







































 
 
 

 

52 
 

Agriculture and Food Sciences Research 
Vol. 5, No. 2, 52-56, 2018 

ISSN(E) 2411-6653 / ISSN(P) 2518-0193 
DOI: 10.20448/journal.512.2018.52.52.56 

 

 
 
 
Growth and Yield Response of Sweet Potato (Ipomoea batatas L. Lam) Varieties to 
Lowland Agro-Ecology of Raya Azebo, Ethiopia 

 
Haileslassie Gebremeskel1

     

Kedir Jaleto2     

Wakuma Biratu3      

Haile Abebe4     

 

 
( Corresponding Author) 

 
1,2,3,4Department of Horticulture, Ethiopian Institute of Agricultural Research, Mehoni Agricultural Research 
Center, Maichew, Ethiopia 

 

 
Abstract 

Evaluation activity was conducted using four sweet potato varieties (Awassa-83, Kabode, Kulfo 
and Tulla) at Mehoni Agricultural Research Center (MeARC) during 2015 and 2016 testing 
years. The treatments were arranged in randomized complete block design with three 
replications. The analysis of variance table indicated the existence of significant variation among 
sweet potato varieties for all the characters considered in this study in both 2015 and 2016 testing 
years except number of nodes/plant and tuber diameter during 2016 cropping year. From this 
investigation, significantly higher marketable yield (29.20 t ha-1) and total yield (33.42 t ha-1) 
were obtained from Kulfo variety. Overall, Kulfo was found well adapted and produced higher 
yield in the testing location. Hence, it is possible to use Kulfo variety for the production of 
marketable and total tuber yield by farmers and investors in Raya Azebo, Ethiopia. 

 
Keywords: Sweet potato, Growth, Tuber diameter, Marketable yield, Total yield. 

 
Citation | Haileslassie Gebremeskel; Kedir Jaleto; Wakuma Biratu; 
Haile Abebe (2018). Growth and Yield Response of Sweet Potato 
(Ipomoea batatas L. Lam) Varieties to Lowland Agro-Ecology of 
Raya Azebo, Ethiopia. Agriculture and Food Sciences Research, 5(2): 
52-56. 
History:  
Received: 5 March 2018 
Revised: 7 April 2018 
Accepted: 9 April 2018 
Published: 12 April 2018 
Licensed: This work is licensed under a Creative Commons 

Attribution 3.0 License  
Publisher: Asian Online Journal Publishing Group 
 

Contribution/Acknowledgement: Our especial thank also go to Tewodros 
Abrha and Halefom Hailu for their help in field works. Our sincere thanks also 
go to all who made input for this study. 
Funding: The authors would like to acknowledge Mehoni Agricultural 
Research Center (MeARC) and Roots, Vegetables and Fruits Research Project 
for providing all the facilities and financial support during the entire 
experimentation. 
Competing Interests: The authors declare that they have no conflict of 
interests. 
Transparency: The authors confirm that the manuscript is an honest, 
accurate, and transparent account of the study was reported; that no vital 
features of the study have been omitted; and that any discrepancies from the 
study as planned have been explained. 
Ethical: This study follows all ethical practices during writing.   

 

 

Contents 
1. Introduction ...................................................................................................................................................................................... 53 
2. Material and Methods ..................................................................................................................................................................... 53 
3. Result and Discussion ..................................................................................................................................................................... 53 
4. Conclusion ......................................................................................................................................................................................... 55 
References .............................................................................................................................................................................................. 55 
 

 

 

 

 

 

http://crossmark.crossref.org/dialog/?doi=10.20448/journal.512.2018.52.52.56&domain=pdf&date_stamp=2017-01-14
http://creativecommons.org/licenses/by/3.0/
http://creativecommons.org/licenses/by/3.0/
https://orcid.org/orcid-search/quick-search?searchQuery=Haileslassie%20Gebremeskel
https://orcid.org/orcid-search/quick-search?searchQuery=Kedir%20Jaleto
https://orcid.org/orcid-search/quick-search?searchQuery=Wakuma%20Biratu
https://orcid.org/orcid-search/quick-search?searchQuery=Haile%20Abebe


