Open Access Original Research Article

Sensitivity of Different Chenopodium album L. Biotypes to Metamitron

Henning Nordmeyer

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/JEAI/2018/38368

Chenopodium album L. populations were tested for sensitivity to the herbicide metamitron. Sensitivity was assessed by a dose-response relationship and ED50 values. Seeds were collected from single plants in different districts of Germany and in different types of locations (non-agricultural land, fallow land, conventional farming and organic farming). Additional seeds were collected from single plants within a field in a 12-metre grid space. Results were evaluated for different districts and different types of locations and for a single field. There were only small variations in sensitivity at low application rates. Significant differences could be estimated between districts. All Chenopodium album L. populations were sensitive to metamitron. No resistant plants were found.

 

Open Access Original Research Article

Prevalence of Mosaic and Leaf Curl Diseases of Okra (Abelmoschus esculentus L. Moench) in the Central Region of Ghana

Elvis Asare-Bediako, Faustina Agyarko, Kingsley J. Taah, Aaron Tettey Asare, Justice Sarfo, Kwame Agyei Frimpong, Joseph Nyarko

Journal of Experimental Agriculture International, Page 1-16
DOI: 10.9734/JEAI/2018/37421

Aims: To determine the incidence and severity of okra mosaic (OMD) and okra leaf curl diseases (OLCD) in the Central region of Ghana and to assess farmers’ perception on the incidence and management of these viral diseases.

Study Design: Descriptive survey involving household and field surveys.

Place and Duration of Study: Komenda-Edina-Eguafo-Abirem (KEEA) municipality in the coastal savannah zone, Assin North district in the forest zone and Ajumako-Enyan-Essiam (AEE) district in the forest-coastal savannah transitional zone, between June 2009 and December 2015.

Methodology: Household data were collected using structured questionnaire from 180 respondents (60 farmers per district)using the multi-stage procedure, and analyzed using descriptive and inferential statistics. Disease incidence (DI) and severity scores (SS) of OMD and OLCD were determined in thirty-six (36) okra fields selected from each of the three districts. The field data were subjected to analysis of variance (ANOVA) and the means separated with least significant difference (LSD) method at 5% probability level.

Results: There was a high prevalence of OMD and OLCD in the districts surveyed. Incidence and severity scores of OLCD at the coastal savannah zone were not significantly different from the forest zone but were significantly higher (P=0.05) than the transition zone. The study also revealed that the majority of the farmers were males; had small farm holdings and practiced monocropping. The majority of the respondents had observed OMD and OLCD in their farms and had managed these viral diseases solely with pesticides. Pesticides have also been abused by the majority of the farmers who did fortnightly spraying, not observing appropriate pre-harvest intervals and also used insecticides not registered or recommended for vegetables.

Conclusion: Viral diseases are highly prevalent and severe in okra farms in the study area and this is partly due to poor agronomic practices by the farmers.

Open Access Original Research Article

Methodology for the Genetic Improvement of Coriander Aiming for Resistance to the Root Knot Nematode

Ana Maria Maciel dos Santos, Kleyton Danilo da Silva Costa, Jackson da Silva, Jacqueline Wanessa de Lima Pereira, Dimas Menezes, José Luiz Sandes de Carvalho Filho

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/JEAI/2018/39485

Coriander is among the most cultivated hardwoods in Brazil, but its production can be compromised due to damage caused by phytonematodes in the growing areas. Although there are several coriander cultivars in the market, none exhibit resistance to nematodes of the genus Meloidogyne. Thus, the present work aims at proposing a methodology to be used in coriander breeding programs for resistance to M. incognita. The experiment was carried out in a greenhouse at the Federal Rural University of Pernambuco. Five coriander cultivars, handled in three types of containers and three types of substrates, inoculated 15 days after sowing with 1,200 eggs per plant, were evaluated in a randomized block design with three replications in a subdivided plot arrangement. At 45 days after inoculation, the evaluation was started, quantifying the incidence of galls, number of galls in the root system, number of eggs and estimation of the nematode reproduction factor for each cultivar. The use of a 128-cell tray with Basaplant® substrate and experimental plot consisting of eight plants, a value obtained from estimation by the maximum modified curvature method, was the methodology that presented better results, being able to be used in the selection of coriander genotypes for resistance to M. incognita.

