Open Access Original Research Article

Evaluation of the Insect Pest Population Dynamics in Common Bean Cultivars in Relation to the Foliar Fertilisation with Potassium Silicate

André Luiz Alves, Antonio Carlos Torres da Costa, Marcos Cesar Mottin, Vanda Pietrowiski, José Barbosa Duarte Júnior, Meirieli Nunes

Journal of Experimental Agriculture International, Page 1-12
DOI: 10.9734/JEAI/2018/44031`

Effect of foliar fertilisation with potassium silicate on the abundance of pest insects belonging to hemiptera, diptera, coleoptera and lepidoptera in two different genotypes of common bean, cultivated in two sowing seasons. The experiment was conducted under field conditions during the Rainy Season from August to December 2014 and the Dry Season from February to June 2015 in a rural area of Assis Chateaubriand, State of Paraná, Brazil. The experimental design was a completely randomised 2 x 5 factorial design with four replications. The first factor refers to the bean genotypes (IPR Campos Gerais and IPR Tuiuiú), and the second factor refers to the doses of potassium silicate (0.0, 250, 500, 750 and 1000 ml ha-1). Potassium silicate at specified doses were sprayed bi-weekly during phenological stages V3 to R8. Insect pest samplings were carried out weekly during the phenological stages Vthrough R8 for both the experiments. Foliar fertilisation with potassium silicate decreased pest insects on the common bean genotypes was studied. IPR Tuiuiú genotype presented a smaller quantity of hemiptera insects in compared to IPR Campos Gerais during the reproductive stage of the Rainy Season Crop (2014). During the vegetative stage of the Dry Season Crop (2015), IPR Campos Gerais presented a smaller quantity of diptera insects in compared to IPR Tuiuiú. Interactions between treatments and the genotypes evaluated occurred, decreasing que population of hemiptera and lepidoptera insects during the vegetative and reproductive stages of the Dry Season Crops (2015). IPR Campos Gerais Genotype represented a smaller quantity of lepidoptera and hemiptera insects than IPR Tuiuiú.

Open Access Original Research Article

Multivariate Analysis of Genetic Diversity in the Ethiopian Garden Cress (Lepidium sativum L.) Genotypes

Legesse Tadesse, Firew Mekbib, Adugna Wakjira, Zerihun Tadele

Journal of Experimental Agriculture International, Page 1-16
DOI: 10.9734/JEAI/2018/43983

Aims: The use of multivariate techniques is an important strategy for germplasm classification and study of genetic relationships among genotypes. This study was designed to evaluate using multivariate analysis the genetic divergence among 112 garden cress (Lepidium sativum L.) genotypes collected from different Administrative Zones of Ethiopia.

Methodology: The experiment was conducted at Haramaya University Research Site and Kulumsa farmer field. Twelve agro-morphological traits were evaluated in Randomized Complete Block Design (RCBD) with two replications. Region-wise analyses of variance, principal component and cluster analyses were applied.

Results: The analysis of diversity pattern based on the region of genotype origin revealed highly significant variability within and between regions of origin for almost all studied traits. The geographical pattern of distributions of genotypes in groups were not dependent on the regions of origin. The first three principal components explained 80.3% of the total variations suggesting that traits such as number of secondary branches, days to maturity, plant height, biomass/plant and biomass/plot, harvest index, grain yield/plant, thousand seed weight and grain yield/ha are the principal discriminatory traits in the germplasm studied. The cluster analysis categorised the 112 genotypes into six groups. The most diverse genotypes were found between cluster I and II which could be used for producing new genetic variability and exploitation of heterotic effects with the traits of interest in crossing programs.

Conclusion: The genetic diversity existing in the current study could be utilised in the genetic improvement of the Ethiopian garden cress germplasm.

Open Access Original Research Article

Dynamics of Natural Regeneration in a Fragment of Dense Ombrophilous Forest in Urban Area

Adão Batista de Araújo, Djailson Silva da Costa Júnior, Yana Souza Lopes, Paullyne Charllotte Gonçalves Celestino, Anália Carmem Silva de Almeida, Lúcia de Fatima de Carvalho Chaves

Journal of Experimental Agriculture International, Page 1-15
DOI: 10.9734/JEAI/2018/44621

