Open Access Original Research Article

Analysis of Seed Vigor Responses in Soybean to Invasive Silver Carp (Hypophthalmichthys molitrix) Protein Hydrolysate Treatments

S. P. Thomson, A. M. Liceaga, B. M. Applegate, R. D. Martyn

Journal of Experimental Agriculture International, Page 178-191
DOI: 10.9734/AJEA/2015/13087

Aim: To produce fish protein hydrolysates (FPH) from invasive silver carp (Hypophthalmichthys molitrix) under controlled hydrolysis conditions, and to examine the effects of FPH on seed vigor, using standard vigor tests.

Methodology: Soybeans were treated with FPH hydrolyzed for 1, 5.5 and 10 hrs with papain (FPH-Pa), pepsin (FPH-P) and trypsin (FPH-T), respectively. Overall vigor tests (accelerated aging and warm and cold germination dry weight, height, total phenolics and guaiacol peroxidase assessment-GuPx) were compared to a distilled-water control over a 12-day germination period.

Results: Seeds treated with FPH-P and FPH-Pa at 1 hr (23% degree of hydrolysis) elicited the greatest growth responses. FPH-Pa at 1 hr increased (P=0.05) weight (1.38 g) and height (53 mm) compared to water control (1.25 g and 46.8 mm, respectively). FPH-Pa at 1 hr also had the highest GuPx values, which are indicative of lignification. FPH-Pa appeared to stimulate lignification and thus enhance weight and height of the seedling. FPH-P elicited the greatest phenolic response, with the highest total phenolic content on day 4 (1.27 mg GAE/g FW) and day 12 (1.43 mg GAE/g FW) compared to water control (0.59 mg GAE/g FW on day 4, 1.10 mg GAE/ g FW on day 8). Higher phenolic content may have protected against oxidation during accelerated aging vigor test, resulting in higher germination rates (53.8% germination) for soybeans primed with FPH-P at 1 h compared to water controls (32.2% germination). Most FPH treatments increased germination under warm conditions, compared to water control. GuPx values overall were higher in FPH-treated soybeans.

Conclusion: Results suggest that the use of FPH produced with the enzymes papain and pepsin at 1 hour of hydrolysis are comprised of free amino acids and peptides that are beneficial to the stimulation of the proline-linked pentose phosphate pathway, which enhanced the vigor parameters measured.

Open Access Original Research Article

Effect Crude Protein Levels on the Broodstock Spermatic Quality of Nile tilapia (Oreochromis niloticus)

Marinez Moraes de Oliveira, Mônica Rodrigues Ferreira, Marcilia Barbosa Goulart, Viviane de Oliveira Felizardo, Luis David Solis Murgas, Estefânia de Souza Andrade, Ivan Bezerra Allaman, Galileu Crovatto Veras, Diego Vicente da Costa, Priscila Vieira Rosa

Journal of Experimental Agriculture International, Page 192-199
DOI: 10.9734/AJEA/2015/13044

Objective: The purpose of this work was to evaluate the reproductive performance and the toxicity of DMSO cryoprotectants and methanol toward semen of Nile tilapia (Oreochromis niloticus), fed using diets containing different Crude Protein (CP) levels.

Study Design:  completely randomized design.

Place and Duration: The experiment was performed for 90 days, at the Hydrobiology and Fish Culture Station of Eletrobrás Furnas, in São José da Barra, State of Minas Gerais, Brazil.

Methodology: 15 broodstock males with around 30 months old were used. They were stocked in ten reservoirs of storage capacity around 8 cubic meters, in which treatments consisted of five diets containing different levels of crude protein (32, 34, 36, 38 and 40%) and 9.5kcal/kg of digestible energy per gram of protein. For the in-natura semen, the statistical analyses were carried out using data obtained from a completely randomized design, while for diluted semen, the completely randomized design was also used but, in 5×2 factorial scheme, representing 5 levels of protein and 2 cryoprotectants.

Results: The hepatosomatic index (HSI), gonadosomatic index (GSI), rate and duration of Nile tilapia males in-natura semen motility were not influenced (p>0.05) by the crude protein levels in the diets. After dilution, significant differences were observed for motility (p=0.053) and motility duration (p=0.021). The effects of third and fourth degree occurred for the rate (p=0.0349) and duration (p=0.0220). As these adjustments do not allow a biological interpretation, the Tukey multiple comparison test was used. The diet containing 36% of crude protein level showed mean motility rate similar (p>0.05) to those of treatments containing 32, 34 and 40% of crude protein and mean motility rate inferior (p<0.05) to treatment containing 38% of crude protein. For motility duration, fish fed using diet containing 38% and 40% of crude protein showed significant differences (p<0.05) to only the group of fish fed using diet containing 34% of crude protein.

