Yoshida - 1981 - Fundamentals of Rice Crop Science

230 FUNDAMENTALS OF RICE CROP SCIENCE
6.7.2. Leaf angle
Crop photosynthesis models indicate that droopy leaves are slightly better than
erect leaves when the LAI is less than 3. And the leaf inclination is not too
important when the LAI is less than 4 (Duncan 1971, Monteith 1965, van Keulen
1976). A LAI of 4 at heading is sufficient to produce about 5 t/ha in both the wet
and dry seasons (see Fig. 6.4). In other words, the leaf angle per se is not important
when grain yield is less than 5 t/ha.
6.7.3. Tillering capacity
High tillering capacity basically relates to the plant’s ability to make maximum use
of space. High tillering is considered more important under subnormal conditions
than under optimal conditions.
6.7.4. Benefits and disadvantages of contrasting plant characteristics
Each plant character has benefits and disadvantages under different conditions.
Under a good environment and with good management, IR8 and similar semidwarf
varieties are ideal. On the other hand. under diverse environments and
different management levels, the problem becomes location and management
specific. There is no single variety that can meet all the requirements set by the
different environment and management levels. Apparently, gains in one aspect are
accompanied by losses in another. In such a situation, it is important for plant
breeders to recognize the benefits and disadvantages of contrasting plant characteristics
(Table 6.7).