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European Journal of Applied Sciences – Vol. 11, No. 3
Publication Date: June 25, 2023
DOI:10.14738/aivp.113.14938
Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For
Yield and Yield Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol -
11(3). 555-568.
Services for Science and Education – United Kingdom
Evaluation of F1 Population of Elite Sweet Potato (Ipomoea
batatas (L.) Lam) For Yield and Yield Related Traits in Humid
Rainforest of Umudike, Southeastern Nigeria
Gamaliel I. Harry
Department of Crop Science, Faculty of Agriculture,
University of Uyo, P.M.B 1017, Uyo, Akwa, Ibom State, Nigeria
Joseph I. Ulasi
Department of Crop Science, Faculty of Agriculture,
University of Uyo, P.M.B 1017, Uyo, Akwa, Ibom State, Nigeria
Keyagha E. Rosemary
Department of Crop Science and Technology,
Federal University of Technology, P. M. B. 1526, Owerri, Imo State, Nigeria
ABSTRACT
Sixty-eight sweet potato progenies developed from one common parent (Ligri PC),
were evaluated alongside with national and local checks varieties (Umuspo 3 and
TIS 87/0087) in a two-year replicated field trial under rainfed conditions to identify
superior genotypes with high fresh storage root yield, dry matter, starch and
vulnerability to Cylas puncticollis at the National Root Crops Research Institute,
Umudike, Southeastern Nigeria during the 2015 and 2016 cropping seasons. Yield
and yield related data collected at harvest were subjected to analysis of variance,
correlation analysis and principal component analysis. During the first-year trial,
LPC/13 produced the highest yield of 22.50 tons/ha while LPC/14 produced the
highest yield of 22.56 tons/ha in the second-year trial. LPC/45 had the highest
starch content, 68.79 mg100g-1. Total storage root yield was highly significant (P<
0.01) and positively correlated with marketable root number (r=0.571),
unmarketable root number (r=0.301), marketable root weight (r=0.793) and
unmarketable root weight (r=0.481), respectively. Results from this study showed
that fourteen (14) genotypes had no observable sweet potato weevil damage,
whereas sixteen (16) genotypes had minimal sweet potato weevil damage. Fifteen
(15) genotypes recorded moderate damage caused by sweet potato weevil attack.
Superior genotypes are recommended to be mass produced for cultivation in the
humid rain forest zone of Nigeria and incorporated into sweet potato breeding
program for the development of high-yielding and resistant genotypes.
Keywords: Cylas puncticollis, dry matter, progenies, storage root yield, sweet potato
INTRODUCTION
Sweet potato (Ipomoea batatas (L.) Lam) is a dicotyledonous plant of the Convolvulaceae family
that originated in Northern South America and the southern part of Central America. It is a
cross-pollinated, hexaploidy (2n=6x) crop with 90 chromosomes. Sweet potato is an important
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European Journal of Applied Sciences (EJAS) Vol. 11, Issue 3, June-2023
stable crop that is grown and consumed in temperate and tropical regions around the world
(Thottappilly and Loebenstein, 2009; Afuape et al., 2011). According to FAOSTAT (2012), sweet
potato is the world's sixth most important food crop, following wheat, rice, maize, potatoes,
barley, and cassava. Sweet potatoes have a high carbohydrate content and a low glycemic index
(Burri 2011). Vitamin A, micronutrients (Zn, Fe, Ca, and K), and anti-oxidants are also found in
sweet potatoes (Aywa et al. 2013; Pradhan et al., 2015). Sweet potatoes are grown on an
estimated 9 million hectares with a yield of 13.7 t/ha (FAOSTAT, 2009), with Africa accounting
for approximately 15% of global production (Loebenstein, 2009). Sweet potato yields are high
per unit of time (Nedunchezhiyan et al., 2012) and per area (Nwankwo et al., 2012). Fresh
Sweet potato roots have a low glycemic index due to the slow rate of digestion of its complex
carbohydrate and the slower rate of sugar absorption into the bloodstream. Hence, diabetic
patients can consume it safely (Willcox et al., 2009). Sweet potato is also suitable for use as a
raw material in the food industry due to its starch content (Zhao et al. 2015; Trancoso-Reyes et
al. 2016). Sweet potatoes' starch content accounts for 70% of their dry weight, and a high dry
matter content is a desirable trait that is usually taken into account during selection (Mwanga
et al., 2007).
In Nigeria, sweet potato production is faced with several constraints including sweet potato
weevil infestation caused by Cylas spp. Sweet potato weevil (Cylas puncticollis) is primarily
reported to be a major insect pest damaging sweet potato fresh storage roots in the field. Sweet
potato weevil has been reported to cause severe damage to all harvestable parts of the plant,
resulting in yield losses of up to 80% (Smit et al., 2001; Rees et al., 2003). Sweet potato weevil
could cause a significant decline in quality and lower market value owing to the unappealing
terpenoids released by the crop in response to weevil infestation (Stathers et al., 2003). Sweet
potato is a highly heterozygous plant, allowing for extensive variability within the species that
plant breeders can exploit (Afuape et al., 2011). Identification of superior genotypes with
important agronomic traits is critical for breeding purposes considering the nature and extent
of variability among sweet potato genotypes. Therefore, the objective of this study was to
evaluate sweet potato 68 genotypes obtained through a poly cross system and determine the
extent of variation of quantitative and qualitative traits.
MATERIALS AND METHOD
Experimental Site
The experimental site was located at the National Root Crops Research Institute in Umudike,
Southeastern Nigeria. This experiment was a two-year replicated trial that was conducted
during the 2015 and 2016 cropping seasons.