Agriculture and Food Sciences Research, 2018, 5(2): 52-56 

53 
 

 

1. Introduction 
Sweet potato (Ipomoea batatas L. Lam); 2n=6x=90) is a herbaceous dicotyledonous plant with creeping, 

perennial vines and adventitious roots. It belongs to family Convovulaceae (morning glory flowers) and is hexaploid 
which is usually considered the only Ipomoea species of economic importance [1]; [2]; [3]. Sweet potato is 
originated from South America and it is cultivated in China, Uganda, Nigeria, Indonesia, Tanzania, Vietnam, India 
and United States [4].  
Sweet potato is highly heterozygous cross pollinated crop in which many of the traits show continuous variation. It 
is known for its resistance to drought, vigorous early growth and low input requirements [5]; [6]. Globally sweet 
potato is the seventh most important food crop after wheat, rice, maize, potato, barley and cassava and second most 
important root and tuber crop in the world after potato [3] however, in Sub-Saharan Africa sweet potato is the 
third most important tuber crop after cassava and yam [7]. Throughout the world 107.6 million tons of sweet 
potatoes are produced [8] whereas the world average storage root yield of sweet potato has been estimated to be 
14.8 t ha-1 [9]. 

Sweet potato has large, starchy, sweet-tasting and tuberous roots which adapts to tropical and warm 
temperate regions [10]. High dry matter content is the main characteristic preferred by consumers and processors 
of sweet potato [11]. Storage-roots (root tubers) of sweet potato contain 30% dry matter that 70% of it starch, 5% 
sugar and 5% protein with vitamin A, C and B. Especially orange colored sweet potatoes contain vitamin A (ßeta 
carotene) and vitamin C [12].  It is a relatively drought tolerant crop providing the highest dry matter content for 
human consumption [11]. Sweet potato provides comparatively high calorie at 152 MJ ha-1 day-1. Other crops such 
as cassava, wheat, rice and maize provide 121, 135, 151 and 159 MJ ha-1 day-1 calories, respectively [13]; [2].  

In Ethiopia, among the most important root and tuber crops, sweet potato is one of the major traditional food 
crops [14]. It is cultivated in Ethiopia mostly for human consumption and as animal feed. It ranks third after Enset 
(Ensete ventricosum (Welw.) Cheesman,) and potato (Solanum tuberosum L.) as the most important root crop 
produced in the country [15]. The Ethiopian national average storage root yield of sweet potato is 8 t ha-1 while 
experimental storage roots yields ranging between 30 and 73 t ha-1 [16]; [17]. According to those authors yields 
obtained in Ethiopia are generally low; however, there is good potential for the crop since climatic and soil factors 
are largely favourable.  

It is an attractive crop among Ethiopian farmers due to its high productivity, universal uses, high caloric 
content and good taste, tolerant to adverse environmental conditions such as drought, low soil fertility, high 
rainfall and it requires very little labor and care compared to other crops [5]. According to these authors in 
Ethiopian, sweet potato is commonly grown by farmers in complex, mixed cropping systems where they normally 
plant several varieties with different characteristics like that of yield, maturity, root size, shape and disease and 
drought tolerance. Farmers may use the vines left in the fields to improve soil fertility and the crop is used in crop 
rotation. 

Despite the various advantages of sweet potato have, research work on adaptability of the plant is very limited. 
In general, lack of information on performance evaluation and appropriate agronomic practices is considered to be 
among the major hindrance to embark on higher production and wisely utilization of this valuable plant in the 
country. Thus, it is necessary to evaluate the adaptability that would enable to maximize growth and yield in order 
to diversify and popularize this economically important plant in study area. Therefore, the objective of this study 
was to study the growth and yield response of sweet potato varieties to lowland agro-ecology of Raya Azebo. 
 

2. Material and Methods 
Five months old sweet potato mother plant introduced from Hawassa Agricultural Research Center (HARC) 

was used as a planting material for this experiment. The experiment was carried out at Mehoni Agricultural 
Research Center (MeARC), Ethiopia in 2015 and 2016 cropping season. The center is situated at about 678 km 
north of the Addis Ababa. Geographically it is located at 12° 41'50'' North latitude and 39° 42'08'' East longitude 
with an altitude of 1578 m.a.s.l. The site receives mean annual rainfall of 430-750 mm with an average minimum 
and maximum temperature of 18 and 25°C, respectively. The soil textural class of the experimental area is clay 
loam (Vertisol) with pH of 7.9. 

