Yoshida - 1981 - Fundamentals of Rice Crop Science

18 FUNDAMENTALS OF RICE CROP SCIENCE
Table 1.6. Effect of nursery method and direct seeding on grain
yield, total dry weight, and harvest index of 3 varieties. IRRI,
1970 dry season. a Grain
produc-
Growth Grain Total
tion per
day in
Nursery Spacing dura- yield dry wt Harvest main
methodb (cm) tion c (t/ha) (t/ha) indexd field
(kg/ha)
lR74782-6-3
Wet-bed 10 × 10 98 7.92 14.1 0.48 102
20 × 20 98 7.23 12.1 0.51 93
Upland 10 × 10 102 7.48 15.5 0.42 91
20 × 20 102 7.32 12.5 0.50 89
Dapog 10 × 10 102 7.88 14.7 0.46 87
20 × 20 102 7.61 13.9 0.47 84
Direct 10 × 10 98 7.36 14.0 0.45 75
seeding 20 × 20 98 7.37 13.3 0.48 75
lR154-18-2-1
Wet-bed 10 × 10 110 7.23 15.2 0.41 80
20 × 20 110 6.98 13.8 0.43 78
Upland 10 × 10 112 6.75 14.7 0.39 73
20 × 20 112 6.75 14.4 0.40 73
Dapog 10 × 10 110 7.22 16.1 0.39 73
20 × 20 110 7.13 14.2 0.43 72
Direct 10 × 10 102 6.89 14.9 0.40 68
seeding 20 × 20 102 6.82 13.5 0.43 67
IR8
Wet-bed 20 × 20 132 8.61 17.2 0.43 77
a
IRRI (1971). b Seedlings were grown for 20 days in the wetbed
nursery and the upland nursery and for 11 days in the dapog
(submerged concrete-lined seedbed) nursery.
c
From sowing to
harvest. d Ratio of grain to total dry matter.
cylinder that encloses all the younger parts of the shoot. The blade is narrow , flat,
and longer than the sheath in all leaves except the second. The ligule is a small,
white, triangular scale that looks like a continuation of the sheath. At the base of
the blade, i.e. around the junction between the blade and sheath, there is a white
band called the collar (Fig. 1.17). A pair of hairy and sickle-shaped auricles are
located at the junction between the collar and the sheath. The presence of welldeveloped
auricles is often used as a convenient guide for differentiating rice from
barnyard grasses, which lack auricles. Some rice varieties, however, lack the
ligule and auricles (liguleless rice).
Most early- to medium-maturing varieties develop about 10-18 leaves on the
main culm. In photoperiod-insensitive varieties the number of leaves is constant
under most conditions. For instance, IR747B2-6 develops 13 leaves and Tainan 3,
15 leaves at Los Baños, Philippines, regardless of the planting season. On the