Revista de la Facultad de Agronomía de la Universidad del Zulia

Biocontrol of Cosmopolites sordidus using entomopathogenic fungi under laboratory conditions, Ecuador

Sun, 30 Mar 2025 00:00:00 +0000

Cosmopolites sordidus known as the black weevil, is an insect pest of economic importance for Musaceae crops such as bananas and plantain, resulting in production losses due to its damage. One of the alternatives for the management of the black weevil is biological control using entomopathogens that regulate the insect populations in Musaceae plantations. The objective of the research was to determine the action of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Verticillium lecanii on adults of the black banana weevil under controlled laboratory conditions. A completely randomized design was implemented with 8 treatments with the application of the entomopathogens individually and in combinations, as well as a control treatment. The results showed that the treatment with the combination of B. bassiana + M. anisopliae showed the best control of the insect pest with 100 % mortality 10 days after inoculation, followed by B. bassiana with 88 % and 24% control with M. anisopliae, while the treatment with the fungus V. lecanii achieved 32 % control of the black weevil. Entomopathogens are an alternative for the management of the insect pest of Musaceae C. sordidus.

Morphological and genetic variability of chili pepper (Capsicum annuum L.) populations from northern of Mexico

Mon, 14 Apr 2025 00:00:00 +0000

This study investigated the genetic and morphological variability of five domesticated chili varieties (Árbol, Güerito, Mirasol, Negro and Alcalá) and one wild variety (chiltepín) from Chihuahua, Mexico. Morphological evaluation was carried out according to the International Plant Genetic Resources Institute, combining correspondence analyses and Chi-square tests. Genetic variability was determined using the RAPD technique; a dendrogram was constructed, and genetic diversity among populations was estimated using principal coordinate methods, Shannon index, and permutational multivariate analysis. The morphological analysis revealed significant variations, while the genetic analysis, using the RAPD technique, showed 79.5 % polymorphism, indicating considerable diversity among the varieties. The dendrogram revealed the presence of three groups, highlighting chiltepín as potential ancestor of the domesticated varieties. The study emphasizes the importance of conserving and improving these plant genetic resources.

Multivariate analysis in the characterization of feijoa fruits (Acca sellowiana [O. Berg] Burret) in Tungurahua, Ecuador

Augusto Palacios-Villacrés, Fernando Sánchez-Mora, Rubens Onofre — Mon, 14 Apr 2025 00:00:00 +0000

The feijoa (Acca sellowiana [O. Berg] Burret) is a Myrtaceae native to southern Brazil and northern Uruguay. Its fruits can be consumed fresh or processed into juice, ice cream, wine, liqueurs and others. In Ecuador, feijoa cultivation has been reported since 1980 in the province of Tungurahua. To evaluate the morphological and physicochemical characteristics of feijoa fruits through multivariate analysis, fruits from 18 farms located in Tungurahua, Ecuador were analyzed. A sample of 10 fruits per farm were analyzed in the food processing laboratory of the Tungurahua Higher Technological Institute. Descriptive statistics and multivariate analysis were employed for data evaluation. The fruits exhibited an oboval shape with erect sepals, moderate skin roughness, and white pulp. Fruit diameter ranged from 2.0 to 5.1 cm (CV=17 %), and fruit length ranged from 2.46 to 10.1 cm (CV=16.2 %), indicating variability in fruit size. Fruit biomass ranged from 8 to 133 g, with pulp yields between 4.6 % and 46.2 %. Total soluble solids ranged from 8.0 to 20 °Brix; the pH and titratable acidity (citric acid percentege) averaged 3.5 and 0.50, respectively. Fruit length and diameter showed a high correlation with fruit biomass. PCA identified the formation of three groups of producers, based on fruit size

Effect of organic and inorganic fertilization on the growth and yield of Gossypium hirsutum L. in Ecuador