Conclusion: Diet containing 32, 38 and 40% of crude protein level does not deteriorate the semen quality, so that may be used for feeding tilapia broodstocks. As protein is an expensive input, we can infer that 32% of crude protein is sufficient to determine good quality gametes.

Open Access Original Research Article

The Influence of Sowing Dates on the Growth and Yield of Two Maize (Zea mays L.) Varieties Cultivated under Southern Guinea Savannah Agro-Ecological Zone

Terkula Joseph Maga, Terkimbi Vange, James Onuh Ogwuche

Journal of Experimental Agriculture International, Page 200-208
DOI: 10.9734/AJEA/2015/12661

Maize requires optimum growth conditions to express its genetic potential. Evaluating maize under different sowing dates provides a novel strategy of improving its productivity. To achieve this, a field study was conducted at the Teaching and Research Farm of the University of Agriculture, Makurdi during 2012 cropping season to determine the effect of different sowing dates on the growth and yield of maize. Makurdi is located under the Southern Guinea Savannah Agro-ecological Zone. Two maize varieties, TZESR-Y and QPM were obtained from the Department of Plant Breeding and Seed Science, University of Agriculture, Makurdi and evaluated under three different sowing dates (4th May, 18th May and 1st June, 2012). The factors were arranged in a 2x3 factorial style laid in a randomised complete block design with three replications. Data were collected on morphological parameters and subjected to analysis of variance. The result showed that sowing date had significant effect on number of leaves/plant, ear girth and grain yield. Early sowing had significant and positive effect on grain yield. The interaction effect of variety and sowing date was significant for plant height, number of leaves/plant and grain yield. Delayed sowing to 18 May and 1 June resulted in significant reduction of grain yield from 130.67 kg/plot to 127.18 kg/plot in QPM and 126.67 to 125 kg/plot in TZESR-Y. QPM when sown on 4 May gave the highest grain yield compared to when sowing was delayed to May 18 and June 1. This result implies that May 4 sowing date appears to provide the optimum conditions for maize cultivation under Southern Guinea Savannah agro-ecological Zone.

Open Access Original Research Article

Activity of Catambra Extracts against Meloidogyne spp.

Nikoletta G. Ntalli, Eleni Nasiou, Chrysostomos Oplos, Federico Ferrari, Urania Menkissoglu-Spiroudi

Journal of Experimental Agriculture International, Page 209-216
DOI: 10.9734/AJEA/2015/12211

Aims: In this study we tested four Catambra commercial formulates (hydroalcoholic extracts) used as insecticides in Italy, against Meloidogyne incognita and Meloidogyne javanica.

Catambra plant (Ambrogios, Catalpa) a European patent belonging to Ambrogio srl, rich in an iridoid glycoside catalpol, is used to date as a mosquito deterrent, but no data exist on its biological activity against soil parasites as Meloidogyne sp. Catalpa species demonstrate various biological properties of pharmaceutical and agronomical interest, mainly due to their contents in glycosides.

Place and Duration of Study: All paralysis bioassays were performed in Pesticide Science Laboratory, of Aristotle University Thessaloniki, Greece, while chemical analysis in Department of Life and Environmental Sciences, University of Cagliari.

Materials and Methods: The activity was tested in paralysis bioassays with freshly hatched second-stage juveniles (J2) immersed in test solutions for four time periods (12, 24, 48 and 96 hours). Catalpol contents of the extracts were measured by means of HPLC/MS and its activity was also tested against J2. The effect of exhaustive evaporation of hydroalcoholic extracts prior use in bioassays was also studied for nematicidal activity.

Results: Out of the four extracts tested without being evaporated first, two extracts (C-2 and C-4) exhibited activity and the EC50/48h on M. incognita were calculated at 640 and 728 μg/ml. On the other hand, M. javanica was proven sensitive only to the C-4 extract and the activity had an EC50/48h value at 500 μg/ml. When extracts were exhaustively evaporated before use, only the C-4 paralysed J2 and the EC50/48h values were 728 and 500 μg/ml against M. incognita and M. javanica, respectively. Interestingly, catalpol was not found to be nematicidal at the concentration range of 100 to 1000 μg/ml. The nematicidal activity of the extracts was therefore not correlated with their content in catalpol. This was confirmed by the chemical composition study, since the C-4 extract, exhibiting activity against both species, was of low contents in catalpol (21 μg/ml), and the C-3 extract that had the highest contents in catalpol (358 μg/ml) did not paralyse J2.

