Effects of Sett Size and Spacing on Tuber Yield of White Guinea Yam (Dioscorea rotundata) in the Rainforest and Savanna Zones of Nigeria

1984 ◽  
Vol 20 (1) ◽  
pp. 53-57 ◽  
Author(s):  
G. O. Kayode
Keyword(s):  
Tuber Yield ◽  
Field Studies ◽  
Dioscorea Rotundata ◽  
Forest Zone ◽  
Optimum Spacing ◽  
Guinea Yam ◽  
Savanna Zone

SUMMARYField studies designed to investigate the effects of sett size and spacing on tuber yield of white Guinea yam were conducted in three locations over a two year period in the rainforest and savanna zones of Nigeria. Sett weights larger than 400 g could be used for maximum tuber yields in both forest and savanna zones. Spacing had no significant effects on tuber yield in the savanna zone, but optimum spacing has yet to be identified in the forest zone.

scholarly journals Identification of Quantitative Trait Nucleotides and Candidate Genes for Tuber Yield and Mosaic Virus Tolerance in an Elite Population of White Guinea Yam (Dioscorea Rotundata) Using Genome-Wide Association Scan

2021 ◽  
Author(s):  
Paterne AGRE ◽  
Prince E. Norman ◽  
Robert Asiedu ◽  
Asrat Asfaw
Keyword(s):  
Mosaic Virus ◽  
Candidate Genes ◽  
Quantitative Trait ◽  
Tuber Yield ◽  
Genome Wide Association ◽  
Dioscorea Rotundata ◽  
Genome Wide ◽  
Severity Scores ◽  
Virus Tolerance ◽  
Guinea Yam

Abstract Background Improvement of tuber yield and tolerance to viruses are priority objectives in white Guinea yam breeding programs. However, phenotypic selection for these traits is quite challenging due to phenotypic plasticity and cumbersome screening of phenotypic-induced variations. This study assessed quantitative trait nucleotides (QTNs) and the underlying candidate genes related to tuber yield per plant (TYP) and yam mosaic virus (YMV) tolerance in a panel of 406 white Guinea yam (Dioscorea rotundata) breeding lines using a genome-wide association study (GWAS). Results Population structure analysis using 5,581 SNPs differentiated the 406 genotypes into four distinct sub-groups (K = 4). Marker-trait association (MTA) analysis using the generalized linear model identified ten QTN regions significant for TYP and five for YMV. We identified variants responsible for predicting higher yield and low virus severity scores in the breeding panel through the marker-effect prediction. Gene annotation for the significant SNP loci identified several essential putative genes associated with the growth and development of tuber yield and those that code for tolerance to mosaic virus. Conclusion Our results provide valuable insight for marker validation and deployment for tuber yield and mosaic virus tolerance in white yam breeding. The information on SNP variants and genes from the present study would fast-track the application of genomics-informed selection decisions in breeding white Guinea yam for rapid introgression of the targeted traits.

scholarly journals Comparative Effect of Poultry and Swine Manures on the Performance of White Guinea Yam (Dioscorea rotundata Poir) in an Ultisols Environment

2018 ◽  
Vol 10 (4) ◽  
pp. 516-521
Author(s):  
Nwabueze C. NWAOGUALA ◽  
Kolawole E. LAW-OGBOMO
Keyword(s):  
Leaf Area Index ◽  
Tuber Yield ◽  
Poultry Manure ◽  
Application Rate ◽  
Tuber Weight ◽  
Dioscorea Rotundata ◽  
Area Index ◽  
Application Rates ◽  
Guinea Yam ◽  
Better Than

White Guinea yam (Dioscorea rotundata Poir) is an important staple food in a number of African countries, including Nigeria and Ghana. However, the tuber yield in these areas is below its potential yield. The most probably constraint to low tuber yield is the low soil nutrient status. A field trial was conducted at the Experimental Farm of the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City, Nigeria, between April and November 2016 and 2017, to evaluate the effect of poultry and swine manures on the growth and tuber yield of white Guinea yam (D. rotundata) in an ultisols environment. The trial was laid out in a 2 × 3 split plot arrangement fitted into randomized complete block design with three replicates. The main plots were organic fertilizers (poultry and swine manures) and the sub-plots were represented by three rates (0, 300 and 450 kg N ha-1) of application. Data collection on growth characters were on vine length (cm), vine girth (cm), number of nodes, number of leaves and leaf area index. At harvest, tuber length (cm), tuber girth (cm), number of tubers per plant, tuber weight and tuber yield (t ha-1) were also evaluated. The results showed that growth and yield variables varied significantly (p < 0.05) with organic fertilizer types and application rates. Poultry manure treated plants produced higher (p < 0.05) number of nodes and leaves than swine manure treated plants. Application rates of 300 and 450 kg N ha-1 of poultry manure significantly increased vine length, vine girth, number of nodes and leaves as well as leaf area index. Tuber weight and yield were higher in plants treated with poultry manure with the application rates of 300 and 450 kg N ha-1 performed better than control in 2016, while the application rate of 300 kg N ha-1 had the highest tuber weight and yield in 2017. Application rates of 300 and 450 kg N ha-1 performed better than the control (0 kg N ha-1) in 2016. However, in 2017, application rate of 300 kg Nha-1 had the highest tuber weight and yield. The present study suggests that poultry manure at application rate of 300 kg N ha-1 could be adopted by white Guinea yam farmers for high productivity of the crop under intense and continuous cropping in humid ultisols environment.