Umudike is located at latitude 05° 29¢ N, longitude 07° 33¢ E, and elevation 122m above sea
level. Umudike is located in the humid tropics and has an annual rainfall of approximately 2,177
mm, an average annual temperature of approximately 26 °C, and sandy-loamy ultisol soil
(NRCRI, 2012).
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
Table 1: List of sweet potato progenies evaluated in this study and their sources.
Nursery Management
A nursery was established for the propagation of sweet potato seeds. The nursery soil was a 3:
2: 1 mix of topsoil, organic material, and river sand. The nursery was established in the
greenhouse of the National Root Crops Research Institute in Umudike, Southeastern, Nigeria.
After immersing the seeds in cold water for about twenty-four hours to break dormancy, some
of the seeds sprouted and were carefully isolated from the container with cold water and sown
separately in well-watered soil in polyethylene bags containing 1 kg of soil.
S/No. Progenies Sources S/No. Progenies Sources
1. LPC/1 CIP, Ghana 36. LPC/36 CIP, Ghana
2. LPC/2 CIP, Ghana 37. LPC/37 CIP, Ghana
3. LPC/3 CIP, Ghana 38. LPC/38 CIP, Ghana
4. LPC/4 CIP, Ghana 39. LPC/39 CIP, Ghana
5. LPC/5 CIP, Ghana 40. LPC/40 CIP, Ghana
6. LPC/6 CIP, Ghana 41. LPC/41 CIP, Ghana
7. LPC/7 CIP, Ghana 42. LPC/42 CIP, Ghana
8. LPC/8 CIP, Ghana 43. LPC/43 CIP, Ghana
9. LPC/9 CIP, Ghana 44. LPC/44 CIP, Ghana
10. LPC/10 CIP, Ghana 45. LPC/45 CIP, Ghana
11. LPC/11 CIP, Ghana 46. LPC/46 CIP, Ghana
12. LPC/12 CIP, Ghana 47. LPC/47 CIP, Ghana
13. LPC/13 CIP, Ghana 48. LPC/48 CIP, Ghana
14. LPC/14 CIP, Ghana 49. LPC/49 CIP, Ghana
15. LPC/15 CIP, Ghana 50. LPC/50 CIP, Ghana
16. LPC/16 CIP, Ghana 51. LPC/51 CIP, Ghana
17. LPC/17 CIP, Ghana 52. LPC/52 CIP, Ghana
18. LPC/18 CIP, Ghana 53. LPC/53 CIP, Ghana
19. LPC/19 CIP, Ghana 54. LPC/54 CIP, Ghana
20. LPC/20 CIP, Ghana 55. LPC/55 CIP, Ghana
21. LPC/21 CIP, Ghana 56. LPC/56 CIP, Ghana
22. LPC/22 CIP, Ghana 57. LPC/57 CIP, Ghana
23. LPC/23 CIP, Ghana 58. LPC/58 CIP, Ghana
24. LPC/24 CIP, Ghana 59. LPC/59 CIP, Ghana
25. LPC/25 CIP, Ghana 60. LPC/60 CIP, Ghana
26. LPC/26 CIP, Ghana 61. LPC/61 CIP, Ghana
27. LPC/27 CIP, Ghana 62. LPC/62 CIP, Ghana
28. LPC/28 CIP, Ghana 63. LPC/63 CIP, Ghana
29. LPC/29 CIP, Ghana 64. LPC/64 CIP, Ghana
30. LPC/30 CIP, Ghana 65. LPC/65 CIP, Ghana
31. LPC/31 CIP, Ghana 66. LPC/66 CIP, Ghana
32. LPC/32 CIP, Ghana 67. LPC/67 CIP, Ghana
33. LPC/33 CIP, Ghana 68. LPC/68 CIP, Ghana
34. LPC/34 CIP, Ghana 69. Umuspo 3 Local check variety
35. LPC/35 CIP, Ghana 70. TIS 87/0087 National check variety
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Cultural Practices
The trial's field was cleared, ploughed, harrowed and divided into 1.5 m2 (1 m x 1.5 m) plots.
The field was laid out in a complete block randomized design, with two control varieties planted
in each block. The planting area was 1m x 0.3 m in size. Five Sweet potato stands were planted
per plot, for a total of 33,333 stands per hectare. Planting was done in July, after the rain had
become established. Hand weeding was done four weeks, eight weeks, and twelve weeks after
planting (WAP). Compound fertiliser (NPK 15:15:15) was applied at a rate of 400 kg/ha 4 WAP
using the band placement method. Data were collected at 120 days WAP (Ezulike et al., 2001)
for yield and yield-related parameters: number of roots per plot, market and unmarketable
roots per plot, marketable (less than 100 g) and unmarketable (greater than 100 g), yield in
tons per hectare (Levett, 1993).
Determination of Dry Matter
Two marketable size fresh storage roots per genotype were sliced into small pieces and 100g
of each tuber sample was dried in a hot air oven at 80°C for 24 hours until a constant mass was
attained. The dry matter content was calculated by weighing the initial and final weights and
dividing by the percentage of dried weight. Same procedure was used for all replications used.
Dry matter (%) = Dry weight of the tuber / Fresh weight of the tuber x 100
Starch Content Determination
The dry matter content of storage roots was used to calculate starch content. Dry matter was
calculated as a percentage of dry weight to fresh weight of the storage roots using a dry weight
conversion method. The starch content in sweet potato was converted using the formula
described by Wang et al. (1989), y = 0.86945x - 6.34587, where y is the starch content and x is
the dry matter content.