Conclusion: Catambra nematicidal activity is not based in its contents in catalpol, and further studies are conducted to delineate for activity among other constituent components.

Open Access Original Research Article

Genetic Diversity Studies in 29 Accessions of Okra (Abelmoschus spp L.) Using 13 Quantitative Traits

HM Amoatey, GYP Klu, EK Quartey, FL Sossah, MM Segbefia, JK Ahiakpa

Journal of Experimental Agriculture International, Page 217-225
DOI: 10.9734/AJEA/2015/12306

Aims: Twenty nine (29) local and exotic lines (accessions), of okra (Abelmoschus spp L.) were evaluated for variation in phenotypic traits.

Study Design: They were laid out in a Randomised Complete Block Design (RCBD) with four replications and evaluated based on 13 quantitative characters.

Place and Duration of Study: Research farm of the Biotechnology and Nuclear Agriculture Research Institute (BNARI), Ghana Atomic Energy Commission (GAEC), Department of Nuclear Agriculture and Radiation Processing, Graduate School of Nuclear and Allied Sciences, University of Ghana, between June 2011 and July 2012.

Methodology: The accessions were grown in the field, each on a subplot measuring 3.5 m x 2.5 m, with seeds sown at a spacing of 0.70 m x 0.50 m. Data were collected using the International Plant Genetic Resources Institute (IPGRI) Descriptor List for okra.

Results: The accessions exhibited significant variation in all quantitative traits studied. Block coefficients of variation were extremely low, implying that results obtained are reliable and repeatable over replications. Cluster analysis based on Canberra, Furthest Neighbour Similarity Matrix grouped the accessions into two major clusters and subsequently into four sub-clusters, with no duplications, based on the characters studied. Seven pairs of quantitative traits were positive and significantly correlated (P ≤ 0.05) while three were highly significantly associated (P ≤ 0.01). The highest correlation (r = 0.95) was between number of days to 50% flowering (NDFl) and number of days to 50% fruiting (NDFr).

Conclusion: The pattern of clustering showed some degree of association between quantitative characters and geographic origin of the collections. Five Principal Components (PCs) accounted for 78.51% of the total variance, with PC1 recording 32.44%. Different traits contributed differently to total genetic variance.

Open Access Original Research Article

Effects of Sodium Azide (NaN3) on Seeds Germination, Plantlets Growth and In vitro Antimalarial Activities of Phyllanthus odontadenius Müll. Arg.

Rufin Kikakedimau Nakweti, Claudine Franche, Sébastien Luyindula Ndiku

Journal of Experimental Agriculture International, Page 226-238
DOI: 10.9734/AJEA/2015/11076

Aims: “This study aims to investigate the production of secondary metabolites of P. odontadenius against malaria using some concentrations of sodium azide (NaN3) and to choose those with high in vitro antimalarial activities.”

Study Design: Laboratory experiment tests; Identification of plant material, Immersion of seeds in SA concentrations, In vitro culture of seeds, In situ culturing plantlets, Extraction of Phyllanthus odontadenius aerial parts, Phytochemical screening, in vitro antiplasmodial tests to determine the inhibition of concentration killing 50% of parasite population (IC50).

Place and Duration of Study: Department of Biotechnology and Molecular Biology, Department of Biochemistry: General Atomic Energy Commission, Regional Center of Nuclear Studies, P.O. Box. 868 Kinshasa XI, Democratic Republic of the Congo (DRC). National Institute of Biomedical Research (NIBR) at Kinshasa/Gombe (DRC). The experiments were conducted firstly during August and December 2011 and secondarily during May and September 2012.

Methodology: Seeds of P. odontadenius were obtained after oven drying at 45°C and they were immersed in SA at concentrations ranging firstly between 0 to 10 mM; secondarily between 0 to 20 mM. Seeds were germinated on Murashige and Skoog medium (MS) and plantlets were transferred in situ. In addition some parameters such as height, collar diameter, number of branches and biomass from first generation were analyzed. Phytochemical screening was released. The in vitro antiplasmodial activities assays on clinical isolates of P. falciparum was determined.

