames and different coloured polyethylene sheets as cover (roof). Different polyethylene colours showed varying effects on all the parameters measured. The control treatment (no shade) and green colour shade transmitted the highest light intensity while black and blue coloured shades received the highest temperature and no shade, the lowest. Early emergence and highest percentage emergence (68.8%) was observed under green shade colour compared to blue, red and non-shaded seedlings that gave 54.2, 60.4 and 52.5%, respectively. The environmental variables, light and temperature created microclimates in each of the shades that differed significantly and influenced physiological activities of the seedlings as evidenced in their yield parameters. Regression analysis revealed that light was more important than temperature in tomato plant growth and development. Evidence from the study revealed that the different coloured shades transmitted different light wave lengths to the seedlings in the nursery and consequently affected seedling performance in the field. Conclusively, tomato nursery under no shade treatment produced high quality seedlings that performed better under field conditions than those seedlings raised in the shade. If shades must be used, green and red colours which are capable of transmitting enough light waves for effective photosynthesis of the seedlings are recommended.

Key words: Light intensity, seedling, photomorphorgenesis, nursery, shade, photosynthesis.