Scoring of Sweet Potato Weevil Incidence and Severity
The Sweet potato storage root tubers in each plot were harvested, and the percentages of tubers
infected by C. puncticollis were determined using a five-point scale (1-5), the severity of the
damage was then indicated for each accession as follows:
• 1 represents 0% (no evidence) of sweet potato weevil (C. puncticollis) damage to sweet
potato tubers.
• 2 represents 1%-25% of sweet potato weevil (C. puncticollis) damage to sweet potato
tubers.
• 3 represents 26%-50% of sweet potato weevil (C. puncticollis) damage to sweet potato
tubers.
• 4 represents 51%-75% of sweet potato weevil (C. puncticollis) damage to sweet potato
tubers.
• 5 represents 76%-100% of sweet potato weevil (C. puncticollis) damage to sweet potato
tubers.
Data Analysis
Harvest data were subjected to Analysis of Variance (ANOVA), and mean separation was
performed using the Least Significant Difference (LSD) test at a 5% level of significance.
Pearson's correlation analysis was used to determine the relationship between yield and yield-
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
related components of sweet potato genotypes. All of the studied characters were also
subjected to principal component analysis (PCA) (Sneath and Sokal, 1993).
RESULTS AND DISCUSSION
Table 2 shows the analysis of variance of yield and yield-related traits during the first cropping
season. The analysis of variance revealed significant (P< 0.05) differences between genotypes
for marketable root weight, unmarketable root weight, yield, dry matter, and starch contents,
but no significant differences for marketable root number, unmarketable root number, Cylas
incidence, and Cylas severity (Table 2). There was no significant difference (P< 0.05) in the
number of marketable storage roots during the first cropping season. The total number of
marketable roots produced ranged from 1.67 by LPC/30 to 15.44 by LPC/47. The number of
unmarketable roots ranged from 0.00 to 6.33, as measured by LPC/8 and LPC/57. During the
first cropping season, the marketable root weights of the sweet potato genotypes studied varied
significantly (P< 0.05). LPC/30 and LPC/13 recorded marketable root weights ranging from
0.38 kg to 12.13 kg. Similarly, during the first cropping season, the unmarketable root weights
of the sweet potato genotypes studied showed no significant difference (P< 0.05). LPC/51 and
LPC/13 recorded unmarketable root weights ranging from 0.00 kg to 1.73 kg. There was
significant difference (P< 0.05) in the yields of the sweet potato genotypes studied during the
first cropping season. LPC/13 produced the highest yield of 22.50 tons/ha, while LPC/30
produced the lowest yield of 2.76 tons/ha. The fresh storage root yield of both checks used in
the study Umuspo 3 and TIS 87/0087 were 11.84 t/ha and 10.73 t/ha, respectively (Table 2).
Table 2 also revealed that twelve (12) genotypes produced storage root yields greater than 13
tons/ha, which higher than the yield of both checks used in the study. These genotypes include;
LPC/13 (22.50 tons/ha), LPC/12 (21.33 tons/ha), LPC/14 (19.83 tons/ha), LPC/15 (17.44
tons/ha), LPC/47 (17.33 tons/ha), LPC/35 (17.33 tons/ha), LPC/11 (15.56 tons/ha), LPC/17
(14.83 tons/ha), LPC/4 (14.44 tons/ha), LPC/48 (14.39 tons/ha), LPC/6 (13.22 tons/ha), and
LPC/38 (13.22 tons/ha). Table 2 further revealed that five genotypes produced fresh root
yields less than five (5) tons/ha in the first year. LPC/60 (4.89 tons/ha), LPC/8 (4.48 tons/ha),
LPC/58 (4.44 tons/ha), LPC/66 (3.84 tons/ha), and LPC/30 (2.76 tons/ha) are among the
genotypes. Cylas incidence and Cylas severity were significantly different (P< 0.05) as shown in
Table 2. During the first year of the trial, Cylas incidence ranged from 0.00 to 3.00. LPC/15 and
LPC/30 recorded the maximum and minimum number of Cylas incidence, respectively.
Similarly, during the first year of the trial, the severity of Cylas ranged from 0.00 to 3.3. LPC/56
recorded the maximum Cylas severity while LPC/30 recorded the minimum Cylas severity.
Table 2 also revealed that fourteen (14) genotypes had no observable sweet potato weevil
damage, while sixteen (16) genotypes had minimal sweet potato weevil damage. Fifteen (15)
genotypes recorded moderate damage caused by sweet potato weevil attack. The result
presented in Table 2 showed that dry matter and starch contents differ significantly (P< 0.05).
The starch content ranged from 68.79 mg100g-1 to 13.63 mg100-1. LPC/45 had the highest
starch content (68.79 mg100g-1) while LPC/25 had the lowest starch content (13.63 mg100-1).
Twenty-one (21) genotypes recorded starch content above 50mg100-1, among which are
LPC/45 (68.79 mg100-1), LPC/42 (64.57 mg100-1), LPC/44 (63.95 mg100-1), LPC/38 (58.90
mg100-1), LPC/48 (58.61 mg100-1), LPC/43 (57.73 mg100-1) and LPC/31 (56.86 mg100-1). The
mean values of the dry matter of the genotypes ranged from 49.90 % to 26.15 %. LPC/36
recorded the highest dry matter (49.90 %) while LPC/25 had the lowest dry matter (26.15 %).
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Among the sixty-eight (68) genotypes evaluated, fifty-five (55) had dry matter content above
40%.