The objective of this study was to evaluate the dynamics of natural regeneration in an urban forest fragment in Recife - PE. Ten plots of 5 m x 5 m were installed, the individuals with height (H) ≥ 1 m and the circumference at breast height (CBH) ≤ 15 cm were measured in 2010 and 2017. The floristic composition, diversity, phytosociological parameters and natural regeneration by height and total classes were evaluated. The individuals were distributed in height classes, where: C1 = H ≥ 1.0 up to 2.0 m; C2 = H> 2.1 to 3.0 m; C3 = H> 3.0 m and CAP <15 cm. The families with the highest number of individuals in both years were: Moraceae, Burseraceae, Euphorbiaceae and Fabaceae. Together, these families accounted for 74.57% of the total number of individuals in 2010 and 73.40% in 2017. The predominance of individuals in the first class was observed, followed by the second and third. The species with the highest Total Natural Regeneration (TNR) were: Artocarpus heterophyllusHelicostylis tomentosaProtium giganteumProtium heptaphyllumBrosimum guianense and Mabea occidentalis, which together corresponded to a TNR of 60.09% in 2010 and 59.03 % in 2017. The species with the highest number of recruitments were Brosimum guianenseArtocarpus heterophyllusHelicostylis tomentosaSiparuna guianensis and Cymbopetalum brasiliense. It was concluded that there were no significant differences in the fragment within the time interval studied.

Open Access Original Research Article

Different Substrates in Seedling Production of Caesalpinia pyramidalis Tul

Natacha Nara Gonçalves de Mello da Conceição, Fabiane Pereira Machado Dias, Ésio de Castro Paes, Fagner Taiano dos Santos Silva, Rafaela Simão Abrahão Nóbrega, Júlio César Azevedo Nóbrega

Journal of Experimental Agriculture International, Page 1-7
DOI: 10.9734/JEAI/2018/44805

The use of native species for the recovery of degraded areas has been of great relevance, however, there is a deficiency in studies aimed at the Northeast region of Brazil, which presents one of the largest areas under desertification in the South American continent. The region has a diverse native flora of high cultural and economic relevance such as Caesalpinia pyramidalis Tul, popularly known as catingueira that stands out for the rusticity and use in diverse areas medicinal, logging, cultural, animal feeding, among others. The objective of this work was to evaluate the effects of chemical fertilisation on different substrate sources on the emergence and initial growth of Caesalpinia pyramidalis seedlings. For the constitution of the substrates samples, Yellow Oxisol distrocoeso were collected at 0.50 m depth and superfine vermiculite. Also organic manure and organic compound were used. The emergence and morphological features (area and total dry mass, height, diameter, chlorophyll A and B) were evaluated. The seedlings of Caesalpinia pyramidalis placed on substrates consisting of organic compound in the ratio 1:1:1 (compound: soil: vermiculite) and 2:1:1 (compound: soil: vermiculite) and cattle manure 2:1:1 (manure: soil: vermiculite) generated satisfactory results for the development of the crop. There was no interaction (p> 0.05) between the addition of NPK and the types of substrates evaluated for the studied variables.

Open Access Review Article

A Discourse Analysis of Postmodern Agricultural Research and Extension Models: An Epistemological Perspectivism

Getachew Sime

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/JEAI/2018/26180

A number of agricultural research and extension models are developed during postmodernism in order to increase the agricultural productivity and improve the livelihoods of farmers in developing countries. The objective of this review paper is to analyze the dynamism of these models following a postmodern epistemological perspectivism. One of the predominant agricultural research and extension models in postmodernism is the Transfer-of-Technology (ToT). It is a typical model for both national and international agricultural research and extension. In this model, all the key research decisions are made by scientists who experiment on research stations or under controlled and simplified conditions in farmers' fields. The resulting agricultural technology is then handed over to the extension services for transfer to passive farmers. This model is a typical positivist and reductionist research of normal science approach, with high input package and top-down extension. It succeeds in the uniform and controlled conditions of the resource rich farmers of the western, but fails to resolve the challenge of farmers in developing countries. Therefore, for many agricultural technologies innovated within the ToT top-down framework, failure rate in developing countries remains high. Meanwhile, this discontent has necessitated the realization of ‘participatory movements’ which consider farmers as key partners in research and extension. Thus, the attendance in the ‘participatory movements’ has become clearly discernible with increasing reputation. These ‘movements’ have progressed collectively as Participatory Research and Development (PRD) with greater sophistication and formalization of  theoretical foundations. The PRD model is a methodological and philosophical contextualization to local reality that disdains positivism and reductionism but salutes pluralism and holism. This re-contextualization makes a new claim of empowering farmers. As a result, there is an indication that the ToT model has gradually losing its pre-eminence to the PRD approach in developing countries. Yet, contemporary agricultural research and extension in developing countries are based on a mixture of the ToT and PRD models. Particularly, international agricultural research institutes still hold the strong line of positivism and reductionism. For improving the livelihood of farmers in developing countries, therefore, a consistent attention need to be given to a more participatory, empowering, holistic and pluralistic PRD model that strengthens the agricultural research institutes-researchers-extension systems-farmers linkage.