Journal of Agricultural Science

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ISSN / EISSN : 1916-9752 / 1916-9760
Total articles ≅ 3,757
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Robai N. Liambila, John M. Wesonga, Catherine N. Ngamau, Waudo Wallyambilla
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p86

Abstract:
Studies examining the variability in wild plant metabolic expression propose that environmental factors significantly influence the essential oil (EO) quality and quantity in a plant. Lantana camara is a widely distributed invasive plant species worldwide. However, its immense metabolites can become a source of novel compounds to produce biopesticides in the agricultural industry. Although, the quality aspect has to be considered due to the environmental influence on the metabolites synthesised. Therefore, this research aimed to understand the influence of environmental factors and how it shapes the plant’s metabolite profile in multiple populations of L. camara. Leaf samples were collected from six different geographic regions of Kenya and the corresponding monthly climatic data and soil samples. GC-MS data from leaf EO were analysed with environmental variables (climate and soil data) using unimodally unconstrained and constrained ordination methods for untargeted metabolomics analysis. Partial Least Squares-Discriminant Analysis (PLS-DA) and Random Forests (RF) were used to confirm the variability further. Seasonal and regional variability was observed for secondary metabolites (SMs) in the leaf EO, which correlated to climatic factors and soil attributes. We highlight the season-al-geographic metabolism relationship for L. camara and the combined analytical approach to obtain data that contributes to understanding the influence of environmental factors on the synthesis and accumulation of SMs. This research will have all-embracing implications for maximising phytochemical uniformity.
Erlei Melo Reis, Wanderlei Dias Guerra, Andrea Camargo Reis, Mateus Zanatta, Marcelo Carmona, Francisco Sautura
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p141

Abstract:
Multisite fungicides have been used for many years in fruit and vegetable crops worldwide. Cases of the fungi resistance development to these fungicides have been rare. From the 2002 season onwards, with the outbreak of Asian soybean rust in Brazil, caused by Phakopsora pachyrhizi, site-specific fungicides became the main weapon for its control. From 2002 to 2011, penetrant mobile site-specific fungicides were used and until today in double (DMI + QoI) or triple (DMI + QoI + SDHI) co-formulatoons in an area of more than 30 million hectares and with three sprays per area. This resulted, as expected, in the fungus sensitivity reduction, today with cross and multiple resistance to those site-specific fungicides. From the 2011 season in an attempt to recover control that for some chemicals and mixtures reached < 30%, research was started with site-specific + multi-site mixtures, taking as example Phytophthora infestans resistance development to metalaxyl in Europe showinig long-lasting solution found by the addition of multisite mancozeb. It is expected that the effective life of site-specific + multi-site mixtures may be as long in controlling soybean rust as it has been for potato, tomato and grape downy mildews. This review presents the concepts involved in the sensitivity reduction to fungicides. Some fungal species and fungicides involved are listed. Considering the P. pachyrhizi sporulation potential, the great soybean area sprayed and the number of sprays per area mainly with site-specific co-formulations and the reduced area sprayed with multisites, we discuss the need for annual monitoring of P. pachyrhizi sensitivity to the these chemicals.
Amanda Maria de Sousa Diogenes Ferreira, Francisco De Assis Oliveira, Steel Silva Vasconcelos, José Renan Da Silva Guimarães, Luciedi De Cassia Leôncio Tostes, Francisco Oliveira Cruz Junior, João Da Luz Freitas, José Victor Torres Alves Costa, Angela Maria Braga Lobato, Adriano Castelo dos Santos
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p105

Abstract:
This study was part of the Manipulation of Moisture and Nutrient Availability in Young Regrowth Forests in Eastern Amazonia Project (MANFLORA). The experiment was designed in completely randomized blocks containing control and irrigated treatments during the dry period (5 mm of water/day), with four repetitions each. The monthly mean litter values ranged from 316.10 to 997.90 kg ha-1 month-1. The magnitude of this phenomenon can be explained by the functional role of the floristic structure, represented by the species Myrcia sylvatica (G. mey) DC., Myrcia bracteata (Rich) DC., Miconia ciliata (Rich) DC., Lacistema pubescens Mart., Lacistema aggregatum (Berg.) Rusby, Vismia guianensis (Aubl.) Choisy, Cupania scrobiculata Rich. and Ocotea guianensis Aubl., which constituted the determinant factors, associated with the hydroperiodic effect and ecosystem manipulation. The monthly mean of the analytical results of mass treatments were significant (P < 0.05), however, when compared annually there was no significance, which indicates seasonal influence, since the period of greatest deposition is the dry one, regardless of the water manipulation along the period studied. Only in time the mass values of Ca and Mg were not significant for treatment (P < 0.05). The amount of Ca was significantly (P < 0.05) higher than that of Mg.
Teomar Duarte da Silva, Michele Trombin de Souza, Mireli Trombin de Souza, Roger Raupp Cipriano, Humberto Ribeiro Bizzo, Cicero Deschamps
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p23