Sat, 19 Apr 2025 00:00:00 +0000

The cultivation of cotton (Gossypium hirsutum L.) has a significant impact on the global economic and agricultural sectors, with its productivity being closely linked to nutrient management and the sustainability of the production system. The objective of this study was to evaluate the effect of organic and inorganic fertilization on the growth and yield of G. hirsutum in Ecuador. A completely randomized block design was used with a 2×4×2 factorial arrangement, which included two nitrogen sources (organic matter and urea), four nitrogen fertilization rates (50, 100, 150, and 200 kg N.ha^-1), and the presence or absence of efficient microorganisms (EM). Phenological, morphometric, and yield-related variables were measured, along with foliar concentrations of N, P, and K. The results indicated that urea fertilization promoted greater vegetative growth and yield, while organic matter enhanced foliar potassium uptake. The application of efficient microorganisms (EM) did not produce statistically significant differences compared to the control treatment across all evaluated variables, as it significantly increased yield. Moreover, the interaction between nitrogen sources and fertilization rates showed that the combination of 150 kg N.ha^-1 with EM optimized production. Inorganic fertilization with urea maximized cotton productivity, while organic matter contributed to a more sustainable production system, promoting sustainable agriculture.

Effect of herbicides on the growth of beneficial microorganisms in rhizospheric soil

Thu, 01 May 2025 00:00:00 +0000

This research seeks to understand the impact of herbicides on beneficial soil microorganisms, essential for agricultural health, and contribute to more sustainable management practices. The study aimed to evaluate the effect of herbicides commonly used in conventional agriculture, such as glyphosate, paraquat, and MCPA, on the growth of beneficial soil microorganisms. The microorganisms were isolated from the rhizosphere soil of a CCN-51 cacao crop from a production farm in Ecuador, and identified through morphological characterization and molecular analysis. The detected beneficial microorganisms were seeded in culture media with field-used doses of the different herbicides mentioned above, and mycelial growth in fungi (Trichoderma asperellum) and colony extension in bacteria (Bacillus subtilis and Pseudomonas fluorescens) were evaluated. The results showed that the herbicides had a significant inhibitory effect on the growth of these beneficial microorganisms. In the case of T. asperellum, paraquat and MCPA showed greater mycelial inhibition compared to glyphosate. Furthermore, all three herbicides significantly reduced the growth of B. subtilis and P. fluorescens, in contrast to the control groups, which maintained constant growth. These findings suggest that the herbicides studied may have a negative impact on the growth dynamics of beneficial microorganisms, which could affect the balance of the agricultural ecosystem. These results highlight the importance of considering the potential effects of herbicides on the soil microbiota in the management of sustainable agricultural systems.

Correlation between UAV multispectral Imagery and spectroradiometer measurements in sunflower developmental stages

Alperen Erdoğan, Ömer Mutluoğlu, Önder Gürsoy — Thu, 01 May 2025 00:00:00 +0000

Oilseed crops are among the product groups with a supply deficit in the world. The sunflower oil crisis experienced after 2020 ha increased the importance of sunflower cultivation. The most important stages in agricultural applications are to understand whether the plant is healthy in the early stages before it is formed and to prevent negative results in harvest. With the developing technology, the use of unmanned aerial vehicles (UAVs) and multispectral cameras in agricultural applications has gained enormous importance. Thanks to UAVs, agricultural temporal resolution can be adjusted according to the user's request, and spatial resolution can be adjusted according to the ability of the sensor used and the flight altitude. Spectral resolution is directly proportional to the number of bands and the band wavelength. We performed correlation analysis in this study by comparing the accuracy of the band values with ground measurements made with a spectroradiometer. We measured the sunflower in its vegetative, R-3, and R-5 phases and found that there was a strong correlation (r=0.894) in the green band, r=0.845 in the red, r=0.789 in the red edge (RE) band, and r=0.725 in the near infrared band (NIR). The results show a strong connection between the spectral bands and the spectroradiometer measurements, especially in the green and red bands.