Table 3 presents the analysis of variance of yield and yield-related traits during the second
cropping season. The analysis of variance revealed significant (P< 0.05) differences among
genotypes for unmarketable root number, marketable root weight, unmarketable root weight,
yield, dry matter, and starch contents, but there were no significant differences for marketable
root number, Cylas incidence, and Cylas severity (Table 3). There was no significant difference
in number of marketable storage roots among the genotypes during the second cropping
season. The total number of marketable roots produced ranged from 2.67 by LPC/67 to 14.78
by LPC/12. However, there was significant difference (P< 0.05) in the number of unmarketable
storage roots. The number of unmarketable roots ranged from 0.00 to 7.67, as measured by
LPC/8 and LPC/30. During the second cropping season, the marketable root weights of the
sweet potato genotypes studied vary significantly (P< 0.05). LPC/30 and LPC/13 recorded
marketable root weights ranging from 0.57 kg to 12.13 kg. Similarly, during the second
cropping season, the unmarketable root weights of the sweet potato genotypes studied differ
significantly (P< 0.05). LPC/30 and LPC/13 recorded unmarketable root weights ranging from
0.00 kg to 1.69 kg. The yields of the sweet potato genotypes studied differed significantly (P<
0.05) during the second cropping season. LPC/14 produced the highest yield of 22.56 tons/ha,
while LPC/27 produced the lowest yield of 4.29 tons/ha. The fresh storage root yield of both
checks used in the study Umuspo 3 and TIS 87/0087 were 9.84 t/ha and 10.40 t/ha,
respectively (Table 3). Table 3 also revealed that eleven (11) genotypes produced storage root
yields greater than 13 tons/ha, which higher than the yield of both checks used in the study.
These genotypes include; LPC/14 (22.56 tons/ha), LPC/13 (21.23 tons/ha), LPC/17 (19.79
tons/ha), LPC/12 (17.94 tons/ha), LPC/15 (17.76 tons/ha), LPC/35 (17.33 tons/ha), LPC/47
(14.44 tons/ha), LPC/16 (14.22 tons/ha), LPC/48 (13.94 tons/ha), LPC/35 (13.45 tons/ha) and
LPC/34 (13.09 tons/ha). Cylas incidence and severity also differed significantly in Table 3.
During the second year of the trial, Cylas incidence ranged from 0.00 to 3.00. LPC/15 and
LPC/30 recorded the maximum and minimum number of Cylas incidence, respectively.
Similarly, during the second year of the trial, the severity of Cylas ranged from 0.00 to 3.3.
LPC/56 recorded the maximum Cylas severity while LPC/30 recorded the minimum Cylas
severity. Table 3 also revealed that thirteen (13) genotypes had no observable sweet potato
weevil damage, whereas seventeen (17) genotypes had minimal sweet potato weevil damage.
Twenty (20) genotypes recorded moderate damage caused by sweet potato weevil attack. The
result presented in Table 3 showed that dry matter and starch contents differ significantly (P<
0.05). The results of this study agree with those of (Islam and Shimu, 2018), who reported a
tuberous root yield of 9.0 t/ha at 120 DAP. The total storage root yield range mean values in
this study are consistent with the findings of Ulasi et al. (2021), who reported a range of
2.00t/ha to 16.02t/ha for the storage fresh root yield of sweetpotato genotypes. The fresh
storage root yields observed in this study were lower than the yield (ranging from 18 to 30
t/ha) reported by the CSIR-Crops Research Institute (MoFA, 2014). According to Vimala and
Hariprakash (2011), varieties, location, climate, pests, diseases, and the breeding system all
influence sweetpotato yield and dry matter content variation. Dry matter content is an
important trait in sweet potato selection, second only to root yield. The dry matter content has
been identified as a root quality indicator. According to Vimala and Haripra-kash, (2011), high
dry matter content is an essential objective in sweet potato breeding programs. Dry matter
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
content is impacted by variety, location, climate, incidence of pests and diseases, cultural
practices and soil types. This study observed that twelve (12) genotypes produced storage root
yields greater than 13 tons/ha, which was higher than the yield of both checks used in this
investigation. These genotypes could be incorporated in multi-locational trials to confirm yield
consistency in a diverse of environmental conditions. The dissimilarity in response to sweet
potato weevil infestation could be attributed to differences in genetic constitution,
environmental conditions, and storage root morphology (Stevenson et al., 2009). In this study,
the varied reaction of the sweet potato genotypes to Cylas spp. could be attributed to
environmental conditions as well as variation in genetic constitution which is responsible for
the effect of chemical elements in the storage roots Anyanga et al., 2013). According to
Stevenson et al. (2009), there is a significant level of hydroxylcinnamic acid esters in root latex
and caffeic and coumaric acid esters in epidermal and root surface (Anyanga et al., 2013) were
chemical elements found in the fresh storage roots of sweet potatoes.