DORMANCY IN YAMS

2001 ◽  
Vol 37 (2) ◽  
pp. 147-181 ◽  
Author(s):  
P. Q. CRAUFURD ◽  
R. J. SUMMERFIELD ◽  
R. ASIEDU ◽  
P. V. VARA PRASAD
Keyword(s):  
West Africa ◽  
Growing Season ◽  
Tuber Initiation ◽  
Adaptive Mechanism ◽  
Tuber Dormancy ◽  
Dioscorea Rotundata ◽  
Dormant Period ◽  
Forest Zone ◽  
Staple Foods ◽  
Guinea Yam

The tubers of yam, principally those of Dioscorea rotundata (white Guinea yam) and D. alata (water or greater yam), are important staple foods and sources of carbohydrate in West Africa. Yams are grown in diverse environments – from the high-rainfall forest zone on the coast to the seasonally arid savannas of West Africa, that is in situations in which the duration and the timing of the onset of the growing season vary appreciably. Dormancy in both underground and aerial tubers of the Dioscoreaceae is an important adaptive mechanism that helps to maintain organoleptic quality during storage and also ensures that tubers germinate at the start of the growing season. Plant breeders are especially keen to manipulate the duration of the dormant period in order to synchronize growth periods and, therefore, to produce more than one generation per year. The control of tuber dormancy, however, is poorly understood. This review examines critically those factors that affect tuber initiation, dormancy and sprouting, and makes recommendations for future priorities in research.

scholarly journals Effects of plant density and npk application on the growth and yield of white guinea yam (Dioscorea rotundata Poir) in a forest zone of Nigeria

2014 ◽  
Vol 14 (66) ◽  
pp. 9404-9417
Author(s):  
KE Law-Ogbomo ◽  
◽  
AU Osaigbovo
Keyword(s):  
Tuber Yield ◽  
Plant Density ◽  
Agronomic Traits ◽  
Block Design ◽  
Application Rate ◽  
Growth And Yield ◽  
Dioscorea Rotundata ◽  
Forest Zone ◽  
Area Index ◽  
Plant Densities

Studies were conducted at Evboneka, Edo State, Nigeria in a forest zone to examine the effect of increasing plant population and NPK application on the growth and tuber yield of Dioscorea rotundata (Poir) cv “Obiaoturugo”. This study involved three trials. The first was conducted in 2010 involving five plant densities (10000, 13333, 17778, 20000 and 266667 plants per hectare (pph)) laid in a randomized complete block design (RCBD) and replicated four times. The second trial was conducted in 2010 involving five NPK application rate (0, 100, 200, 300 and 400 kg NPK 15:15:15 ha-1) using RCBD and replicated three times. In the third trial, the best three plant densities (10000, 13333 and 17778 pph) from the first trial were re-evaluated with the best two NPK application rates (200 and 300 kg NPK ha-1) and control (0 kg ha-1) from the second trial using a 3 x 3 factorial arrangement fitted into RCBD with three replicates. Results from the plant density trial revealed that increasing plant density significantly resulted in increased fresh tuber yield and decreased in number of tuber per stand, tuber size, % unmarketable tuber and multiplication ratio (MR). Based on MR, the best tuber yield was produced from 10000 pph, followed by 13333 and 17778, which were statistically comparable. Results from the fertilizer trial showed that the application of 300 kg ha-1 had the highest tuber yield (19.16 t ha-1 ) statistically similar to 200 kg ha-1 (19.12 t ha-1). There was no significant interaction effect on agronomic traits assessed as both factors acted independently on yam plants. Increasing plant density and NPK application rate resulted in increased degree of foliation and leaf area index (LAI). These parameters imparted higher photosynthetic capacity and translocation leading to higher total dry matter production and tuber yield. A plant density of 10000 pph and 300 kg ha-1 could be most profitable and also bring about a considerable increase in growth and tuber yield of yam.

