Open Access Original Research Article

Potassium Nutrition and Translocation in Cassava (Manihot esculenta Crantz) Intercropped with Soybean

S. I. Umeh, C. C. Onyeonagu, B. U. Umeh

Journal of Experimental Agriculture International, Page 281-286
DOI: 10.9734/AJEA/2015/7868

Experiment to investigate the effect of potassium nutrition and translocation in cassava (Manihot esculenta Crantz) intercropped with soybean (Glycine max (L) Merril) was conducted at University of Nigeria, Nsukka in a derived savannah location of South Eastern Nigeria. The Effect of application of potassium fertilizer on two varieties of cassava intercropped with six cultivars of soybean was studied. Cassava tuber yield was significantly (P<0.05) affected by their varieties, fertilizer rate and cropping system. An increase in the supply of K+ by fertilization (N0K50 and N45K50) increased K+ accumulation in source leaves and caused increase in cassava tuber yield. The highest tuber yield of 42.0 t ha-1 was obtained with NR 8230 cassava variety intercropped with soybeans cultivars TGX 1894-3E with the application of N0K50, followed by NR 8230 intercropped with Samsoy-2 with N45K50 (40.5 t ha-1).

Open Access Original Research Article

Genetic Diversity of Cassava Mutants, Hybrids and Landraces Using Simple Sequence Repeat Markers

Chepkoech Emmy, Kinyua Miriam, Kiplagat Oliver, Arunga Esther Edith, Kimno Stephen

Journal of Experimental Agriculture International, Page 287-294
DOI: 10.9734/AJEA/2015/7556

Aims: Cassava (Manihot esculenta Crantz) is a crop with largely unexplored and unexplained potentially valuable genetic variability. The knowledge and understanding of the extent of genetic variation of cassava germplasm is important for conservation and improvement.

Objective: The current study was to investigate the genetic divergence of cassava mutants, hybrids and landraces using simple sequence repeat (SSR) markers.

Methodology: Genetic diversity of ten cassava genotypes was determined using 14 SSR markers.

Results: Findings from this study showed that the dendrogram based on UPGMA cluster analysis revealed that SSR data indicated the existence of high divergence among the accessions. The cophenetic matrices obtained showed that SSR data marker type was r = 0.91.

Conclusion: The wider genetic diversity observed using SSR markers would be valuable for efficient management of germplasm and for effective utilization of materials in breeding programmes to produce hybrids of desirable characteristics. The extensive genetic diversity is important to coming generations so that it copes with unpredictable environmental changes and human needs.

Open Access Original Research Article

Adoption Process of Agro-biotechnology Among Researchers in Nigerian Universities and Research Institutes: The Logistics Regression Approach

T. G. Apata

Journal of Experimental Agriculture International, Page 295-305
DOI: 10.9734/AJEA/2015/4679

Aims: Food insecurity in most developing countries was a result of their low/small scale of operation in farming enterprise resulting to low yields. To increase agricultural productivity, biotechnology has been considered as a strong potential to improve agricultural production. This paper examined the biotechnology adoption scenario in Nigeria from the viewpoint of academic researchers.

Study Design: A purposive sampling technique was adopted and the target population was limited to 100 academic biotechnology researchers. 

Methodology: Eighty percent of the researchers came from Universities while 10per centeach was drawn from College of Agriculture and Institute of Agricultural Research respectively. Mean age was 44.5 years; mean teaching/research experience was 7.5 years. Logit model estimates for the study areas showed that the effect of the three independent variables: level of knowledge, level of acceptance and level of transfer of technology were statistically significant at 5% level.

Results: These findings’ revealed that knowledge about an innovation is an indicator of the level of adoption. As the awareness of knowledge increases, it is more likely that there will be a corresponding increase in the level of adoption. The acceptance variable has a positive impact on the decision to adopt biotechnology.

Conclusion: The results of this study indicated that the level of knowledge, acceptance and transfer of technology has direct effect on the level of adoption of biotechnology innovations. Therefore, there is need for policies that will streamline agro-biotechnology programme in a sustainable way for potential users.

Open Access Original Research Article

Genetic Diversity of Dry Bean (Phaseolus vulgaris L.) Accessions of Kenya Using SSR Markers

Nyakio Kithinji Maryrose, Katherine Andrea Steele, Valerie A. P. Palapala

Journal of Experimental Agriculture International, Page 306-319
DOI: 10.9734/AJEA/2015/10284

Aims: To determine the genetic diversity existing within the Kenyan dry bean using SSR markers.