 

Open Access Original Research Article

Pulp Browning and Bioactive Compounds in Fruits from Peach Trees Grafted on Different Rootstocks

Caroline Farias Barreto, Marines Batalha Moreno Kirinus, Pricila Santo da Silva, Cesar Valmor Rombaldi, Marcelo Barbosa Malgarim, José Carlos Fachinello

Journal of Experimental Agriculture International, Page 1-7
DOI: 10.9734/JEAI/2018/39710

Aims: This study aimed at evaluating the quality of Chimarrita peaches from plants grafted on seven rootstocks on the day they were harvested and after 21 days of cold storage, followed by 3 days at room temperature.

Study Design: The experiment was conducted as a randomized complete design in factorial scheme 7 rootstocks and 2 storage periods, with four repetitions of twenty fruits.

Place and Duration of Study: The experiment was carried out at the Universidade Federal de Pelotas, Brazil. The experiment was conducted during the 2014/2015 season.

Methodology: The peach orchard used Chimarrita cultivar grafted in seven rootstocks. Evaluations were carried out at the beginning of the experiment (harvest) and after 21 days of cold storage, followed by a 3-day commercialization simulation period at room temperature. Peaches were analyzed regarding pulp browning, content of total phenols, antioxidant activity, firmness and soluble solids.

Results: Pulp browning was more intense in fruits picked from trees grafted on Tsukuba, Nemaguard, Flordaguard and Aldrighi rootstocks. Peaches with the highest content of phenolic compounds were picked from trees grafted on Okinawa on the day they were harvested and from trees grafted on Tsukuba and Flordaguard after storage. The highest antioxidant activity was found in peaches from trees grafted on Capdeboscq when they were harvested and on Nemaguard and Okinawa after storage.

Conclusion: Peach rootstocks influence phenolic compounds, antioxidant activity and soluble solids at the time of harvesting and after storage. Pulp browning was less intense in peaches picked from plants grafted on the Okinawa rootstock after cold storage followed by commercialization simulation. Phenolic compounds, antioxidant activity and firmness of peaches decreased after storage, regardless of the rootstock.   

Open Access Original Research Article

The Effect of Vinasse Application in Lowland Areas Cultivated with Sugarcane on Spatiotemporal Variability of Groundwater Salinity in the Northeast of Brazil

Wellington Pereira da Silva, Ceres Duarte Guedes Cabral de Almeida, Karina Patrícia Prazeres Marques, Gledson Luiz Pontes de Almeida, Brivaldo Gomes de Almeida

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/JEAI/2018/39561

Aims: The aim of this study was to evaluate the spatiotemporal variability of electrical conductivity in groundwater under vinasse application on a lowland area cultivated with sugarcane in the northeast of Brazil.

Place and Duration of Study: This area is located in a sugarcane/ethanol plant in Pernambuco state (Brazil) and receives an average annual rainfall of 2100 mm, between January 2011 and August 2011.

Methodology: The experiment was composed of 54 georeferenced wells spread over an area of five hectares of sugarcane crop. This sampling was carried out six times from the 54 wells during eight months to evaluate the temporal variability of electrical conductivity (EC) in the groundwater. Descriptive statistics and geostatistical methods were used for spatial modeling and to create maps. A correlation matrix using Spearman’s method was calculated by SAS to evaluate if there was a temporal correlation among the electrical conductivity values of groundwater over a long period of time.

Results: The mean EC does not present any risk of soil salinization, and do not produce a limit for irrigation. All data had normal frequency distributions. A Gaussian model was adjusted for all samplings. The range of spatial dependence was from 20.43 m 4th sampling) to 34.64 m (before vinasse application), with an average of 25.17 m. EC values in the groundwater during the monitoring period were not high enough to indicate a severe degree of restriction on use, i.e. < 3dS.m-1.

Conclusion: Groundwater electrical conductivity was reduced by rainfall events and did not present a risk of salinization. The range of spatial dependence values demonstrated that it was necessary to use 32 m spacing between observing wells for the sustainable management of vinasse in lowland areas.