Abstract:
The restinga is an Atlantic Forest ecosystem characterized by tree, shrub, and herb species that are rich sources of essential oils. In this study, we aim to quantify the essential oil content and determine the chemical constituents of fresh leaves of 14 plant species in a restinga stretch in southern Brazil. Essential oils were obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by gas chromatography coupled to mass spectrometry. Campomanesia reitziana, Cortaderia selloana, and Sophora tomentosa had no essential oils. Total essential oil content ranged from 0.01% (Mikania involucrata) to 1.56% (Varronia curassavica). In total, 60 chemical constituents were identified, representing between 46.2% and 96.5% of the chemical composition of the essential oils. Limonene was the common constituent in all species in which the essential oils were present. The major constituents were ar-curcumene (15.1%) and cis-chrysanthenol (14.2%) in Ambrosia elatior; benzyl benzoate (43.5%) and benzyl salicylate (23.7%) in Aniba firmula; caryophyllene oxide (35.7%) and spathulenol (10.6%) in Austroeupatorium inulaefolium; spathulenol (19.8%) and caryophyllene oxide (14.0%) in Baccharis spicata; caryophyllene oxide (16.3%) in Eugenia astringens; curzerene (30.0%), limonene (13.0%), and germacrone (11.9%) in Eugenia uniflora; caryophyllene oxide (17.1%) and ledol (11.3%) in Lantana camara; caryophyllene oxide (27.7%) and limonene (12.7%) in M. involucrata; 1,8-cineole (19.8%) in Psidium cattleianum; limonene (10.2%) in Schinus terebinthifolius, and allo-aromadendrene (15.2%) in V. curassavica. We expect that our results can assist in selecting species of potential interest for herbal, phytotherapeutic, and cosmetic products.
Esther Gloria Mbabazi, Enoch M. Kikulwe, Joseph Lule Kyanjo, Nasser Mulumba, Edward Kato, Elisabetta Gotor
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p11

Abstract:
The livelihoods of millions of banana-farming households have been affected by Banana Xanthomonas Wilt (BXW) in Uganda for nearly two decades. The disease has no known cure, all banana cultivars grown are susceptible to it and it is endemic in all banana-producing regions in the country. This study analysed the long-term impact of the disease on the livelihoods of banana-producing households. Using a balanced panel dataset of 1,056 households, which were visited in 2015 and revisited in 2018, provides the opportunity to empirically measure the long-term consequences of the disease on farmers’ economic wellbeing in the four major banana growing regions in Uganda. We find striking results pertinent to disease incidence, success in disease management, household income and poverty when deploying BXW control practices. Although the disease has remained present in farmers’ fields, there is a significant reduction in household poverty levels. Results show that some farmers expanded the production of beans and coffee without encroaching on their banana plantations. Increase in bean production was largely through intercropping. Investment in coffee was constrained by land ownership, hence only a viable venture for the wealthy farmers who own bigger pieces of land. Land-poor farmers continued to rely on bananas for their livelihoods. Consistent participation in disease management training significantly influenced adoption of the cultural control practices. Consequently, farming households that systematically adopted these practices were able to maintain low levels of disease incidence, improve productivity by 438 kg/ha/year and increased their daily and annual household income by US$1.75 and UGX 2.383 million (US$648), respectively. The findings suggest that banana is an important crop to smallholder farmers and expansion into other cash crops requires bigger resource outlays, and that despite continued exposure to BXW, farmers’ income increased over time. Farmers should continuously and systematically use the recommended control practices to avoid BXW resurgence and, consequently, a reduction in their income.
Benjamin Adon, Jean Noel Konan, Benoît Cochard, Albert Flori, Sekou Diabaté, Claude Bakoumé, Didier Paulin Sokouri
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p64

Abstract:
In Côte d’Ivoire, Deli populations, descendants of four oil palms, constituted Group A of the recurrent reciprocal selection. Their genetic base was narrow, an obstacle to long-term genetic progress. Therefore, Angolan oil palm accessions were acquired to broaden Group A’s genetic base. Angola selfed and Deli × Angola progenies were tested via Angola selfed × La Mé and (Deli × Angola) × La Mé intergroup hybrids for bunch and oil production, height growth, and tolerance to Fusarium in two progeny trials; one in La Mé (Côte d’Ivoire) and the other one in Bangun Bandar (Indonesia). On average, bunch yield (183 kg/palm/year) and oil yield (5.34 t/ha) were close to those of the control. The best 5 hybrids represented 104-112% of the control all traits put together. In addition, Angolan origin has transmitted tolerance to Fusarium to its progenies (Fusarium index = 80-90). [(Deli × Angola)’s LM 5448 T] × La Mé hybrids yielded 241.4 kg/palm/year of bunch and 7.30 t/ha of palm oil. Their mean height was comparable to that of the control and the Fusarium index low (82). Therefore, LM 5448 T was selected for further crop improvements. The modalities of its use were proposed.
Erlei Melo Reis, Wanderlei Dias Guerra, Laércio Zambolim, Fernando C. Juliatti, José Otávio Menten, Mateus Zanatta, Luana Maria De Rossi Belufi
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p127