Results: Results showed that SA had positive effects on growth parameters of P. odontadenius in the M1 generations with greater effects observed with treatment exceeding 10 mM. For the in vitro antimalarial activities from to extracts obtained with aerial material parts from directly immersed seeds (M1), the effects observed with plant extracts from seeds dipped in SA were higher than those from untreated seeds. IC50 values were ranged between 1.04±0.02 μg/ml (10 mM) to 12.77±5.83 μg / ml (0 mM) for the first assay. And for the second test, the in vitro antiplasmodial activities varied between 1.47±1.07 μg/ml (10 mM) to 21.60±7.13 μg/ml (2.5 mM). The best activities were observed with SA solutions exclusive of 5 mM to 10 mM. The SA lethal doses were 4.76 mM for LD30 and 10.99 mM for LD50.

Conclusion: Treatment of P. odontadenius seeds with SA induced stimulation of parameters which increase linearly with increasing concentrations of SA. Some secondary metabolites were synthesized for example alkaloids compounds compared to the untreated seeds of                         P. odontadenius with a more important synthesis in phenolic compounds. The in vitro antiplasmodial activities on the clinical isolates P. falciparum showed low antimalarial activities from M1 controls (0 mM) than that of extracts from treated plants. The high inhibitory effects (1,04±0.02  µg/mL or 1.47±1.07 µg/mL for 10 mM) of crude extracts plants from treated seeds have justified the usefulness of SA in plant breeding particularly in the increasing production of secondary metabolite against malaria in the World.

Open Access Original Research Article

Colloidal Stability and Potential Structural Deformation Index of Four Nigerian Soils

I. A. Nweke, P. C. Nnabude

Journal of Experimental Agriculture International, Page 239-251
DOI: 10.9734/AJEA/2015/11171

This study was undertaken to evaluate the effect of continuous cultivation on the colloidal stability and potential structural deformation index (PSDI) of four Nigerian soils. The four soils used for the study were; Entisol from Nsukka Hill, Ultisol from Nsukka poultry site, Inceptisol from Eha-Amufu and Inceptisol from Ikem, in Nsukka area of south eastern, Nigeria. The land use types considered were fallow and cultivated. The soils collected from 0-25cm depth were separated into five aggregate fractions, 5-2 mm, 2-1 mm, 1-0.5 mm, 0.5-0.25 mm and 0.25 mm, and changes in their colloidal stability and PSDI properties due to cultivation were determined for both dry and wet sieved fractions. The result of the study showed that the aggregates in the cultivated soils were less stable than those in the fallow soils. The colloidal stability result show less structural stability of the aggregates by the high DR values obtained. The correlation result between silt+clay and dispersion ratio (DR) for all the land use types showed that the contribution of silt+clay to the stability of these soils was low. No significant correlation was observed between Organic Carbon (OC) concentration and PSDI values and between silt + clay and total N, available P and OC in all the soils. The potential of the aggregates to disintegrate upon contact with water was more in Inceptisiol at Eha-Amufu cultivated,  IEh (C) 84.4% > Ultisol at Nsukka cultivated, UNsk (C) 74.4% > Ultisol at Nsukka fallow, UNsk (F) 72.0% > Inceptisol at Eha-Amufu fallow, IEh (F) 68.3% > Inceptisol at Ikem cultivated, Iik (C) 65.5% > Entisol at Nsukka fallow, ENsk (F) 65.2% > Inceptisol at Ikem fallow, Iik (F) 64.7% > Entisol at Nsukka cultivated ENsk (C) 61.8%. From the results of this study it is evident that the colloidal stability and PSDI of dry aggregates and wet-aggregates differ substantially even though their diameters are the same. Hence they will have differing impact on the soils.

Open Access Original Research Article

The Effects of Temperature on Storage Life of Mango (Mangifera indica L.)

