Effect of Planting Season, Varieties and Harvesting Times on Biochemical Properties
In Cassava (Manihot esculenta Crantz) Roots
Boonseng O.,1 A. Summart2 and D. Phadkratoke2
1 Rayong Field Crops Research Centre, Muang, Rayong. 20250. Thailand
2 Banmai Samrong Field Crops Experiment Station, Sikhiu, Nakhon Ratchasima. 30340. Thailand
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A study on planting season, varieties and harvesting times affection biochemical properties in cassava roots was conducted on six cassava varieties; Rayong 1, Rayong 60, Rayong 90, Rayong 5, Kasetsart 50, and CMR33-57-81. The data were taken from the cassava roots harvested at 6, 8, 10, and 12 months after planting. The experiments were conducted on the Warin soil series (loamy sand) at Kham Talaesoa Farm, Nakhon Ratchasima in the early and late rainy season (May and October, respectively) 1996. The results indicated that Rayong 90 and Kasetsart 50 gave high average starch content both early and late rainy season plantings. Planting in early and late rainy season gave highest starch content at 8 and 12 months after planting, respectively. There were significant differences in the average content of starch between planting seasons (Table 1).
Biochemical such as lipids and proteins contained in Cassava roots will decrease starch viscosity, (Leach et al., 1959) and cause rancidity in cassava starch. Phenolic compounds causes darkening of cassava starch. Moreover, the toxic cyanide or hydrocyanic acid and dense fiber cause difficulties in industrial starch production process. (Hughes et al., 1994). The result of the study found that Rayong 90 had low lipid, protein, and fiber contents and that Rayong 5 had a low cyanide (only in LRS) and phenolic compounds content. Both lipid and phenolic compounds content were low at 6-8 months after planting. IN addition, protein and fiber contents were low at 12 and 10 months after planting, respectively. Cyanide content was low during rainy season and high during dry season. Soil moisture content was negatively correlated with cyanide content. There were no significant differences between the average contents of lipid, cyanide and phenolic between planting season (Table 1).
There were no significant differences between cassava varieties in amylose content and amylose particle size determines the physicochemical properties of starch (Leach et al., 1959). Harvesting cassava during early rainy season caused a reduction of amylose content and amylose particle size, due to regrowth as amylose was hydrolysis to glucose for energy needed for growth (Table 2).
Reference
Hughes, M.A., Hughes, S. Liddle and Keresztessy, Z. 1994. Biochemistry and molecular biology of cyanogenesis, pp. 385-395. In CIAT The Cassava Biotechnology Network. Proceedings of the Second International Scientific Meeting, Bogor, Indonesia, 22-26 August 1994.
Leach, H,W.,L.D.McCowen, and Schoch, T.J. 1959. Structure of the starch granule I. Swelling and solubility patterns of various straches. Anal Chem. 36 : 535-544
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Table 1 Starch, lipid, protein and cyanide content of six cassava varieties and four harvesting |
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periods when planted on Warin soil series at Nakhon Ratchasima in early (ERS) and late |
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(LRS) rainy season, 1996 |
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Factors |
starch content (%)1/ |
lipid content (%)1/ |
protein content (%)1/ |
cyanide content (%)1/ |
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ERS |
LRS |
ERS |
LRS |
ERS |
LRS |
ERS |
LRS |
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1. Variety |
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Rayong 1 |
22.6 c |
9.0 d |
0.244 |
0.162 bc |
2.244 |
3.167 |
143 |
103 cd |
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Rayong 60 |
23.3 bc |
9.4 d |
0.155 |
0.167 bc |
2.099 |
2.728 |
99 |
139 ab |
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Rayong 90 |
27.9 a |
15.9 a |
0.17 |
0.140 c |
1.775 |
2.659 |
77 |
155 bc |
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Rayong 5 |
24.6b |
13.1 b |
0.228 |
0.182 bc |
2.144 |
2.796 |
167 |
81 d |
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Kasetsart 50 |
26.7 a |
15.5 a |
0.231 |
0.246 a |
2.506 |
3.214 |
95 |
160 a |
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CMR33-57-81 |
24.1 bc |
11.2 c |
0.2 |
0.214 ab |
2.299 |
3.054 |
73 |
107 d |
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LSD 0.05 |
2.0 |
1.5 |
- |
0.058 |
- |
- |
- |
34 |
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CV(%) |
8.9 |
13.1 |
44.1 |
33.2 |
25.9 |
