Abstract
This study was undertaken in order to find out the relationship between the productive structure and the light extinction coefficient (K) in sugarcane plant communities. Different Ks were obtained for communities of different varieties which had different productive struetures, having straight and erect leaves, or curved and drooping leaves.
A negative correlation (r=-0.7300) was found between Ks and leaf area indies (F) for different vavieties, thus larger Fs were realized in communities with smaller Ks.
A positive correlation was obtained between the ratio, (weight of dead leaves) / (weight of green leaves) in percent and K. Assuming that death of leaves in the lawer part of the community is caused by low illumination near or below the compensation point, the community with smaller K is expected to have a smaller percent of dead leaves, because of its advantage in receiving light effectively.
It was clear that the extinction coefficient was important as index of permeation of light into plant communities of sugarcane varieties, and that the value of this coefficient was dependent upon plant form, such as the angles of leaves in relation to the stem.
