Open Access Original Research Article

Genotype-by-Environment Interaction and Stability Analysis in Grain Yield of Improved Tef (Eragrostis tef) Varieties Evaluated in Ethiopia

Habte Jifar, Kebebew Assefa, Kassahun Tesfaye, Kifle Dagne, Zerihun Tadele

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/jeai/2019/v35i530214

Aims: To assess the magnitude of genotype by environment interaction; possible existence of different mega-environments; and discriminating ability and representativeness of the testing environments.

Study Design: Randomized complete Block Design with three replications.

Place and Duration of Study: The study was conducted at Debre Zeit, Holetta and Alem Tena for two years (2015 and 2016) and at Adet, Axum and Bako for one year (2015).

Methodology: Thirty-five improved tef varieties were evaluated at nine environments. The G × E interaction were quantified using additive main effects and multiplicative interaction (AMMI) and the genotype and genotype by environment (GGE) biplot models.

Results: Combined analysis of variance revealed highly significant (P = 0.01) variations due to genotype, environment and genotype by environment interaction effects. AMMI analysis revealed 4.3%, 79.7% and 16% variation in grain yield due to genotypes, environments and G x E effects, respectively. G6 gave the highest mean grain yield (3.33 t/ha) over environments whereas G29 gave the lowest mean yield (2.49 t/ha). The GGE biplot grouped the nine testing environments and the 35 genotypes into four mega environments and seven genotypic groups. The four mega environments include: G-I (E1, E4 and E6); G-II (E2, E3, E7 and E8); G-III (E9), and G-IV (E5). E5, E6, E7 and E8 which had the longest vector were the most discriminating of all environments while, E1 and E4 which had the smallest angle with the average environmental axis were the most representative of all environments. Regarding genotypes, G6, G25, G34 and G16 were identified as the best yielding and relatively stable genotypes to increase tef productivity.

Conclusion: AMMI and GGE were found to be efficient in grouping the tef growing environments and genotypes.

Open Access Original Research Article

Growth, Nodulation and Nutrients Uptakes of Cowpea (Vigna unguiculata L. Walp) following Zinc Fertilizer Applications in the Semi-deciduous Forest Zone of Ghana

Z. P. Chakirwa, J. Sarkodie-Addo, T. Adjei-Gyapong, A. K. Lubobo, B. J. Bashagaluke

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/jeai/2019/v35i530215

Cowpea can fix atmospheric nitrogen through symbiotic association with indigenous rhizobia but unfortunately, the amount of N2-fixed is usually not enough due to the presence of ineffective or low numbers of indigenous rhizobia in the soil. The effect of Zinc applications on growth, nodulation and nutrient uptakes of cowpea was investigated during the major and minor cropping seasons (2016). Cowpea seed varieties were treated to foliar spray with three different rates of Zinc sulfate (0, 5 and 10 kg Zn ha-1) at 3 and 5 weeks after sowing. The split plot design was used for both cropping seasons. This study shows that the supply of Zn fertilizer applications did not affect growth and nodulation in 2016 major and minor cropping seasons. The application of the 5 kg Zn ha-1 led to better cowpea production and greatly improve the quantity (haulm and grain yield) and quality (NPK content and crude protein) of cowpea in both haulm and grain. The Zinc fertilizer significantly enhanced N2-Fixed in both cropping season’s trial investigating. These findings suggest that cowpea responds differently to Zinc Sulphate application depending on its rates and the application of the 5 kg Zn ha-1 is the optimum rate that will enhance the yield and nutrient quality of cowpea in the Semi-Deciduous Forest Zone of Ghana.

Open Access Original Research Article

Dry Matter Yield and Nutritional Characteristics of Elephant-Grass Genotypes

Rafael Souza Freitas, Rogério Figueiredo Daher, Ana Kesia Faria Vidal, Wanessa Francesconi Stida, Bruna Rafaela da Silva Menezes, Antonio Vander Pereira, Silvino Amorim Neto, Paulo Ricardo dos Santos, Verônica Brito da Silva, Romildo Domingos Gottardo