Abstract:
The objective of this work was to assess the effect of December sowing time with February on the Asian soybean rust severity. In on-farm trials two soybean treatments sowing in December (2020) (DSS.) and February (2021) (FSS) were assessed for Asian soybean rust severity in 24 sites, in three regions of Mato Grosso state. The DSS treatment was established in the growers commercial farms and the FSS in a 5 ha area sown specifically for this treatment. The DSS treatment was conducted in 16 sites and the FSS in eigth. For rust control fungicides with efficacy higher than 60% were sprayed consisting of DMIs, QoIs and SDHIs in double or triple mixtures, always added by multisites (chlorothalonil, mancozeb, or copper oxychloride). About eighty soybean leaflets from four plots repetitiond, demarcated at random in each field, were taken in each smpling. In laboratory leaflet severity was appraised and area under disease progress curve (AUDPC) calculated. Related to DSS, the AUDPC overall mean was 174 units and receiving 6.9 fungicide spraying and for FSS 26 units with 4.8 fungicide sprayings. Our results reinforce that the sowing time can be changed from the end of December to February to maintain soybean crop sustainability.
Kun-Jun Han, Kenneth A. Albrecht
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p1

Abstract:
Cup plant (Silphium perfoliatum L.) may serve as an alternative perennial forage crop in lowlands of the north central United States. Three feeding trials were conducted with Holstein cows (Bos taurus) at the early, mid, and late lactation stages to evaluate the impact of different cup plant silage substitution levels for alfalfa (Medicago sativa L.)-corn (Zea mays L.) silage mixture on milking cow performance. The concentrations of lignin and CP (crude protein) in the first cut and regrowth cup plant silage were lower than alfalfa silage. Substituting one-half of the silage reduced voluntary dry matter (DM) intake of early lactation stage cows by 11%. Although milk composition was not changed by the substitution, the 4% FCM (fat corrected milk) production was reduced by 7.5%. Another feeding trial tested substitution of one-third and two-thirds of the silage for mid-lactation cows. Increasing cup plant silage up to two-thirds of the forage portion in the diet reduced DM intakes and 4% FCM production by 21.8 and 8.7%, respectively. Milk composition did not change. Cow bodyweight was reduced as the substitution rate increased. Finally, a feeding trial with late-lactation cows indicated substitution of one-fourth of the silage performed equivalent in DM intake, milk composition, and milk production to those of cows fed a low forage diet (50% alfalfa-corn silage in diet), or a high forage diet (66% alfalfa-corn silage in diet). Based on the results of the three feeding trials, it is concluded that cup plant silage can substitute mixture of alfalfa-corn silage at up to 30% of the forage portion in diets without substantial negative impacts on the performance of dairy cows, especially during late lactation.
Anne Brown
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p167

Abstract:
Reviewer acknowledgements for Journal of Agricultural Science, Vol. 13, No. 11, 2021.
Selorm Omega, Alexander T. K. Nuer, Enoch Ametepey
Journal of Agricultural Science, Volume 13; https://doi.org/10.5539/jas.v13n11p153

Abstract:
Coronavirus 2019 is a global health concern that has left most countries in a state of severe economic meltdown. Scientific research has been down on the virus and its impact on various sectors but that of the Nigerian aquaculture industry has been missing. This paves the way for this research to aim at bridging this gap by looking at the perception of fish farmers on the influence of coronavirus on their activities, the challenges they face during the period of the virus, and the coping strategies adopted to mitigate the impact of the virus. The research used cross sectional survey design with the sample size being 11 fish farmers living in Oyo state, Nigeria. Homogeneous purposive sampling was used and primary data collected through the use of google form. The data collected was analysis using SPSS version 25.0. The result of the analysed data showed that: on socioeconomic characteristics; the majority of the respondent reported that Coronavirus has had an effect on their fishing activity and they were mostly small scale farmers with catfish being the predominate fish farmed. The majority of fish farmers perceived demand decline, high cost of production, fish being more expensive, and reduction of manpower on the farm due to lockdown measures. Reduction in walk-in customers to the farm was revealed as the major challenge posed by the pandemic, while the inability to get technical support as least. On coping strategies adopted, it was revealed that farmers have resorted to the development of their own feed.
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