The experiment consisted of four sweet potato varieties (Awassa-83, Kabode, Kulfo and Tulla) and it was 
arranged in randomized complete block design (RCBD) with three replications according to Gomez and Gomez 
[18]. Thus, there were four treatments in each replication. The space between rows and plants was 75x30 cm 
having a plot size of 4.50 x 3.60 m (16.20 m2) and 72 plants per plot will be considered. The space between 
replications and plots will be 1.5 m and 1 m, respectively. Plants in the four middle rows out of the six rows per 
plot were constitute the net plot to be used as the sampling units. Eight plants from the middle rows were taken for 
sampling and data analysis. All appropriate agronomic practices such as weeding, watering and hoeing were 
conducted manually at the experimental field.  

Data on emergence percentage, plant height, number of nodes/plant, internodes length, tuber length, tuber 
diameter, marketable yield/ha, unmarketable yield/ha and total tuber yield/ha were recorded when yellowing and 
falling of leaves and also cracking of the soil was observed in the experimental plots. Statistical analysis of 
experimental data was subjected to analysis of variance (ANOVA) using SAS PROC GLM (2002) at P<0.05. 
Differences between means were evaluated using Least Significant Difference (LSD) Test at P<0.05. 
 

3. Result and Discussion  
3.1. Variation in Growth and Yield Characters of Sweet Potato  

Mean square from analysis of variance table for all the traits tested for two respective years are summarized 
Table 1, 2 and 3. The performance of all tested varieties were found statistically different (P<0.05) in internode 
length and tuber length, highly significant (P<0.01) in number of nodes/plant and very highly significant 
(P<0.001) in emergence percentage, plant height, tuber diameter, marketable yield, unmarketable yield and total 
yield during 2015 cropping year. However in 2016, number of nodes/plant and tuber diameter did not significantly 
influenced (P>0.05) by varietal difference. Whereas emergence percentage and plant height were significantly 



Agriculture and Food Sciences Research, 2018, 5(2): 52-56 

54 
 

 

affected (P<0.05) by sweet potato variety; which however, highly significant influence (P<0.01) was found in 
internodes length and tuber length and very highly significant (P<0.001) in marketable yield, unmarketable yield 
and total tuber yield of sweet potato varieties. This implies that the different genotypes were exerted significant 
influence on the growth and yield characters of sweet potato. 
 

Table-1. Mean square of growth and yield response of sweet potato during 2015 and 2016 testing years 

Source of 
variation 

Degree of 
freedom 

Emergence percentage Plant height(cm) Number of nodes/plant 

2015 2016 2015 2016 2015 2016 

Replication 2 48.08 10.76 0.002 0.01 9.59 14.07 
Variety 3 820.81*** 141.24* 0.068*** 0.05* 95.48** 15.99ns 
Error 6 16.51 21.48 0.002 0.01 5.21 14.02 

CV (%) 5.44 4.99 4.19 6.18 5.52 8.97 
     Note: *= Significant at P< 0.05; ** =Significant at P<0.01 and ***= Significant at P< 0.001 probability level. CV= Coefficient of variation  
 

Table-2. Mean square of growth and yield response of sweet potato during 2015 and 2016 testing years 

Source of 
variation 

Degree of 
freedom 

Internode length(cm) Tuber length(cm) Tuber diameter(cm) 

2015 2016 2015 2016 2015 2016 

Replication 2 0.03 0.18 0.49 1.91 0.12 0.13 
Variety 3 0.91* 33.71** 8.16* 54.91** 6.57*** 1.02ns 
Error 6 0.10 0.07 1.09 3.48 0.05 0.40 

CV (%) 5.94 7.95 6.33 8.77 4.18 10.22 
Note: *= Significant at P< 0.05; ** =Significant at P<0.01 and ***= Significant at P< 0.001 probability level. CV= Coefficient of variation 