Table 2: Mean values of sweet potato progenies for root yield and nutritional traits for
first year trial
Genotypes MRN URN MRW URW Yield Cylas
incidence
Cylas
severity
Dry
matter
Starch
LPC/1 11.71 4.00 4.20 1.27 7.34 0.00 0.00 48.65 31.58
LPC/2 8.00 4.00 3.33 1.17 9.89 0.33 0.67 39.63 35.54
LPC/3 10.67 3.33 5.33 1.60 10.99 0.00 0.00 48.09 33.97
LPC/4 10.33 5.67 6.17 1.47 14.44 1.00 1.00 45.87 23.73
LPC/5 10.67 4.33 5.47 1.20 10.11 0.00 0.00 34.67 19.84
LPC/6 5.78 4.00 5.03 1.70 13.22 1.67 0.67 48.30 21.58
LPC/7 4.67 5.33 2.93 1.63 5.00 1.33 2.00 47.81 24.14
LPC/8 5.53 6.33 3.40 1.37 4.83 0.67 0.67 46.99 24.30
LPC/9 11.11 4.67 5.63 1.50 9.50 0.00 0.00 46.33 24.08
LPC/10 10.33 4.33 6.83 1.20 11.89 0.00 0.00 41.31 21.16
LPC/11 12.70 5.00 7.17 1.00 15.56 1.67 0.67 48.26 26.49
LPC/12 14.11 4.00 9.78 1.60 21.33 0.33 1.00 48.86 28.49
LPC/13 12.00 5.33 12.13 1.73 22.50 0.33 1.00 47.20 26.27
LPC/14 12.67 4.00 11.00 1.17 19.83 0.00 0.00 47.78 29.44
LPC/15 5.00 3.67 6.63 0.67 17.44 3.00 2.33 39.05 22.67
LPC/16 3.67 2.33 1.28 0.13 9.42 0.67 2.00 47.05 21.13
LPC/17 4.33 3.33 2.10 0.13 14.83 2.00 1.67 45.59 21.41
LPC/18 2.67 2.67 1.43 0.13 10.44 0.33 1.00 41.78 20.20
LPC/19 3.33 2.67 1.53 0.10 10.89 0.67 1.67 44.38 20.05
LPC/20 3.00 1.00 1.12 0.03 7.64 0.00 0.00 48.23 26.16
LPC/21 3.67 2.33 1.17 0.09 8.37 0.33 0.67 47.21 21.84
LPC/22 3.33 2.67 1.10 0.06 7.73 0.00 0.00 33.31 16.15
LPC/23 2.67 3.67 0.70 0.15 5.64 1.00 1.00 45.67 25.47
LPC/24 3.00 2.00 1.17 0.03 7.95 0.33 0.67 43.50 25.85
LPC/25 2.67 2.33 0.85 0.02 5.75 0.33 0.67 26.15 13.63
LPC/26 3.33 2.67 1.07 0.06 8.31 2.00 3.33 45.22 22.48
LPC/27 4.00 2.67 0.80 0.05 6.20 0.33 0.67 39.46 19.89
LPC/28 3.00 3.67 1.02 0.13 9.42 3.00 2.67 45.15 42.15
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LPC/29 3.00 2.67 0.80 0.07 5.75 0.00 0.00 48.41 51.22
LPC/30 1.67 1.67 0.38 0.03 2.76 0.00 0.00 47.65 53.48
LPC/31 2.67 2.00 1.00 0.03 6.84 0.00 0.00 43.79 56.86
LPC/32 3.33 0.67 0.78 0.03 5.42 1.00 2.00 48.17 51.45
LPC/33 4.33 1.67 1.50 0.13 11.70 2.00 1.67 45.70 43.47
LPC/34 3.67 3.00 1.63 0.20 10.50 1.33 2.00 40.12 44.21
LPC/35 9.78 2.00 3.60 0.84 16.96 0.67 1.67 41.80 54.77
LPC/36 8.84 2.67 2.20 0.47 7.50 0.00 0.00 49.90 49.43
LPC/37 7.67 1.67 2.23 0.76 7.01 0.67 1.33 48.15 50.49
LPC/38 11.00 2.33 4.40 0.90 13.22 0.33 0.67 42.49 58.90
LPC/39 10.00 4.67 3.37 0.60 10.49 0.33 0.33 48.60 50.85
LPC/40 9.00 2.33 3.23 0.75 7.77 1.33 1.00 47.74 53.82
LPC/41 4.11 3.00 1.83 1.02 6.11 2.00 2.67 46.33 53.26
LPC/42 5.00 4.33 1.60 0.70 7.63 2.33 2.67 39.46 64.57
LPC/43 4.53 3.67 2.03 0.79 5.40 1.00 1.33 44.43 57.73
LPC/44 11.44 2.33 4.27 0.80 11.39 1.00 1.67 38.46 63.95
LPC/45 10.33 3.00 3.47 0.47 8.72 0.33 0.67 35.87 68.79
LPC/46 11.03 3.00 3.63 0.63 9.28 0.00 0.00 43.92 54.78
LPC/47 15.44 2.00 7.47 1.03 17.33 0.33 1.00 42.40 55.48
LPC/48 13.33 4.33 6.13 0.77 14.39 1.33 2.00 39.92 58.61
LPC/49 14.33 2.33 5.87 0.57 13.05 2.00 2.00 48.02 54.07
LPC/50 4.33 1.33 1.07 0.10 7.78 1.00 1.00 47.67 43.71
LPC/51 4.00 0.00 0.87 0.00 5.78 0.33 0.67 40.29 43.03
LPC/52 2.67 0.67 0.70 0.06 5.06 0.67 0.33 47.80 44.18
LPC/53 3.67 1.33 1.13 0.07 8.00 0.67 0.67 46.42 49.41
LPC/54 3.00 3.00 0.72 0.13 5.24 0.33 1.00 33.13 46.40
LPC/55 3.00 1.67 1.08 0.07 7.64 2.00 2.33 41.58 40.41
LPC/56 4.00 1.33 1.20 0.09 8.62 2.33 3.33 48.61 44.33
LPC/57 4.33 0.00 1.07 0.00 7.17 2.00 2.00 47.49 44.27
LPC/58 2.67 0.67 0.60 0.07 4.44 1.00 1.33 45.10 42.84
LPC/59 2.67 1.33 0.73 0.07 5.33 1.33 2.67 47.82 45.07
LPC/60 3.00 1.33 0.60 0.13 4.89 0.33 0.33 46.71 50.06
LPC/61 3.00 1.33 1.13 0.07 8.00 1.00 2.33 45.94 50.02
LPC/62 3.33 1.33 1.22 0.03 8.31 0.67 1.00 43.48 49.28
LPC/63 3.33 1.33 1.03 0.03 7.09 0.67 0.33 45.77 54.11