Place and Duration of Study: This study was conducted in Western Kenya and Bangor University, North Wales, between September 2010 and December 2012.

Methodology: Thirty five (35) marketable dry bean samples collected from farmers, market centers as well as seed stockists were subjected to SSR analysis. Data generated was subjected to analysis with the GenAlEx 6.4 software assuming Hardy-Weinberg equilibrium to determine gene diversity index, number of polymorphic loci and alleles, genetic distances, analysis of molecular variance (AMOVA) and principal components analysis (PCA). NYTS-pc 2.1 software was used to construct an unweighted pair group method arithmetic averages (UPGMA) dendogram using the generated similarity coefficients.

Results: Of the 7 SSR primers tested, 5 SSR primers were found to be polymorphic and used to screen the bean samples. The 5 primer combinations generated 49 polymorphic bands in 35 samples. Analysis of molecular variance accredited 8% of the disparity to diversity among the populations while the majority of the diversity (92%), resided within populations. The gene diversity index ranged from 0.1267 in the market population to 0.2377 in the Western province population. The highlands of Eastern province had a gene diversity index of 0.1475 while the dry lands had 0.1991. Cluster analysis segregated the bean samples into 9 clusters.

Conclusion: There exists considerable variation in the dry bean of Kenya that is narrowing. There is need to intensify efforts to broaden the bean variation for sustainability. The population genetics of dry beans of Kenya are a possible guide to future bean breeding and germplasm management in Kenya.  

Open Access Original Research Article

Urea Fertilization: Effects on Growth, Nutrient Uptake and Root Development of the Biodiesel Plant, Castor Bean (Ricinus communis L.)

K. Nahar, W. L. Pan

Journal of Experimental Agriculture International, Page 320-335
DOI: 10.9734/AJEA/2015/12729

An indoor pot culture experiment was conducted in the growth chamber during the period of vegetative growth to evaluate the influence of inorganic nitrogen fertilizer in the form of urea on nutrient uptake, growth and root development of castor bean plant. The Nitrogen Fertilizer treatments imposed in the experiment were: Control (N0), no nitrogen and others at the rate and 60lb N/acre (N1), 90lb N/acre (N2) and 120lb N/acre (N3) respectively. Effect of higher nitrogen concentration indicated considerable increases in castor growth including vegetative growth and the plant components biomass. Elevated nitrogen fertilizer increased height and other morphological and physiological parameters (Leaf and petiole length, intermodal distance, root numbers) including the root, shoot dry wt, root/ shoot ratio, nitrogen  and crude protein content  in plants. Among the plant components, shoot, root dry weight and root shoot ratio had the greatest decrease under N deficiency, while root/shoot carbon ratio increased under N deficiency. No statistical difference was observed with treatments in shoot and root N% and shoot C% in plants although root carbon content was significantly higher with lowest nitrogen level compared to elevated levels. Significant increases of carbon content in plants at N0 showed some tendency of this crop to adjust with lower nitrogen levels. Also no statistical difference was observed in root and shoot N ratio, while the root and shoot carbon ratio was found significant at N0 compared to other treatments. However the concentration of carbon and nitrogen were found higher in shoot than root in all applied treatments. After harvesting the residual nitrogen effect in soil was also found significant with elevated nitrogen level compared with other treatments and control.

Open Access Original Research Article

Transplant and A Change in Plant Density Improve Sweet Maize (Zea mays L.) Yield

J. Rattin, J. P. Valinote, R. Gonzalo, A. Di Benedetto

Journal of Experimental Agriculture International, Page 336-351
DOI: 10.9734/AJEA/2015/13172

Aims: Due the effect of a transplant routine on the maize plant morphology and population stand, the aim of the experiment was to determine the combined effects of three plant densities and the use of transplant on commercial yield for two sweet maize hybrids.

Study Design: Canner (su1) and Butter Sweet (shrunken-2) hybrids were sown, at the same time, by direct seeded or in plastic plug trays (128 cell tray-1) for transplant in middle spring and were grown under 4, 8 and 12 plants m-2 plant densities.

Place and Duration of Study: Experiment was conducted at the INTA Balcarce Experimental Station, Argentina (37° 45′ S, 58° 18′ W) during the 2005-2006 and repeated during 2006-2007 growing seasons.