 
Table-3. Mean square of growth and yield response of sweet potato during 2015 and 2016 testing years 

Source of 
variation 

Degree of 
freedom 

Marketable yield(t ha-1) Unmarketable yield( t ha-1) Total yield(t ha-1) 

2015 2016 2015 2016 2015 2016 

Replication 2 115.10 22.77 0.64 24.89 114.52 176.27 
Variety 3 37526.51*** 31030.70*** 703.51*** 1141.79*** 48299.54*** 46648.58*** 
Error 6 91.92 359.30 13.27 19.57 109.55 206.72 

CV (%) 6.60 12.37 14.93 20.70 6.19 8.30 
Note: ns=not significant at P< 0.05, *= significant at P< 0.05; ** =significant at P<0.01 and *** =significant at P< 0.001 probability level. CV= 
Coefficient of variation 

 

3.2. Performance Variation in Growth and Yield of Sweet Potato  
The mean performances of sweet potato varieties are summarized in Table 4, 5 and 6.  Comparing among the 

tested varieties the highest emergence percentage (98.61%) was found at variety Kabode during 2016 testing year. 
While emergence percentage (94.91% and 94.41%) recorded at Kulfo and Tulla varieties, respectively were 
statistically at par with Kabode during the same testing year. However, the lowest emergence percentage (50.31%) 
was obtained at Tulla variety when the experiment was conducted in 2015 cropping year.  

The highest overall mean emergence percentage (90.46%) was recorded at Kabode whereas the lowest value 
(72.61%) was recorded at Tulla variety. Significantly higher plant height (1.74 cm) and number of nodes/plant 
(48.67) were obtained from Awassa-83 variety during 2016 and 2015 cropping year, respectively; which however, 
significantly lower value (1.02 cm) and 35.02 plant height and number of nodes/plant were recorded at variety 
Awassa-83 and Kabode varieties during 2015 testing year. 

Kabode produced significantly higher internode length (5.65 cm) and tuber length (26.33 cm) during 2015 and 
2016 cropping season; respectively. However, internode length obtained from Kabode variety in 2015 was not 
statistically different with the value obtained from Kulfo (5.46 cm) and Tulla (5.39 cm) varieties. On the other hand, 
the lowest internode length (2.92 cm) and tuber length (14.03 cm) were found at Kabode and Awassa-83 varieties 
when the experiment was carried out during 2016 and 2015, respectively. This result in harmony with the findings 
of Teshome, et al. [19]; Yahay, et al. [20] in sweet potato. 

Tuber diameter was significantly influenced in the first year; which however, it did not significantly affected by 
varietal difference in the second testing year. Even though there was no significant effect on tuber diameter in the 
second cropping year Kulfo produced slightly higher tuber diameter (6.96 cm) while the lowest value (3.48 cm) 
obtained from Awasssa-83 in 2015 testing year. Similar result with this finding [21] was also reported on sweet 
potato response to fertilizer trial. 

Concerning the yield parameters, all the three yield characters were influenced by varietal difference in both 
testing years. Kulfo produced significantly higher marketable yield (29.20 t ha-1) followed by same variety (26.57 t 
ha-1) in 2015 and 2016 cropping season, respectively. However, the lowest marketable yield (2.16 t ha-1) and (3.21 t 
ha-1) were obtained from Awassa-83 variety while the experiment is implemented during 2015 and 2916, 
respectively. Overall, mean marketable yield varied from 27.98 to 2.68 t ha-1 among the testing genotypes in both 
cropping seasons.  

Unmarketable yield/ha was significantly influenced by genotypic difference in both testing years. The 
maximum unmarketable yield (4.71 t ha-1) was obtained at variety Kulfo along with the testing year of 2016 
followed by (4.22 t ha-1) at the same variety when the research experiment conducted in 2015 testing year; whereas, 
the minimum value (0.30 t ha-1) was obtained at Awassa-83 variety in 2016 cropping  year. The highest sweet 
potato total tuber yield (33.42 t ha-1) was obtained from Kulfo variety in 2015 followed by (31.48 t ha-1) from the 
same variety during 2016; while the lowest total yield (2.58 t ha-1) was obtained from Awassa-83 in 2016 testing 
year. From the mean comparison table Kulfo variety was produced significantly higher (32.45 t ha-1) mean total 
tuber yield. These results are in agreement with findings of Kathabwalika, et al. [22] in sweet potato. 
 