128.9 |
110 |
31.4 |
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2. Harvesting time (month after planting ; MAP) |
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6 MAP |
23.3 bc |
2.3 c |
0.210 |
0.159 b |
2.164 |
30678 a |
10 b |
147 a |
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8 MAP |
27.9 a |
14.4 b |
0.143 |
0.171 b |
2.128 |
3.172 b |
206 a |
95 b |
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10 MAP |
24.9 b |
16.3 a |
0.222 |
0.212 a |
2.144 |
2.495 c |
205 a |
90 b |
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12 MAP |
23.3 b |
16.7 a |
0.243 |
0.198 a |
2.274 |
2.399 c |
16 b |
138 a |
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LSD0.05 |
1.7 |
1.2 |
- |
0.021 |
- |
0.268 |
85 |
28 |
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CV(%) |
10.1 |
14.6 |
65.6 |
20.6 |
15.6 |
123.4 |
116.3 |
34.9 |
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Average2 |
24.9 a |
12.4 b |
0.204 a |
0.185 a |
2.178 b |
2.936 a |
109 a |
117 a |
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1 In column, means followed by a common letter are not significantly difference at P<0.05 by LSD |
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2 In row, means of different planting season in the same characteristic followed by a common letter |
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are not significantly difference at P<0.05 by LSD |
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Table 2 Phenolic content, fiber content, amylose content and amylose size (DPn) of six cassava |
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varieties and four harvesting periods when planted on Warin soil series at Nakhon |
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Ratchasima in early (ERS) and late (LRS) rainy season, 1996. |
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Factors |
phenolic content(%)1/ |
fiber content(%)1/ |
amylose content(%)1/ |
amylose size1/ |
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ERS |
LRS |
ERS |
LRS |
ERS |
LRS |
ERS |
LRS |
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1. Variety |
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Rayong 1 |
0.1233 b |
0.1135 c |
1.756 |
3.061 a |
21.28 |
18.06 b |
2,841 |
3,836 |
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Rayong 60 |
0.1225 b |
0.1230 b |
1.917 |
2.579 ab |
19.45 |
19.69 a |
3,197 |
3,529 |
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Rayong 90 |
0.1215 b |
0.1171b |
1.488 |
2.487 b |
20.11 |
20.22 a |
2,976 |
3,798 |
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Rayong 5 |
0.1121 c |
0.1058 c |
1.625 |
2.377 b |
20.63 |
20.12 a |
3,216 |
3,762 |
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Kasetsart 50 |
0.1367 a |
0.1347 a |
1.661 |
2.292 b |
19.25 |
19.53 a |
2,857 |
3,907 |
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CMR33-57-81 |
0.1186 b |
0.1201 b |
1.771 |
2,166 b |
18.41 |
19.98 a |
2,924 |
3,613 |
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LSD0.05 |
0.0009 |
0.0029 |
- |
0.003 |
- |
1.14 |
- |
- |
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CV(%) |
10.5 |
16.1 |
34.1 |
16.1 |
7.2 |
4.5 |
10.2 |
9.7 |
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2. Harvesting time (month after planting ; MAP) |
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6 MAP |
0.1090 b |
0.1163 c |
1.830 ab |
2.397 bc |
20.60 a |
20.50 a |
2,895 b |
3,384 b |
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8 MAP |
0.1312 ab |
0.0916 d |
1.585 bc |
2.834 a |
20.88 a |
19.04 b |
3,360 a |
3,433 b |
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10 MAP |
0.1118 b |
0.1267 b |
1.426 c |
2.117 c |
17.97 b |
20.58 a |
3,452 a |
3,835 ab |
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12 MAP |
0.1378 a |
0.1416 a |
1.972 a |
2.627 ab |
19.96 a |
18.28 b |
2,301 c |
4,311 a |
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LSD0.05 |
0.0214 |
0.0021 |
0.272 |
0.324 |
1.03 |
1.108 |
286 |
508 |
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CV(%) |
19.8 |
12.3 |
23.7 |
19.2 |
6.1 |
6.6 |
11.1 |
15.8 |
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Average2 |
0.122 a |
0.119 |
1.703 b |
2.494 a |
19.85 a |
19.60 a |
3,001 b |
3,740 |
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1 In column, means followed by a common letter are not significantly difference at P<0.05 by LSD |
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2 In row, means of different planting season in same characteristic followed by a common letter are |
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not significantly difference at P<0.05 by LSD |
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Cassava 2