Pedosphere 13(3): 263--270, 2003
ISSN 1002-0160/CN 32-1315/P
©2003 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Dry-matter partitioning, yield and leaf nutrient contents of tomato plants as influenced by shading at different growth stages |
LIU Xian-Zhao1, KANG Shao-Zhong2, YI Hua-Peng1 and ZHANG Jian-Hua3 |
1 Department of Geography and Tourism, Yantai Normal University, Yantai 712100 (China); 2 Northwest Agricultural University, Shaanxi, Yangling 712100 (China); 3 Department of Biology, Hong Kong Baptist University, Kowloon Tong (Hong Kong) |
ABSTRACT |
Pot-grown tomato plants (Lycopersicon esculentum Mill. cv. Maofen) was used to study the effects of three shading levels (0, 75% and 40%) for 8 days on dry matter partitioning, contents of nitrogen (N), phosphorus (P) and potassium (K) in leaves arid yield at three growth stages (early flowering (EF), peak flowering (PF) and later flowering (LF). Shading reduced the dry weight of root and stem tissues at the EF and PF stages, but the 40% shading increased root dry weight and stem dry weight by 43.2% and 21.6%, respectively, at the LF stage. The influence of shading on the dry weight of leaves was very small at most growth stages. Shading had no effects on total leaf N, P and K contents at the EF and PF stages, showing that N, P and K absorption were regulated by the carbon assimilation at these two stages. The leaf N, P and K contents of 40% shaded plants at the LF stage were significantly increased. There were no obvious differences in leaf N and K contents between 75% and 40% shading treatments, but significant difference in leaf P contents was found between them at the LF stage. Shading significantly enhanced the fruit yield of 40% shaded tomato plants at the LF stage, but failed to affect the fruit yield of shaded plants at the EF stage. These showed that tomato could grow well and a better yield could be obtained if some moderate shading (i.e., 40% shading) was applied at the LF stage at summer midday. |
Key Words: dry matter, nutrient, photosynthesis, shading, tomato |
Citation: Liu, X. Z., Kang, S. Z., Yi, H. P. and Zhang, J. H. 2003. Dry-matter partitioning, yield and leaf nutrient contents of tomato plants as influenced by shading at different growth stages. Pedosphere. 13(3): 263-270. |
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