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/jeai/2019/v35i530216

In the elephant-grass germplasm, there are genotypes that show a large genetic variability differentiated by morphological, reproductive, agronomic and biochemical characteristics. As such, there is a selection of new and more adapted elephant-grass genotypes, with greater productivity and nutritional quality, which can cause an increase in the forage offer, especially during the dry season. Thus, this work aimed at evaluating, throughout two years, the productive performance and nutritional value of 53 elephant-grass genotypes to produce forage in the edaphoclimatic conditions in Campos dos Goytacazes city, Rio de Janeiro State, Brazil. The experiment was composed of 53 elephant-grass accessions from the Banco de Germoplasma da Embrapa Gado de Leite (Germplasm Bank of Embrapa Gado de Leite), located in Coronel Pacheco city, Minas Gerais state, Brazil. It was applied the randomized complete block experimental design with 53 accessions two replications. Cuttings were performed every two months, throughout two years, totaling ten cuttings. The morpho-agronomic and bromatological characteristics were assessed, and the statistical analyses were carried out applying the Computational Applicative in Genetic and Statistics, Genes. Results indicated that there is a wide genetic variability among the elephant-grass genotypes concerning the characteristics under study. The Mineiro, Guaçu IZ-2 and Acesso 91 – EMBRAPA genotypes were those that showed to be superior to all traits evaluated simultaneously. They proved to be the most productive and with higher nutritional quality. Therefore, they are the most indicated to produce forage in the edaphoclimatic conditions of Campos dos Goytacazes city, Rio de Janeiro State.

Open Access Original Research Article

Induction of Senescence and Foliar Abscission in Apple Trees with the Use of Abscisic Acid

Caroline de Fátima Esperança, José Luiz Petri, Andrea de Rossi, Marcelo Couto, André Amarildo Sezerino, Gentil Carneiro Gabardo

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/jeai/2019/v35i530217

Aims: Evaluate the effects of different concentrations of abscisic acid (ABA) on adult plants of productive age of ‘Daiane’ and ‘Fuji Suprema’, to follow the ecophysiological effects and their efficiency in inducing leaf senescence, sprouting and productivity, in the Midwestern region of the state of Santa Catarina.

Study Design: The experiment was arranged in a randomized block design with six replications. Place and Duration of Study: The experiment was carried out in the municipality of Caçador, Brazil (latitude 26º50’07” S, longitude 50º58’32” W, altitude 969 meters), during the growing seasons of 2013/2014 and 2014/2015.

Methodology: The apple fruit tree were submitted to the following treatments: 1) Control (without treatment), 2) abscisic acid 750 mg L-1, 3) abscisic acid 750 + 750 mg L-1, 4) abscisic acid 1500 mg L-1 and 5) abscisic acid 1500 + 1500 mg L-1. ABA applications in the first year were carried out on May 2, 2013 in treatments 2, 3, 4, and 5, and after 11 days (05/13/13) the plants of treatments 3 and 5 were sprayed again. In the second year, ABA applications were carried out on May 6 and 15, 2014, following the same application methodology described for the first year. As the source of abscisic acid (ABA) the commercial product ProTone® (20% i.a.) was used, without the use of adjuvant. The exogenous application of ABA was effective in promoting the senescence and leaf fall of the ‘Daiane’ and ‘Fuji Suprema’ cultivars. In the 2013/2014 season, the concentration of 750 mg L-1 was enough to induce 100% leaf fall in 'Daiane' plants. However, a difference was observed between the concentrations of ABA used. There was a difference between concentrations and number of applications. Lower concentrations were efficient and deflated as much as the higher concentration. The application of ABA induces the abscission of apple leaves in early autumn in 'Daiane' and 'Fuji Suprema' apple plants. The ABA does not affect shoots of axillary buds and anticipates the beginning of shoots.

Open Access Original Research Article

Technological Analyze of Cassava Production in the City of Campos Dos Goytacazes – RJ

Tales Neri Borsoi, Silvio de Jesus Freitas, Paulo Marcelo de Souza, Patrick Martins Barbosa Brito, Waldinei Souza da Silva, Laura Pereira Salomão Soares, Samara do Rosário Medeiros, Larissa Carvalho da Silva

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/jeai/2019/v35i530218

This study analyzes the technological conditioning factors of cassava production in the municipality of Campos dos Goytacazes-RJ, seeking to elucidate the limitations and technological barriers that have contributed to the decline of crop production and productivity. A descriptive and quantitative methodology was adopted, in which the Survey method was used to analyze the technological factors through a questionnaire applied to 157 cassava producers in the field. The results evidenced the low degree of modernization of cassava in the municipality of Campos-RJ, intensive and extractive land use, generally produced on a small scale and with a low level of capitalization and productivity of work and land. This context seems to stimulate a vicious cycle, of low performance of the crops and profitability, low capacity of accumulation of resources, and capital and technological possibilities, favoring a gradual process of discouragement of the production. Without the possibility of gains and accumulation of income, the degree of uncertainty and risk tend to increase, as adversities and external forces make the permanence and perpetuation of the activity even more difficult, to emphasize the climatic factors and obstacles of commercialization and market. Thus, the research reinforces the need to evaluate technological alternatives that fit the local culture, as well as mechanisms that make them accessible to producers, such as: technical assistance, rural credit, social organization, among other public policies which aim to reduce the aggravation of rural activity in the municipality.