3.1.1. Agronomic characteristics of varieties in winter-spring crop of 2013 - 2014 and summer-autumn crop of 2014
3.1.1.1. Growth duration of testing varieties
Table 3.1. Growth duration of testing varieties in winter-spring crop of 2013 - 2014 and summer-autumn crop of 2014
Variety SV46 SV181 SVN1 GL105 HT1(check) location QN BT QN BT QN BT QN BT QN BT DX (day) 98 97 94 95 105 106 106 107 98 97 HT (day) 90 91 84 85 93 94 99 100 90 91
Note: DX: winter-spring crop; HT: summer-autumn crop
The results indicated that: New varieties have a longer growth duration in winter-spring crop than summer-autumn crop of 7-12 days. In summer-autumn crop, growth duration of new varieties was shortened dueto high temperature, which was similar to that of Yosida (1981) [115]. Three varieties, SV181, SVN1 and SV46, have short growth duration and suitable to cultivation conditions in winter-spring and summer-autumn crops, while GL105 variety has longer growth duration (100 days in summer-autumn crop). Therefore, it is not suitable to production in summer-autumn crop.
3.1.1.2. Agronomic characteristics of testing varieties
Table 3.2. Agronomic characteristics of testing varieties (plant height, flag leaf area and number of leave per plant)
Variety
Chara cters
Plant height
(cm) Flag leaf area (cm2)
Number of leave per plant
Crop QN BT QN BT QN BT
SV181 DX 99.20a 99.61c 39.09b 40.17a 12.55b 13.34b HT 96.27b 96.80b 38.91b 38.16b 12.19bc 12.86b SV46 DX 99.63a 100.17b 38.85c 37.39c 12.68b 13.21c HT 97.88a 98.56c 35.27c 35.24d 12.20bc 12.09b GL105 DX 91.30b 93.56d 32.45d 33.45e 12.36b 12.91d HT 89.20d 91.35d 31.93d 31.23e 12.21bc 12.35d
8
SVN1 DX 87.16c 88.20e 39.45a 38.73b 13.38a 13.61a HT 86.07e 87.12e 34.18a 35.15d 12.56a 12.98a HT1
(check)
DX 99.22a 102.25a 33.59d 32.91d 12.65b 12.88d HT 98.89c 99.57c 32.06e 32.16e 12.15c 12.41c Note: Letters indicate difference significance groups at 5% level
The results indicated that testing varieties have medium plant height in rank (Table 3.2).
3.1.1.3. Mophological chacracteristics of testing varieties
Table 3.3. Mophological chacracteristics of testing varieties
Variety
Chara
cters Plant type*
Hardness of culm
(score)
Leaf marcescenc
e (score)
Panicle exsertion
(score)
Crop QN BT QN BT QN BT QN BT
SV181 DX E E 1 1 3 3 1 1
HT E E 1 1 3 3 1 1
SV46 DX C C 3 3 5 3 - 5 1 1
HT C C 3 3 5 3 1 1
GL105 DX C C 1 1 3 3 1 1
HT C C 1 1 3 3 1 1
SVN1 DX C C 1 1 3 3 1 1
HT C C 1 1 3 3 1 1
HT1 (check)
DX E E 3 - 5 3 - 5 5 - 7 5 1 1
HT E E 3 - 5 3 - 5 5 - 7 5 - 7 1 1
* E: Erection; C: Compactness
The follow-up results in Table 3.3 show that some of the morphological characteristics of the experimental varieties did not differ much between DX and HT. Testing varieties showed plant type varying from erection to compactness in both crops. SV181, GL105 and SVN1 varieties have good panicle exsertion character. Most of the rice varieties have moderate Leaf marcescence (score 3). Particularly, the SV46 and HT1 varieties turn yellow when ripe (score 5). The testing varieties showed completely Panicle exsertion (score 1).
9
3.1.2. Research on pests and diseases affecting experimental rice varieties in winter-spring crop of 2013 - 2014 and summer-autumn crop of 2014
Table 3.4. Situation of pests and diseases on experimental rice varieties (score)
Variet y
Chara
cters Stem borers Brown spot Sheath
blight Blast
Crop QN BT QN BT QN BT QN BT
SV181 DX 0 0 0 0 0 0 1 - 3 1 -
3
HT 0 0 0 0 0 0 0 0
SV46 DX 1-3 1-3 1 1 1-3 1-3 0 0
HT 1-3 1-3 1 - 3 1 - 3 1-3 1-3 0 0
GL105 DX 0 0 1 1 0 0 0 0
HT 0 0 1 1 0 0 0 0
SVN1 DX 1 1 0 0 0 0 0 0
HT 1 1 0 0 0 0 0 0
HT1 (check)
DX 1 1 5 5 1 1 0 0
HT 1 - 3 1 - 3 5 - 7 5 1 1 0 0
The results of the pest and disease response experiments in Table 3.4 show that the SVN1 and GL105 rice varieties have less affected to pests and diseases.