Methodology: Plants from direct-seeded or transplant were grown at three plant densities under a field environment. A randomized complete factorial design with three blocks was used.

Results: Results showed that transplant increase light interception and radiation use efficiency; the changes in dry weight accumulation in behalf of ears determine an increase in harvest index and yield plant-1. An increase in plant density at 12 plants m-2 would let to obtain an increase in yield ha-1 as well.

Conclusion: Morphological changes which let a change in both crop architecture and yield per ha-1 justify an increase in transplanted sweet maize plant density.

Open Access Original Research Article

Changes in Physicochemical Parameters during Storage of the Inflorescence Sap Derived from Four Coconut (Cocos nucifera L.) Varieties in Côte d’Ivoire

Konan N’guessan Ysidor, Konan Konan Jean-Louis, Konan Brou Roger, Assa Rebecca Rachel, Okoma Djeya Muriel Joelle, Issali Auguste Emmanuel, Biego Godi Henri Marius

Journal of Experimental Agriculture International, Page 352-365
DOI: 10.9734/AJEA/2015/11035

Aim: The study investigated the changes in the main physicochemical parameters of the coconut inflorescence sap derived from MYD, WAT, PB 121+ and PB 113+ varieties during storage.

Place and Duration: Marc Delorme Research Station for coconut, National Agronomic Research Center, Abidjan, Côte d’Ivoire, between March and May, 2013.   

Methodology: The coconut sap was collected from six coconut trees per variety, and then a sample for each variety was constituted by mixing the collected saps. Three samples of the coconut sap from each variety, each collected on a different day (repeated on three days of collection), were stored at 35±2°C. Then 10 parameters were assessed during 120 h (5 days) of storage.

Results: The results showed a significant effect of the storage duration upon the whole parameters. Specifically, important decrease was observed for the total sugars contents (from 16.08 to 0.93 g/100 mL), pH (7.32 to 4.17) and the relative density (1.055 to 1) of the coconut sap samples, without any differentiation between varieties. Also, the total soluble solids and the dry matter contents dropped respectively from 16.31 to 3.82% and 16.47 to 3.09 g/100 g. On the other hand, significant increases were recorded with the total titrable acidity (from 0.26 to 1.85 g/100 g) and the tannins contents (from 5.65 à 13.2 mg/L). Concerning reducing sugars and proteins, partial increasing of their contents (6.60 to 8.29 g/100 mL and 2.34 to 2.84 g/100 mL, respectively) was recorded after 24 hours of storage. The total polyphenols contents reached peaks of 606.84 mg/L to 1316.24 mg/L after 36 h, before decreasing. The WAT differed from the three other varieties with the highest content of total polyphenols and tannins during the 120 hours of storage.

Conclusion: The study evidenced similar changes in the physicochemical traits during 5 days of natural fermentation of the sap of different coconut varieties. The sap remained stable during the earlier 12 hours of storage, but up to 5 days the main nutrients were spoiled.

Open Access Original Research Article

Differential Susceptibility of Some Cowpea Varieties to Field Infestation by Insect Pests in Mubi Region of Sudan Savannah Ecological Zone of Nigeria

G. Y. Luka, G. Abdullahi, A. Shehu

Journal of Experimental Agriculture International, Page 366-373
DOI: 10.9734/AJEA/2015/5780

Aim: To assess the comparative susceptibility of five cowpea varieties to field insect pest infestation.

Study Design: The design used for this study is the Randomized Complete Block Design (RCBD) in which the varieties are the treatments and were replicated four times (4x).

Place and Duration of the Study: Study was carried out in 2011 cropping season (15th July- 15th November) at Adamawa State University Research and Teaching Farm Mubi.

Methodology: Data were collected on days to 50% flowering, days to 50% pod setting, days to 50%pod maturity, mean number of flower producing pods, mean number of surviving pods, mean number of healthy pods produced and the total output per variety/cultivar.

Results: The result revealed that Iron beans had the least degree of susceptibility to field pest infestation and correspondingly recorded the highest yield of 2144g/plot and 1.34 metric ton ha-1. While the highest degree of susceptibility was recorded with Samira which gave a yield of 728g/plot which is equivalent to a projected yield of 0.455 metric tone ha-1. Four species of insects were also found on the plots.

Conclusion: It could be concluded that Iron beans and BOSADP cultivars have demonstrated the least level of susceptibility to field pest infestation, hence relatively more resistant to field pest attack. Therefore, Iron beans and BOSADP due to their low susceptibility to field pest infestations   gave higher yield per plot when compared to other varieties. They could therefore be varieties of choice for cultivation in this locality.

