Vergara - 1976 - Physiological and morphological adaptability of ri

YIELD .-’\.\lD YlELD ("OMPONERWS 0F LOWLAND RICE IN THIE TROPICS 483
Toblo 3. 90mm! variation: in yield and ylold components It four location! In tho tropics‘.
Planting
No. of
Location time crops Variety Range cv
Yin/d [libs]
Los Baios JarL-Dac. 19 19747-92-6 4.21-7.13 15.4
Banqlthon Jan-Dee. 11 RDI 3.49-5.77 13.2
China!
Jan-Dac. 11 IRB 3.70-6.13 13.8
Dec-July a no: 5.11-1.28 12.5
Due-July 8 RD4- 4.B7—7.09 13.5
Due-July 8 64-63 5.33-6.63 9 0
Dee-July 8 1116612140 5 61-784 9 4
Hyderabad July & Jan. 2 IET 1991 7.6 Er 11,6 —
July B- Jan. 2 IE1’ 1039 6.1 & 11.1 —
Spikllat number ( ‘-' fEP/m’)
Lo: Bafios Jan-Dee. 19 lR747-B2-6 29.0-47.0 15.1
Banqkhen Jan-Dec 11 RD1 21.3-28.4 7.9
Jan-Doc. 11 IRB 22.8-29.1 6.9
China! Doc-July 8 RD3 13.1-28.9 12 B
Dec-July 8 R04 23.0-32.6 12.3
Dee-July 8 C4-63 22.0-33.0 12.7
Dec -July B lFl661—140 23.3-35.8 13.8
Hyderabad July Er Jan. 2 IET 1991 57.2 Er 66.1 —
Julyfi Jan. 2 lET 1039 57.1 Er 81.7 —
Grlin weigh! {g_.-’1‘.00O grains)
Los Bafios Jan-Dec. 19 |R747-B2-6 11.2-19.1 2.9
Bangkhen Jan —Dec. 11 FID 27.2-28.6 5.7
Jan-Dec. 11 IRE 27.2-30.1 3.1
Chirlnt Doc-July 8 R03 29.5-32.6 3.8
Doe-July 8 R04 29.4-32.2 2.9
Dec-July B (24-63 24.3-27.3 3.1
Duo-July 8 111661-140 24.7-28.1 3.8
Hyderabad July 5 Jan. 2 lET 1991 20.3 Er 20.3 —
July El Jan. 2 IET 1039 18.3 Er 18.3 -
Filled gains (96)
Los Bafios Jan-Dec. 19 lFl747-B2-6 83.0-95.2 4.0
Bangkhon Jan-Dec 11 R01 66.3-93.5 7.5
Jam-Dec. 11 IFIB 58.4-75.2 9.3
China! Due-July B RD3 91 .7-9E.1 1.7
Dee-July 8 R04 80.0-96.5 6.2
Dee-July 8 (34-53 87.0-92.7 2.3
Dee-July 8 IR661-14O 90.7-94.5 1.4
Hyderabad July 8- Jan. 2 IET 1991 61.0 6 941.3 —
July Er Jan. 2 IET 1039 59.5 Er 82.1 —
'
0am were collected ‘tram Os-ada-Ugflifor Bangiknieni-from Chinchest and Ferrari: (unpublished)
tor Chinat. and from Venkaleswarlu (1973) for Hyderabad.
At Chinat. Thailand. the cv of spikelet number per square meter is as large
as the cv for grain yield; the other two yield components are fairly constant
except for variety RD4. Therefore, at Chinat. grain yield is most closely eorrelated
with spikelet number per square meter.
At Hyderabad. India. both spikelet number and filled-grain percentage seem
to affect grain yields of kharif season. ln khanl season. they have consistently
lower filled-grain percentage than in rabi season.
In Malaysia, the filled-grain percentages of rice crops. regardless of whether
samples were taken from experimental fields or farmers‘ fields. are usually high.
centering around 80 to 90 % (Matsushima. 1962; Moriya. 1968'. Sugimoto, 1968).
Thus. spikelet number per square meter appears to correlate with grain yield.