LPC/64 3.00 2.33 0.73 0.09 5.49 1.00 1.33 36.72 49.03
LPC/65 3.33 1.67 0.93 0.06 6.64 1.33 2.67 42.46 44.83
LPC/66 2.33 1.00 0.47 0.11 3.84 0.67 0.67 46.07 46.82
LPC/67 3.00 1.33 1.10 0.07 7.78 1.33 3.00 41.87 44.72
LPC/68 4.00 2.67 1.20 0.17 9.22 1.33 1.33 39.14 41.47
Umuspo 3 4.00 1.00 1.60 0.00 11.84 2.00 1.00 43.75 25.36
TIS 87/0087 10.44 1.33 3.27 0.80 10.73 0.00 0.00 40.49 23.73
Total 6.14 2.65 2.78 0.50 9.35 0.88 1.14 44.02 39.47
LSD (P<0.05) NS NS 5.06 1.09 7.90 NS NS 7.51 16.97
MRN = Marketable root number, URN = Unmarketable root number, MRW = Marketable root weight, URW =
Unmarketable root weight
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
Table 3: Mean values of sweet potato progenies for root yield and nutritional traits for
second year trial
Genotypes MRN URN MRW URW Yield Cylas
incidence
Cylas
severity
Dry
matter
Starch
LPC/1 8.84 3.00 2.13 0.52 7.37 0.00 0.00 48.65 31.58
LPC/2 7.33 4.00 3.27 1.15 6.22 0.33 0.67 39.63 35.54
LPC/3 10.67 3.00 5.37 1.57 10.96 0.00 0.00 48.09 33.97
LPC/4 9.67 6.00 6.03 1.43 12.11 1.00 1.00 45.87 23.73
LPC/5 9.33 5.67 5.33 1.23 9.44 0.00 0.00 34.67 19.84
LPC/6 4.78 4.33 4.33 1.63 8.10 1.67 0.67 48.30 21.58
LPC/7 4.00 5.00 2.22 1.56 4.81 1.33 2.00 47.81 24.14
LPC/8 4.87 7.67 2.60 1.39 5.65 0.67 0.67 46.99 24.30
LPC/9 11.11 5.67 5.43 1.53 10.59 0.00 0.00 46.33 24.08
LPC/10 10.00 5.00 6.63 1.15 11.98 0.00 0.00 41.31 21.16
LPC/11 11.70 5.33 6.37 1.03 12.67 1.67 0.67 48.26 26.49
LPC/12 14.78 4.00 9.87 1.60 17.94 0.33 1.00 48.86 28.49
LPC/13 12.00 4.33 12.13 1.69 21.23 0.33 1.00 47.20 26.27
LPC/14 13.67 4.67 11.40 1.20 22.56 0.00 0.00 47.78 29.44
LPC/15 4.67 4.33 6.53 0.67 17.76 3.00 2.33 39.05 22.67
LPC/16 4.67 2.67 1.93 0.20 14.22 0.67 2.00 47.05 21.13
LPC/17 4.67 3.00 2.77 0.20 19.79 2.00 1.67 45.59 21.41
LPC/18 4.00 1.67 2.40 0.10 16.68 0.33 1.00 41.78 20.20
LPC/19 3.67 1.00 1.87 0.07 12.90 0.67 1.67 44.38 20.05
LPC/20 3.33 0.67 1.30 0.07 9.11 0.00 0.00 48.23 26.16
LPC/21 4.00 0.67 1.40 0.07 9.77 0.33 0.67 47.21 21.84
LPC/22 4.00 1.67 1.40 0.03 9.53 0.00 0.00 33.31 16.15
LPC/23 3.00 3.00 0.73 0.17 5.99 1.00 1.00 45.67 25.47
LPC/24 3.33 2.00 1.27 0.07 8.86 0.33 0.67 43.50 25.85
LPC/25 3.33 2.00 1.32 0.00 8.75 0.33 0.67 26.15 13.63
LPC/26 3.33 2.67 0.93 0.06 6.64 2.00 3.33 45.22 22.48
LPC/27 3.67 2.67 0.57 0.08 4.29 0.33 0.67 39.46 19.89
LPC/28 2.67 3.67 0.82 0.12 6.18 3.00 2.67 45.15 42.15
LPC/29 4.00 1.33 1.22 0.03 8.29 0.00 0.00 48.41 51.22
LPC/30 2.67 0.00 0.78 0.00 5.20 0.00 0.00 47.65 53.48
LPC/31 2.67 1.00 1.00 0.00 6.64 0.00 0.00 43.79 56.86
LPC/32 3.67 1.67 1.28 0.03 8.73 1.00 2.00 48.17 51.45
LPC/33 4.67 1.33 1.85 0.10 12.95 2.00 1.67 45.70 43.47
LPC/34 4.33 2.33 1.80 0.17 13.09 1.33 2.00 40.12 44.21
LPC/35 10.11 2.67 3.60 0.87 13.45 0.67 1.67 41.80 54.77
LPC/36 8.84 3.67 2.53 0.47 9.70 0.00 0.00 49.90 49.43
LPC/37 8.33 2.33 2.57 0.73 9.05 0.67 1.33 48.15 50.49
LPC/38 10.33 2.67 4.00 0.90 10.53 0.33 0.67 42.49 58.90
LPC/39 9.33 4.33 3.13 0.55 8.98 0.33 0.33 48.60 50.85
LPC/40 9.67 2.00 3.55 0.70 9.53 1.33 1.00 47.74 53.82
LPC/41 4.44 3.33 1.93 1.03 6.89 2.00 2.67 46.33 53.26
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LPC/42 5.00 4.00 1.53 0.69 7.34 2.33 2.67 39.46 64.57
LPC/43 5.20 3.33 2.30 0.77 7.06 1.00 1.33 44.43 57.73
LPC/44 10.78 1.67 3.97 0.77 9.16 1.00 1.67 38.46 63.95
LPC/45 10.00 3.00 3.33 0.43 7.61 0.33 0.67 35.87 68.79
LPC/46 10.37 3.33 3.27 0.67 7.05 0.00 0.00 43.92 54.78
LPC/47 14.78 2.00 7.03 1.03 14.44 0.33 1.00 42.40 55.48
LPC/48 13.33 4.00 6.07 0.77 13.94 1.33 2.00 39.92 58.61
LPC/49 14.00 2.00 5.87 0.53 12.83 2.00 2.00 48.02 54.07
LPC/50 4.33 1.33 1.07 0.10 7.78 1.00 1.00 47.67 43.71