scholarly journals Impact assessment of the biological control of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), by the introduced parasitoid Epidinocarsis lopezi (De Santis) (Hymenoptera: Encyrtidae)

1989 ◽  
Vol 79 (4) ◽  
pp. 579-594 ◽  
Author(s):  
P. Neuenschwander ◽  
W. N. O Hammond ◽  
A. P. Gutierrez ◽  
A. R. Cudjoe ◽  
R. Adjakloe ◽  
...  
Keyword(s):  
Biological Control ◽  
Tuber Yield ◽  
Significant Proportion ◽  
Phenacoccus Manihoti ◽  
Epidinocarsis Lopezi ◽  
Forest Zone ◽  
Forest Region ◽  
Forest Regions ◽  
The Impact ◽  
Savanna Zone

AbstractThe impact of Phenacoccus manihoti Matile-Ferrero on growth and tuber yield of cassava, and the results of its biological control by the exotic parasitoid Epidinocarsis lopezi (De Santis) were investigated in a survey of 60 farmers' fields in Ghana and Ivory Coast over an area of 180 000 km2 of the savana and forest ecosystems. Twenty-nine variables associated with plant growth, agronomic and environmental factors, and insect populations were recorded. Densities of P. manihoti were closely correlated with stunting of the cassava shoot tips and, less so, with the rate of stunting early in the growing season. With increasing mealybug infestations, average harvest indices declined and populations of E. lopezi and of indigenous coccinellids increased, but parasitoids were found at lower host levels than were predators. The length of time E. lopezi had been present in an area was the most important factor influencing mealybug densities. Thus, P. manihoti populations were significantly lower where E. lopezi had been present for more than half the planting season than in areas where E. lopezi was lacking or had been only recently introduced. A significant proportion of the farmers in the savanna zone, where P. manihoti populations were much higher than in the forest zone, had observed this decline due to E. lopezi. Tuber yield losses due to P. manihoti in the absence of E. lopezi were tentatively estimated at 463 g/plant in the savanna zone. No significant effect was found in the forest region. When E. lopezi was present, average P. manihoti damage scores were reduced significantly, both in the savanna and forest regions. The increase in yields was 228g/plant or about 2.48 t/ha in the savanna region.

scholarly journals Identification of quantitative trait nucleotides and candidate genes for tuber yield and mosaic virus tolerance in an elite population of white guinea yam (Dioscorea rotundata) using genome-wide association scan

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Paterne A. Agre ◽  
Prince E. Norman ◽  
Robert Asiedu ◽  
Asrat Asfaw
Keyword(s):  
Mosaic Virus ◽  
Candidate Genes ◽  
Quantitative Trait ◽  
Tuber Yield ◽  
Genome Wide Association ◽  
Dioscorea Rotundata ◽  
Genome Wide ◽  
Severity Scores ◽  
Virus Tolerance ◽  
Guinea Yam

Abstract Background Improvement of tuber yield and tolerance to viruses are priority objectives in white Guinea yam breeding programs. However, phenotypic selection for these traits is quite challenging due to phenotypic plasticity and cumbersome screening of phenotypic-induced variations. This study assessed quantitative trait nucleotides (QTNs) and the underlying candidate genes related to tuber yield per plant (TYP) and yam mosaic virus (YMV) tolerance in a panel of 406 white Guinea yam (Dioscorea rotundata) breeding lines using a genome-wide association study (GWAS). Results Population structure analysis using 5,581 SNPs differentiated the 406 genotypes into seven distinct sub-groups based delta K. Marker-trait association (MTA) analysis using the multi-locus linear model (mrMLM) identified seventeen QTN regions significant for TYP and five for YMV with various effects. The seveteen QTNs were detected on nine chromosomes, while the five QTNs were identified on five chromosomes. We identified variants responsible for predicting higher yield and low virus severity scores in the breeding panel through the marker-effect prediction. Gene annotation for the significant SNP loci identified several essential putative genes associated with the growth and development of tuber yield and those that code for tolerance to mosaic virus. Conclusion Application of different multi-locus models of GWAS identified 22 QTNs. Our results provide valuable insight for marker validation and deployment for tuber yield and mosaic virus tolerance in white yam breeding. The information on SNP variants and genes from the present study would fast-track the application of genomics-informed selection decisions in breeding white Guinea yam for rapid introgression of the targeted traits through markers validation.

scholarly journals Effect of leaf thinning on shoot growth and tuber yield of white Guinea yam

2021 ◽  
pp. 1-9
Author(s):  
Kohtaro Iseki ◽  
Olajumoke Olaleye ◽  
Ryo Matsumoto
Keyword(s):  
Shoot Growth ◽  
Tuber Yield ◽  
Guinea Yam
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