3.1.3. Yield components of testing rice varieties in winter-spring crop of 2013 - 2014 and summer-autumn crop of 2014
Table 3.5. Yield components of testing rice varieties
Variety
Chara cters
Number of
panicles/m2 Number of seeds/panicle
Percentage of filled seeds (%)
1000 seed weight (gram)
Crop QN BT QN BT QN BT QN BT
SV181
DX 292,00b 295,00b 150,51a 151,38a 82,12a 83,70a 23,66 23,70 HT 289,53ab 291,67b 147,75a 152,64a 81,01a 81,02a 23,56 24,13 SV46
DX 275,00cd 274,67d 142,68e 141,75d 78,60d 79,92e 25,56 25,78 HT 266,50cd 268,67d 144,24d 143,30e 76,46d 77,85e 25,26 25,20 GL105
DX 281,33c 280,33c 148,22b 148,03b 80,00b 81,76b 24,60 24,76 HT 270,37bc 274,00c 147,58b 148,15d 79,02b 80,13c 24,40 24,40 SVN1 DX 301,00a 307,00a 148,34c 149,33b 79,68c 81,18c 24,53 24,68
10
HT 293,85a 296,67a 146,82c 147,04c 78,69d 80,27b 24,30 24,30 HT1
(đ/c)
DX 272,00d 275,00d 151,58d 147,16c 76,16e 80,23d 24,30 24,47 HT 255,45d 259,33e 147,51e 141,77d 74,55e 78,91d 24,27 24,27 Note: Letters indicate difference significance groups at 5% level.
In Quang Binh, rice production in winter-spring crop had more favorable weather conditions than summer-autumn crop, so the yield components (Number of panicles/m2, Number of filled seeds/panicle, Percentage of filled seeds) of productivity in the winter-spring crop were higher than those of the summer- autumn crop, while the 1000 seed weight was not significantly different, which was consistent with Uga et al. (2007) [112].
Table 3.6. Theoretical yield and actual yield of experimental varieties
Variet
y
Charac ters
Theoretical yield (tons/ha)
actual yield (tons/ha)
Theoretic al yield on
the average (tons/ha)
Actual yield compar
ed to check
(%)
Crop QN BT QN BT
SV181 DX 8,5a 8,8b 7,5b 7,6b 7,6 120,8
HT 8,1a 8,7a 7,0b 7,1b 7,0 125,0
SV46 DX 7,8c 7,9d 6,5d 6,6d 6,6 104,6
HT 7,3c 7,5b 6,0d 6,2d 6,1 108,7
GL105 DX 8,2b 8,3c 7.1c 7,2c 7,6 121,7
HT 7,6b 7,8b 6,4c 6,4c 6,4 114,3
SVN1 DX 8,7a 9,1a 7,6a 7,9a 7,8 123,3
HT 8,2a 8,5a 7,1a 7,4a 7,2 127,6
HT1 (check
)
DX 7,6d 7,8d 6,2e 6,3e 6,3 -
HT 6,8d 7,0c 5,5e 5,8e 5,6 -
The results of the study in Table 3.6 show that SV181, SVN1 and GL105 have high actual yields which are resulted from high yield components in Table 3.5. This result is consistent with the results in research of Nguyen Huu Te et al.
(1997) [63].
3.1.4. Results of assessment of productivity stability and adaptability of testing varieties at study sites in winter-spring crop 2013-2014 and summer-autumn crop 2014
11
3.1.4.1. Stability in yield of testing varieties in winter-spring crop of 2013-2014 Table 3.7. Stability in yield of testing varieties in winter-spring crop of 2013- 2014
Varieties Yield (tons/ha)
Yield
(tons/ha) Ttn
Regression Difference
(S2di)
P
SV181 7.6 0.56 1.65 0.87 0.89
SV46 6.6 3.62 14.35* -4.38 0.39
GL105 7.6 1.69 12.33* 5.35 0.32
SVN1 7.7 -0.31 1.80 1.06 0.83
HT1 (check) 6.3 0.23 0.91 2.32 0.76
Note: “*”Difference in level 95%.
The results in Table 3.7 indicated that: In terms of Winter-Spring crop, SV181 and SVN1 varieties gave yielded stable through experimental environments because of the small linear regression (S2di) and P (P<0.95). The SV46 and GL105 are considered stable varieties and have bi value as 3.62 and 1.69, respectively. However, these varieties have regression coefficient bi> 1 and Ttn> T (with an * sign), so they are suitable only in favorable environments and give high productivity in high intensive conditions.
3.1.4.2. Productivity stability of testing varieties in summer-autumn crop of 2014 Table 3.8. Productivity stability of testing varieties in summer-autumn crop of 2014
Varieties Yield (tons/ha)
Yield
(tons/ha) Ttn
Regression Difference
(S2di)
P
SV181 7.0 0.54 1.82 1.08 0.59
SV46 6.1 1.45 0.24 18.20 1.00*
GL105 6.6 0.38 1.73 12.68 0.97*
SVN1 7.2 0.76 0.23 1.02 0.69
HT1 (check) 5.6 0.65 0.47 1.25 0.80
Note: “*”Difference in level 95%.
The results in Table 3.7 indicated that: The SVN1, SV181 varieties are adaptive as well as productive in both winter-spring and summer-autumn seasons in Quang Binh.