 
 
 



Agriculture and Food Sciences Research, 2018, 5(2): 52-56 

55 
 

 

 Table-4. Mean performance of growth and yield of sweet potato varieties tested at Raya Azebo during 2015 and 2016 
cropping season 

Variety Emergence percentage Plant height (cm) Number of nodes/plant 

2015 2016 Mean 2015 2016 Mean 2015 2016 Mean 

Awassa-83 86.76a 82.87b 84.82 1.02c 1.74a 1.38 48.67a 42.08 45.38 
Kabode 82.31a 98.61a 90.46 1.06bc 1.59ab 1.33 35.02c 42.67 38.85 
Kulfo 79.43a 94.91a 87.17 1.15b 1.41b 1.28 40.00b 38.42 39.21 
Tulla 50.31b 94.91a 72.62 1.36a 1.57ab 1.47 41.67b 43.73 42.70 
LSD (5%) 8.12 9.26  0.10 0.19  4.56 ns  
CV (%) 5.44 4.99  4.19 6.18  5.52 8.97  

Note: Means followed by the same letter with in the same column are not significantly different at 5% level of probability. 
CV=Coefficient of variation, LSD=List significant difference 

 
Table-5. Mean performance of growth and yield of sweet potato varieties tested at Raya Azebo during 2015 and 2016 cropping season 

  Internode length (cm) Tuber length(cm) Tuber diameter (cm) 

2015 2016 Mean 2015 2016 Mean 2015 2016 Mean 

Awassa-83 4.42b 4.06a 4.24 14.03b 23.27a 18.65 3.48c 5.56 4.52 
Kabode 5.65a 2.92b 4.29 17.59a 26.33a 21.96 4.23b 5.83 5.03 
Kulfo 5.46a 3.36b 4.41 17.02a 17.64b 17.33 6.35a 6.96 6.66 
Tulla 5.39a 3.01b 4.20 17.13a 17.79b 17.46 6.39a 6.31 6.35 
LSD (5%) 0.62 0.53  2.09 3.73  0.43 ns  
CV (%) 5.94 7.95  6.33 8.77  4.18 10.22  

   Note: Means followed by the same letter with in the same column are not significantly different at 5% level of probability. 
   CV=Coefficient of variation, LSD=List significant difference 

 
Table-6. Mean performance of growth and yield of sweet potato varieties tested at Raya Azebo during 2015 and 2016 cropping season 

Variety Marketable yield ( t ha-1) Unmarketable yield(t ha-1) Total yield (t ha-1) 

2015 2016 Mean 2015 2016 Mean 2015 2016 Mean 

Awassa-83 2.16d 3.21d 26.83 0.56d 0.30c 4.26 2.71d 2.58d 26.45 
Kabode 11.90c 11.63c 117.64 2.09c 1.05c 15.70 13.99c 12.68c 133.34 
Kulfo 29.20a 26.75a 279.75 4.22a 4.71a 44.63 33.42a 31.48a 324.48 
Tulla 14.66b 19.73b 171.93 2.90b 2.47b 26.86 17.59b 22.53b 200.59 
LSD (5%) 19.09 37.87  7.28 8.84  20.91 28.73  
CV (%) 6.60 12.37  14.93 20.70  6.19 8.30  

Note: Means followed by the same letter with in the same column are not significantly different at 5% level of probability. 
CV=Coefficient of variation, LSD=List significant difference 

 
4. Conclusion  

The analysis of variance table indicated that all agronomic and yield characters had significantly affected by 
sweet potato genotypic difference in the 2015 cropping season; whereas, variety did not exert any significant 
influence on number of nodes/plant and tuber diameter traits. From this experimental study, significantly higher 
mean marketable yield (27.98 t ha-1), unmarketable yield (4.46 t ha-1) and total yield (32.45 t ha-1) were obtained 
from Kulfo variety. Generally, Kulfo was found well performed and produced higher yield in the testing location. 
Likewise, the values obtained in this experiment demonstrated comparable and even higher values in yield 
characters with the different reports. Hence, it is possible to use Kulfo cultivar for the production of marketable and 
total tuber yield in Raya Azebo, Ethiopia. 
 

