Abstract
Investigations were made for the growth and development of Aphelandra squarrosa cv.‘Dania’ grown under 60%-, 30%-, 16%-, 10%-and 5%-light conditions.
1. The 30%-, 16%-and 10%-light plants were taller than the others. The stem of 5%-light plant was the thinnest of all. Among the others differences in stem thickness were insignificant.
2. For the growth in plant weight 30%-light was the most favourable of all. The total weight of the unshaded plant was not different from that of the 30%-plant in the earlier growth period, but it was considerably small as compared with the latter in the advanced growth period. The most deeply shaded plant did not show the significant increase in dry weight throughout the experimental period.
Leaf growth in weight was larger in the 30%-and 16%-light plants than in the others. The largest leaf area per plant was recorded for the 16%-light plant. The ratio of leaf area to leaf weight, or L/F ratio, became larger with the decrease of light intensity.
3. The longevity of leaf was longer in the more deeply shaded plants than in the unshaded. Plasto chron tended to delay with the increase of shading. Leaf shape was independent on light condition. Unshaded leaves were rugous and greenish yellow in color, while the shaded were smoothed and green or deep green.
4. The formation of flower bud was strongly dependent upon light intensity and was not observed under the more deeply shade.
5. The shapes of light-photosynthesis curves differed with the growth conditions. Those of the unshaded leaves were of sun-plant type compared with the shaded.
6. The proportion of various organs in plant body was influenced with light condition. The root of the deeply shaded plant was small in proportion, while the proportion of leaf was small in the unshaded.