12
3.1.4.3. Environmental index of the experiment sites
Table 3.9. Environmental index of the experiment sites (Ij)
Site Environmental index (Ij)
winter-spring crop summer-autumn crop
Bo Trach 0.1 -2.2
Quang Ninh 3.5 3.2
The results presented in Table 3.9 show that the average for both winter- spring and summer-autumn crops is favorable in Quang Ninh province, while in Bo Trach environment is unfavorable or unclear.
3.1.5. Research on grain quality of experimental rice varieties in winter- spring crop 2013-2014 and summer-autumn crop 2014
Table 3.10. Some grain morphology characteristics of testing varieties in winter-spring crop 2013-2014 and summer-autumn crop 2014 in Quang Ninh,
Quang Binh province Varieties Seed length (mm) Seed width
(mm) L /W
DX HT DX HT DX HT
SV181 6.65 6.64 2.31 2.30 2.87 2.88 SV46 6.72 6.72 2.24 2.23 3.00 3.01 SVN1 6.69 6.68 2.42 2.41 2.76 2.77 GL105 4.15 4.14 2.18 2.18 1.90 1.89 HT1(check) 5.98 5.96 2.38 2.37 2.51 2.51
(The experiment was conducted at the Biochemistry Laboratory of the Field Crops Research Institute in 2015)
Table 3.11. Some grain morphology characteristics of testing varieties in winter-spring crop 2013-2014 and summer-autumn crop 2014 in Bo Trach,
Quang Binh province Varieties Seed length (mm) Seed width
(mm) L /W
DX HT DX HT DX HT
SV181 6.66 6.66 2.32 2.31 2.87 2.88 SV46 6.72 6.71 2.24 2.23 3.00 3.00 SVN1 6.70 6.69 2.43 2.41 2.75 2.77 GL105 4.15 4.14 2.19 2.18 1.89 1.89 HT1(check) 5.99 5.97 2.39 2.38 2.50 2.50
(The experiment was conducted at the Biochemistry Laboratory of the Field Crops Research Institute in 2015)
13
Table 3.12. Rice quality characteristics of experimental varieties in winter- spring crop 2013-2014 and summer-autumn crop 2014 in Quang Ninh, Quang
Binh province
Varieties
Amylose content of the grain (%)
Protein (%)
Gel consistency
Gelatinization temperature
DX HT DX HT DX HT DX HT
SV181 17.55 17.60 7.80 7.75 Soft Soft Inter* Inter*
SV46 19.17 19.21 7.56 7.50 Soft Soft Low Low SVN1 14.50 14.56 8.75 8.69 Soft Soft Inter* Inter*
GL105 19.82 19.91 8.90 8.82 Soft Soft Inter* Inter*
HT1
(check) 18.25 18.30 7.23 7.16 Soft Soft Inter* Inter*
(* Intermediate. The experiment was conducted at the Biochemistry Laboratory of the Field Crops Research Institute in 2015)
Table 3.13. Rice quality characteristics of experimental varieties in winter- spring crop 2013-2014 and summer-autumn crop 2014 in Bo Trach, Quang
Binh province
Varieties
Amylose content of the grain (%)
Protein (%)
Gel consistency
Gelatinization temperature
DX HT DX HT DX HT DX HT
SV181 17.50 17.55 7.74 7.75 Soft Soft Inter* Inter*
SV46 19.15 19.17 7.47 7.49 Soft Soft Low Low SVN1 14.45 14.48 8.70 8.64 Soft Soft Inter* Inter*
GL105 19.78 19.83 8.76 8.80 Soft Soft Inter* Inter*
HT1
(check) 18.20 18.26 7.20 7.19 Soft Soft Inter* Inter*
(* Intermediate. The experiment was conducted at the Biochemistry Laboratory of the Field Crops Research Institute in 2015)
Table 3.14. The eating quality indicators of the experimental rice varieties in winter-spring crop 2013-2014 and summer-autumn crop 2014 in Quang Ninh
and Bo Trach districts, Quang Binh province Characters
Varieties
Cooked rice quality (score)
Whiteness Scent Softness Sticky Appetite DX
SV181 4 4 4 4 4
SV46 3 4 4 4 4
SVN1 4 2 4 4 4
14
GL105 3 2 3 3 3
HT1(check) 3 4 4 4 4
HT
SV181 4 4 4 4 4
SV46 3 4 4 4 4
SVN1 4 2 4 4 4
GL105 3 2 3 3 3
HT1(check) 3 4 4 4 4
(The experiment was conducted at the Biochemistry Laboratory of the Field Crops Research Institute in 2015)
Results of grain quality analysis of testing varieties indicate that they are good quality rice cultivars.
The results of the study to identify promising rice varieties show that:
Two rice varieties, SV181 and SVN1, possess many good agronomic characteristics: short growth duration, high yielding, good quality, and suitable to cultivation conditions in both winter-spring and summer-autumn crops of Quang Binh province. Based on the selected varieties, SV181 and SVN1, we conducted a number of techniques for intensive cultivation of these rice varieties like amount of sowing seeds and fertilizer combination which were suitable for production in Quang Binh.