References 
[1] L. Degrass, The yam a tropical root crop. The technical centre for agricultural and rural cooperation (CTA). London: The Macmillian 

Press, 2000. 
[2] A. I. Abukari, M. W. Shankle, and K. R. Reddy, "Sweetpotato [Ipomoea batatas (L.) Lam.] Response to S-metolachlor and rainfall 

under three temperature regimes," American Journal of Plant Sciences, vol. 6, pp. 702-717, 2015. View at Google Scholar | View at Publisher 
[3] C. Tortoe, "Microbial deterioration of white variety sweet potato (Ipomoea batatas) under different storage structures," 

International Journal of plant Biology, vol. 1, pp. 10-15, 2010.  
[4] P. Milind and S. Monika, "Sweet potato as a super food," International Journal of Research in Ayurveda and Pharmacy, vol. 6, pp. 557-

562, 2015.  
[5] T. Assefa, A. Teshome, T. Engida, and T. Tesfaye, "Summary of progress on orange-fleshed sweet potato research and 

development in Ethiopia," in Proceedings of the 13th ISTRC Symposium, 2007, pp. 728-731. 
[6] T. Engida, E. V. Devakara, and D. Nigussie, "Correlation and path analysis in sweet potato and their implications for clonal 

selection," Journal of Agronomy, vol. 5, pp. 391-395, 2007.  
[7] P. T. Ewell and J. Mutuura, "Sweet potato in the food system of Eastern and Southern Africa. In: F. Ofori and S.K. Hahn (Eds.)," 

presented at the Symposium on Tropical Root Crops in a developing economy. Acta Hort, 1994. 
[8] FAO, World information and early warning system on plant genetic resources. Rome: Food and Agriculture Organization of the United 

Nations, 2009. 
[9] FAO, Production year book. Rome: Food and Agricultural Organization, 2000. 
[10] M. Daniel and L. Gobeze, "Sweet potato agronomy research in Ethiopia; summary of past findings and future research directions," 

Agriculture and Food Sciences Research, vol. 3, pp. 1-11, 2016. View at Google Scholar | View at Publisher 
[11] R. Placide, S. Hussein, L. Mark, and G. Daphrose, "Storage root formation, dry matter synthesis, accumulation and genetics in 

sweet potato," Australian Journal of Crop Science, vol. 7, pp. 2054-2061, 2013. View at Google Scholar   
[12] J. A. Woolfe, Sweet potato: An untapped food resource. Cambridge, UK: Cambridge University Press, 1992. 
[13] D. E. Horton and H. Fano. Potato atlas; Atlas of the pomme de terre. Lima: Atlas of the Potato International Potato Center, 1985. 
[14] T. Endale, B. Terefe, D. Mukgeta, and L. Geleta, "Improvement studies on enset and sweet potato," in Proceedings of the Second 

National Horticultural Workshop in Ethiopia, 1-3 Dec.1992. Addis Ababa, Ethiopia, 1994, 1994. 
[15] CSA (Central Statistical Authority), Ethiopian agricultural sample enumeration vol. 146. Federal Democratic Republic of Ethiopia, 

Central Statistical Agency, Addis Ababa, Ethiopia, Statistical Bulletin, 2011. 
[16] A. S. Bhagsari and D. A. Ashley, "Relationship of photosynthesis and harvest index of sweet potato yield," Journal of Horticultural 

Science, vol. 111, pp. 288-293, 1990. View at Google Scholar   
[17] V. S. Varma, K. P. Singh, S. K. Singh, J. R. P. Singh, S. P. Verma, S. Mishra, M. P. Sahu, K. Kumari, and R. Ray, "Two high 

yielding selections of sweet potato," Journal of Root Crops, vol. 20, pp. 15-19, 1994.  

