Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/1998
Publication Date: N/A
Technical Abstract: The quantity and wavelength ratios of reflected light affect many aspects of plant growth. Cotton plants were grown in full sunlight over white or red panels in trickle irrigated field plots. The white panels reflected much photosynthetic light and the same far-red to red ratio (FR/R) as in incoming sunlight, whereas the red panels reflected little photosynthetic light and a higher FR/R to developing bolls. Fibers were longest in bolls that received the higher FR/R. When some of the bolls were shielded from light during development, fibers were longest in unshielded bolls that received the high FR/R during development. The difference in fiber length between shielded and unshielded bolls was greater over red than over white panels, indicating that the higher FR/R impinging on the bolls affected fiber elongation more than the increased amount of photosynthetic light. This is important because FR and the FR/R reflected to developing bolls can be altered by plant spacing, row orientation, plant residues on the soil, and position on the plant.