LPC/51 4.00 0.00 0.87 0.00 5.78 0.33 0.67 40.29 43.03
LPC/52 3.00 0.33 0.97 0.03 6.62 0.67 0.33 47.80 44.18
LPC/53 4.00 1.33 1.43 0.07 10.00 0.67 0.67 46.42 49.41
LPC/54 3.00 3.33 0.92 0.13 6.57 0.33 1.00 33.13 46.40
LPC/55 2.67 2.00 0.90 0.06 6.40 2.00 2.33 41.58 40.41
LPC/56 3.67 2.33 1.07 0.13 7.95 2.33 3.33 48.61 44.33
LPC/57 4.33 0.33 0.97 0.03 6.69 2.00 2.00 47.49 44.27
LPC/58 3.00 0.33 0.90 0.03 6.28 1.00 1.33 45.10 42.84
LPC/59 2.67 0.67 0.73 0.03 5.11 1.33 2.67 47.82 45.07
LPC/60 2.67 1.67 0.70 0.13 5.55 0.33 0.33 46.71 50.06
LPC/61 3.00 1.33 1.10 0.10 8.00 1.00 2.33 45.94 50.02
LPC/62 3.33 0.00 1.25 0.00 8.31 0.67 1.00 43.48 49.28
LPC/63 4.33 0.00 1.45 0.00 9.62 0.67 0.33 45.77 54.11
LPC/64 3.67 2.00 0.90 0.06 6.35 1.00 1.33 36.72 49.03
LPC/65 3.00 3.33 0.87 0.09 6.35 1.33 2.67 42.46 44.83
LPC/66 2.67 1.67 0.57 0.11 4.53 0.67 0.67 46.07 46.82
LPC/67 2.67 1.00 0.90 0.08 6.55 1.33 3.00 41.87 44.72
LPC/68 3.33 1.67 1.07 0.10 7.77 1.33 1.33 39.14 41.47
Umuspo 3 3.67 1.67 1.45 0.03 9.84 2.00 1.00 43.75 25.36
TIS 87/0087 10.11 1.33 3.22 0.80 10.40 0.00 0.00 40.49 23.73
Total 6.12 2.56 2.78 0.49 9.53 0.88 1.14 44.02 39.47
LSD (P< 0.05) NS 3.26 5.14 1.10 7.75 NS NS 7.15 16.97
MRN = Marketable root number, URN = Unmarketable root number, MRW = Marketable root weight, URW =
Unmarketable root weight
Pearson Correlation Coefficients (γ) for Yield Parameters of 68 Sweet Potato Progenies
The Pearson correlation coefficients (γ) for the storage root parameters for 68 genotypes were
shown in Table 4. Results presented in table 4 indicated that total storage root yield was highly
significant (P<0.01) and positively correlated with marketable root number (r=0.571),
unmarketable root number (r=0.301), marketable root weight (r=0.793) and unmarketable
root weight (r=0.4812), respectively. Storage root yield had a negative relationship with both
dry matter and starch (r = -0.009 and -0.102, respectively). Cylas incidence (r=0.175) had a
significant (P<0.05) and positive relationship with storage root yield, whereas Cylas severity
had a positive relationship with storage root yield (r=0.131). Correlation studies help breeders
understand the mutual component characteristics on which to base selection for genetic
improvement. Ulasi et al. (2021) found a significant and positive relationship between total
storage root yield and marketable storage root number and marketable fresh storage root
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
weight, which is consistent with the findings of this study. Also, the findings of Yohannes et al.
(2010) which indicated that the total marketable number of roots, as well as the total
unmarketable number of roots, had a positive correlation with total storage root yield is in
agreement with the result from this study. Tesfaye (2007) discovered a link between total
storage root yield and marketable storage root yield. According to Islam et al. (2002), traits
with negative correlation coefficients could not be improved with total storage root yield in a
positive direction.
Table 4: Pearson correlation coefficients (γ) for the storage root parameters of 68
sweet potato progenies
MRN URN MRW URW Yield Cylas
incidence
Cylas
severity
Dry
matter
Starch
MRN
URN 0.415**
MRW 0.769** 0.507**
URW 0.662** 0.649** 0.805**
Yield 0.571** 0.301** 0.793** 0.481**
Cylas incidence -0.040 0.138* -0.011 0.013 0.175*
Cylas severity -0.062 0.129 0.001 0.031 0.131 0.770**
Dry matter 0.005 -0.114 -0.021 -0.003 -0.009 0.065 0.020
Starch 0.020 -0.171* -0.109 -0.126 -0.102 0.099 0.141* -0.024
**. Correlation is significant at the 0.01 level (2-tailed).
*. Correlation is significant at the 0.05 level (2-tailed).