https://scholar.google.com/scholar?hl=en&q=Sweetpotato%20%5bIpomoea%20batatas%20(L.)%20Lam.%5d%20Response%20to%20S-metolachlor%20and%20rainfall%20under%20three%20temperature%20regimes
http://dx.doi.org/10.4236/ajps.2015.65076
https://scholar.google.com/scholar?hl=en&q=Sweet%20potato%20agronomy%20research%20in%20Ethiopia;%20summary%20of%20past%20findings%20and%20future%20research%20directions
http://dx.doi.org/10.20448/journal.512/2016.3.1/512.1.1.11
https://scholar.google.com/scholar?hl=en&q=Storage%20root%20formation,%20dry%20matter%20synthesis,%20accumulation%20and%20genetics%20in%20sweet%20potato
https://scholar.google.com/scholar?hl=en&q=Relationship%20of%20photosynthesis%20and%20harvest%20index%20of%20sweet%20potato%20yield


Agriculture and Food Sciences Research, 2018, 5(2): 52-56 

56 
 

 

[18] K. A. Gomez and A. A. Gomez, Statistical procedures for agricultural research, 2nd ed. New York: John Wiley and Sons, 1984. 
[19] A. Teshome, C. Amenti, and T. Kassaye, "Yield and yield components of sweet potato as influenced by plant density. In Adami 

Tulu Jido Kombolcha District, Central Rift Valley of Ethiopia," American Journal of Experimental Agriculture, vol. 1, pp. 40-48, 2011. 
View at Google Scholar | View at Publisher 

[20] S. U. Yahay, A. M. Saad, S. G. Mohammed, and S. O. Afuape, "Evaluating the performance of improved sweet potato (Ipomoea 
Batatas L. Lam) advanced lines in Kano, Sudan Savanna of Nigeria," International Journal of Agronomy and Agricultural Research, vol. 
7, pp. 52-60, 2015. View at Google Scholar   

[21] F. Uwah, U. L. Undie, N. M. John, and G. O. Ukoha, "Growth and yield response of improved sweet potato (Ipomoea Batatas (L.) 
Lam) varieties to different rates of potassium fertilizer in Calabar, Nigeria," Journal of Agricultural Science, vol. 5, pp. 61-69, 2013. 
View at Google Scholar | View at Publisher 

[22] D. M. Kathabwalika, E. H. C. Chilembwe, V. M. Mwale, D. Kambewa, and J. P. Njoloma, "Plant growth and yield stability of 
orange fleshed sweet potato (Ipomoea Batatas) genotypes in three agro-ecological zones of Malawi," International Research Journal 
of Agricultural Science and Soil Science, vol. 3, pp. 383-392, 2013. View at Google Scholar   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

Asian Online Journal Publishing Group is not responsible or answerable for any loss, damage or liability, etc. caused in relation to/arising out of the use of the content. 
Any queries should be directed to the corresponding author of the article. 
 

https://scholar.google.com/scholar?hl=en&q=Yield%20and%20yield%20components%20of%20sweet%20potato%20as%20influenced%20by%20plant%20density.%20In%20Adami%20Tulu%20Jido%20Kombolcha%20District,%20Central%20Rift%20Valley%20of%20Ethiopia
http://dx.doi.org/10.9734/ajea/2011/173
https://scholar.google.com/scholar?hl=en&q=Evaluating%20the%20performance%20of%20improved%20sweet%20potato%20(Ipomoea%20Batatas%20L.%20Lam)%20advanced%20lines%20in%20Kano,%20Sudan%20Savanna%20of%20Nigeria
https://scholar.google.com/scholar?hl=en&q=Growth%20and%20yield%20response%20of%20improved%20sweet%20potato%20(Ipomoea%20Batatas%20(L.)%20Lam)%20varieties%20to%20different%20rates%20of%20potassium%20fertilizer%20in%20Calabar,%20Nigeria
http://dx.doi.org/10.5539/jas.v5n7p61
https://scholar.google.com/scholar?hl=en&q=Plant%20growth%20and%20yield%20stability%20of%20orange%20fleshed%20sweet%20potato%20(Ipomoea%20Batatas)%20genotypes%20in%20three%20agro-ecological%20zones%20of%20Malawi