Open Access Original Research Article

Analysis of AFLP Markers for Screening Resistance to Common Bean Roots Rot (Pythium spp.)

Nyakio K. Maryrose, Valerie A. Palapala, Katherine A. Steele, Reuben Otsyula

Journal of Experimental Agriculture International, Page 374-391
DOI: 10.9734/AJEA/2015/9843

Aims: To investigate AFLPs for suitability as potential markers for identification of sources of Pythium resistance in bean genotypes preferred by poor small holder farmers.

Place and Duration of Study: Department of biological sciences Masinde Muliro University of Science and Technology, Kenya and Bangor University, North Wales, United Kingdom, between September 2010 and December 2012.

Methodology: 45 common bean accessions comprising 35 seed samples collected from farmers, market centers, as well as seed stockists and ten common bean lines generated from a conventional breeding program with differential resistance to the pathogen Pythium were subjected to AFLP analysis. Genetic characterization using cluster and principal component analysis were conducted to determine segregating patterns of bean accessions in relation to tolerant and susceptible bean lines. Average genetic distances were calculated and similarity coefficients subjected to unweighted pair group method of arithmetic averages to generate dendograms.

Results: Two informative AFLP primer combinations yielded 194 polymorphic loci. Genetic distance of bean samples from KARI Kakamega had 56 to 414 base pairs with a variability index of 0.63 to 0.90. Combined analysis of bean accessions from KARI breeding program and market class common bean samples revealed a variability index range of 0.62 to 0.90 with 56 to 420 base pairs. PCA contributed about 51.58% on the genetic variation. Cluster analysis of the 10 KARI-Kakamega bean lines revealed that resistant bean varieties were genetically different from the susceptible bean varieties. The dendogram generated revealed four sub-groups and with the exception of Alulu, a mildly resistant cultivar, that segregated alongside resistant cultivars, resistant varieties clustered differently from susceptible cultivars. However, screening with farmers’ germplasm produced a dendogram that revealed a mixture of distinct and relatively non-distinct categorization with regard to resistance. Only resistant cultivars AN1062, R2075, R719 and R1946 and susceptible cultivars GLP2 and GLP585 clustered together as expected. The others segregated randomly alongside the farmers’ germplasm. Resistant varieties AND1062, R2075, R719, R1946 and SCAM80 were more genetically related to marketable class of beans. R1946 R719, R2075 and AND1062 are closely related genetically compared to Mw001, KK15, Alulu and GLP2.

Conclusion: AFLP is a relatively informative technique that has a great potential of delineating susceptible and resistant Pythium root rot dry bean varieties, and can be used as a preliminary guide to carry out further analysis. It is notable that the AFLP markers used were not able to clearly distinguish all the cultivars comprehensively and should not be used alone in determining resistance levels. The information generated in this study will contribute to the propagation of acceptable market class bean lines with resistance to Pythium root rot for improved livelihood and increased food security.

Open Access Original Research Article

Leaf Epidermal Anatomy in Five Varieties of Capsicum annuum L. Solanaceae

D. A. Zhigila, F. B. J. Sawa, T. A. Aluko, F. A. Oladele, A. A. Abdul Rahaman

Journal of Experimental Agriculture International, Page 392-399
DOI: 10.9734/AJEA/2015/12825

Leaf epidermal micro morphological features were studied in five verities of Capsicum annum L. both quantitatively and qualitatively to evaluate the reliability of these characters for taxonomic consideration. These varieties are difficult to be recognized by using their dry samples. Varieties studied include var. abbreviatum, var. annuum, var. accuminatum, var. grossum and var. glabriusculum. Two types of stomata (anisocytic and tetracytic) were identified in all five varieties and the leaves were amphistomatic. There was high frequency of anisocytic stomata (66.67 – 95.24%) on both surfaces compared to tetracytic stomata (4.76 – 33.33%). Trichomes were absent on both leaf surfaces of variety grossum and var. abbreviatum; it was present on both surfaces of variety accuminatum while it was epitrichomatic and hypotrichomatic on varieties glabriusculum and annuum respectively. The shapes of the epidermal cells of the upper and lower surfaces were irregular and undulate in all five varieties. These features were found to be of good and reliable taxonomic use for delimiting the five varieties of C. annuum.