MRN = Marketable root number, URN = Unmarketable root number, MRW = Marketable root weight, URW =
Unmarketable root weight
Principal Component Analysis of 68 Sweet Potato Progenies.
The principal component (PC) analysis had four main principal component axes with
eigenvalues up to 1.0, resulting in a cumulative variance of 81.64% (Table 5). Principal
component one (PC1) contributed 38.32% of total variability with an eigenvalue of 3.49, while
PC2 contributed 20.46% of total variability with an eigenvalue of 1.84. Principal component
one (PC3) contributed 11.48% of total variability with an eigen value of 1.03, while PC4
contributed 211.36% of total variability among the 68 sweet potato genotypes with an eigen
value of 1.02. Table 5 showed that in PC1, the traits that accounted for most of the 38.32%
observed variability among the 68 genotypes were number of marketable roots (0.824),
unmarketable storage root number (0.685), weight of marketable roots (0.945), weight of
unmarketable roots (0.876), and yield (0.773). In PC2, the traits that accounted for most of the
20.46% observed variability among the 68 genotypes were Cylas incidence (0.926 vector
loading) and Cylas severity (0.928). In PC3, the traits that accounted for the majority of the
11.48% observed variability among the 68 genotypes included dry matter with a vector loading
of 0.82. Starch with a vector loading of 0.85 was the trait that accounted for most of the 11.36%
observed variability among the 68 genotypes in PC4. According to Afuape et al. (2011), PCA is
a technique for determining which plant traits are most responsible for the observed variation
within a collection of genotypes. In this study, four main principal components identified
accounted for 81.64% of the cumulative variance, which is consistent with findings of Ulasi et
al. (2021), who reported a cumulative variance of 73.10% for the three axes in the evaluation
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of thirty-six sweet potato genotypes. According to the findings of Koussao et al. (2014), four
main principal components (PC) were identified, accounting for 67.22% of the total variation
between accessions. Placide et al. (2015) used PCA to investigate the variability of 54 sweet
potato genotypes and discovered a cumulative variance of 77.83% from the first seven major
component axes.
Table 5: Principal component analysis of 68 sweet potato progenies.
Component
1 2 3 4
MRN 0.824 -0.143 0.189 0.212
URN 0.685 0.083 -0.365 -0.163
MRW 0.945 -0.098 0.099 0.066
URW 0.876 -0.073 -0.036 -0.035
Yield 0.773 0.103 0.156 0.040
Cylas incidence 0.102 0.926 -0.031 -0.107
Cylas severity 0.091 0.928 -0.072 -0.042
Dry matter -0.037 0.076 0.852 -0.452
Starch -0.151 0.254 0.311 0.853
Total 3.449 1.842 1.033 1.023
% Of Variance 38.328 20.469 11.481 11.366
Cumulative % 38.328 58.796 70.277 81.643
MRN = Marketable root number, URN = Unmarketable root number, MRW = Marketable root weight, URW =
Unmarketable root weight
CONCLUSION
The results from this study indicated that most of the yield and yield contributing traits;
marketable root weight, unmarketable root weight, yield, dry matter, and starch contents
during both cropping seasons differed significantly (P< 0.05) among the F1 progenies of the
sweet potato genotypes. Also, this study revealed that marketable root number, unmarketable
root number, Cylas incidence and Cylas severity did not vary significantly. During the first-year
trial, LPC/13 produced the highest yield of 22.50 tons/ha while LPC/14 produced the highest
yield of 22.56 tons/ha in the second-year trial. In the first-year trial, twelve (12) genotypes
produced storage root yields greater than 13 tons/ha, which higher than the yield of both
checks used in the study, while in the second-year trial, revealed that eleven (11) genotypes
produced storage root yields greater than 13 tons/ha, which higher than the yield of both
checks used in the study. Based on these results, the storage root yields of the sweet potato
genotypes were consistent in both years. Results from this study showed that fourteen (14)
genotypes had no observable sweet potato weevil damage, whereas sixteen (16) genotypes had
minimal sweet potato weevil damage. Fifteen (15) genotypes recorded moderate damage
caused by sweet potato weevil attack. LPC/45 had the highest starch content, 68.79 mg100g-1
and twenty-one (21) genotypes recorded starch content above 50mg100-1. LPC/36 recorded
the highest dry matter (49.90 %). Total storage root yield was highly significant (P<0.01) and
positively correlated with marketable root number (r=0.571), unmarketable root number
(r=0.301), marketable root weight (r=0.793) and unmarketable root weight (r=0.481),
respectively. This indicated that sweet potato farmers aiming to higher yield should consider
number of marketable roots, weight of marketable roots and total storage root yields as
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Harry, G. I., Ulasi, J. I., & Rosemary, K. E. (2023). Field Trail of F1 Population of Elite Sweet Potato (Ipomoea Batatas (L.) Lam) For Yield and Yield
Related Traits in Humid Rainforest of Umudike, Southeastern Nigeria. European Journal of Applied Sciences, Vol - 11(3). 555-568.
URL: http://dx.doi.org/10.14738/aivp.113.14938
important traits in selection. The agronomic performance of these F1 progenies indicated that
these elite sweet potatoes are suitably adapted to humid rain forest zone of Nigeria. From this
study, LPC/13 and LPC/14 which produced the highest yield in both years could be included
into the list of high-performing sweet potato genotypes well adapted this environment for mass
production. Consequently, these sweet potato genotypes are recommended to be incorporated
into sweet potato breeding program for the development of high-yielding and resistant
genotypes.
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