V. E. Emongor

Journal of Experimental Agriculture International, Page 252-261
DOI: 10.9734/AJEA/2015/12174

A laboratory experiment was undertaken to investigate the effects of storage temperature on storage life and quality of mangoes. The mango fruit cultivars Tommy Atkins, Haden, Kent and Keitt were used for the study in a completely randomized experimental design. The storage temperatures were 5, 8, 10 and 12ºC. The results of the study showed that storage temperature and mango cultivars significantly (P ≤ 0.01) affected the incidence and severity of chilling injury in mango. Chilling injury developed in all the mango cultivars under study stored at temperatures of ≤ 12ºC, though the severity significantly (P ≤ 0.01) varied with cultivar. The mango cultivars stored well for 7 weeks at 12ºC without the development of physiological disorders and after storage, the fruit underwent normal ripening process with colour (carotenoids and anthocyanins) development, high total soluble solids and low titratable acidity. It was concluded that in order to extend the shelf-life and marketing period of mango, the fruit should be stored at 12ºC and 90-95%RH, because the fruit will not suffer from chilling injury and will undergo normal ripening process. For the mango cultivar Kent, it could initially be stored at 10ºC for 3 weeks and then transferred to 12ºC, this will extend the shelf life of the fruit for more than 7 weeks, hence extending the marketing period and availability of the fruit beyond the harvesting period.

Open Access Original Research Article

Phytotoxic Potentials of Cold and Hot Aqueous Extracts of Chromolaena odorata against Fungal Deteriorating Agents of Yam Tubers (Dioscorea rotundata, Poir) after Harvest

J. Y. Ijato, P. O. Tedela

Journal of Experimental Agriculture International, Page 262-266
DOI: 10.9734/AJEA/2015/12139

The antifungal activities of cold and hot aqueous extract of C. odarata against four isolated fungi namely Aspergillus flavus, Aspergillus glaucus, Aspergillus niger and Botryodiplodia theobromae causing post-harvest rot disease of yam tubers were investigated. All the concentrations; 10g/100ml to 50g/100ml of both hot and cold extract of C. odorata inhibited significantly the radial mycelial growth of all the test fungal organisms with percentage inhibition ranging from 77.78% to 98.89%. However, 10/100ml of cold extract and 30g/100ml of hot extract inhibited B. theobromae to 90.48% and 97.14% respectively; 20g/100ml of cold water extract and 30g/100ml of hot extract inhibited B. theobromae to 90.48% and 97.14% respectively; 20g/100ml of cold extract and 30g/100ml of hot extract inhibited A. flavus to 95.56% and 98.22% respectively; 30g/100ml of cold and hot extract inhibited A. glaucus to 97.77% and 98.89% respectively and 70g/100ml of cold extract and 10g/100ml of hot extract inhibited A. niger to 91.92% and 98.08% respectively. Both hot and cold extract of C. odorata were found to be very potent against all the isolated yam tuber rot pathogens. The test plant therefore could serve as preferred alternatives to synthetic chemicals because it is readily available and produced no known negative effect on the environment.

Open Access Original Research Article

Economic Efficiency Analysis of Pineapple Production in Edo State, Nigeria: A Stochastic Frontier Production Approach

L. O. Akhilomen, G. M. Bivan, S. A. Rahman, S. A. Sanni

Journal of Experimental Agriculture International, Page 267-280
DOI: 10.9734/AJEA/2015/13488

This study analyses farmers’ overall efficiency in pineapple production in Edo State, Nigeria. Data were collected through well structured questionnaire administered on 175 pineapple farmers selected using a multi-stage sampling technique and analyzed using descriptive statistics and the stochastic frontier production and cost function models. Result revealed that while farm size and labour significantly influenced production efficiency, the cost of farm, suckers and output were significant in influencing cost efficiency. Average technical, allocative and economic efficiencies of the farmers were 0.70, 0.68 and 0.64 respectively indicating ample opportunity for farmers to increase their productivity. The return to scale (RTS) for the production function revealed that the farmers operated in the rational zone (stage II) of the production surface having an RTS of 0.52. The analysis further indicated that the presence of technical and allocative inefficiencies had effect on pineapple production as depicted by the significant estimated gamma coefficient of each model and the predicted technical and allocative efficiencies within the farmers. The study recommends the need to increase output through more intensive use of land, availability of high yielding pineapple varieties and the effective and efficient utilization of labour and fertilizer inputs. It also recommends that farmers be encouraged to join cooperatives and extension services should intensify their efforts in training and mobilizing farmers for improved pineapple production. An easier access to credit from formal sources, notably micro-credit institutions and farmers’ education are essential to improve productivity and profitability of pineapple production in Nigeria. Policies that focus on ways of attracting and encouraging the youths who are agile and stronger to embark on pineapple production should be pursued such as the setting up of fruit processing factories or industries in the rural areas.