Pathogenicity of Fusarium oxysporum f. sp. nicotinae and F. phyllophilum in tobacco in the Granma region, Cuba

Wed, 28 May 2025 00:00:00 +0000

Diseases caused by Fusarium spp. are considered cosmopolitan and affect a great diversity of crops worldwide. In the tobacco-growing areas of Granma province, located in eastern Cuba, these phytopathological problems cause significant losses in tobacco leaf yield and quality. To address this critical issue, a comprehensive study was conducted, focusing on disease monitoring and the identification of tobacco seeds and seedlings (cv. Corojo 2012) affected by the diseases. The study also examined the variables associated with the severity of the diseases. The results of the study indicated that the vascular wilt was caused by two distinct fungal pathogens: F. oxysporum f. sp. nicotinae and F. phyllophilum. The study revealed that the disease exhibited levels of recurrence in both space and time, reaching up to 62 % necrosis in seedlings with no chance of survival. This disease severity, measured on a maximum scale of five, attained a maximum score of 4.20. The findings indicated a substantial inhibition in the germination and growth variables of Nicotiana tabacum, which has a profound impact on the yield and commercial quality of N. tabacum leaves, particularly those intended for the Cuban cigar manufacturing industry. This underscores the necessity for expeditious diagnosis of the disease and the implementation of appropriate management strategies to mitigate the risks of its propagation in producing regions of Cuba and globally.

Antimicrobial activity of Cymbopogon schoenanthus essential oil extracted by a solar distillation system

Zineb Safa, Ahmed Boulal, Khawla Zahra Hadef, Katia Djenadi — Wed, 28 May 2025 00:00:00 +0000

Cymbopogon schoenanthus (L.) Spreng is an aromatic medicinal plant that grows in Algeria. It is commonly called camel grass and known by the local name "Lemmad." Traditionally, it has been used to treat diverse diseases. Therefore, this study aimed to evaluate the antimicrobial activity of the essential oil of Cymbopogon schoenanthus (EOCS), grown in Timiaouine, Algeria, A solar distillation (SD) system was used to extract the oil. This extraction occurred in June 2023. Subsequently, the physical properties were determined. The antimicrobial activity against four bacteria and one yeast was evaluated using the agar diffusion test. Various dilutions were used, and the inhibition zones were measured to determine the extent of antimicrobial activity. In this study, the yield was estimated to be 0.97 %, with a density of 0.8490 and a refractive index of 1.4850. The antimicrobial properties of this essential oil (EO) showed efficacy against Escherichia coli (EC) and Klebsiella pneumoniae (KP) at dilutions of 1/3 and 1/4, with inhibition diameters varying between 15 to 9 mm. On the other hand, other strains showed resistance throughout all dilutions. This research indicates that the EOCS extracted using the SD process has effective antibacterial properties against Gram- bacteria. Moreover, Additional research is required to clarify and assess the effects of the chemical composition, thereby enhancing our understanding of the underlying mechanism.

Agronomic performance and industrial quality of bread wheat (Triticum aestivum L.) genotypes cultivated in the northeast of Mexico

Wed, 28 May 2025 00:00:00 +0000

Wheat is one of the main crops worldwide, it is distributed in different climatic, ecological and geographical regions around the world, being a basic food for human nutrition. The search for genotypes that have to different environments is a common practice in agriculture. The objective of this study was to evaluate the agronomic performance and industrial quality of four genotypes of bread wheat (BW), namely, BW1 (Control) (San Isidro NL M-2012), BW2 (Floreña NL M-2012), BW3 (Norteña F2007), and BW4 (Conatrigo F2015). Wheat genotypes were evaluated using a complete randomized block design with four replicates. Based on results, BW4 (Conatrigo F2015) had better agronomic performance with higher results in spike length (11.10 ± 0.38), number of spikelets per spike (18.78 ± 0.91), number grains per spike (55.65 ± 7.13), grain yield per hectare (6.42 ± 1.29), forage per hectare (12.25 ± 1.30), and L* in the flour (88.74 ± 0.15). BW4 (Conatrigo F2015) also had the lower weight loss (10.15 ± 1.30) and the higher L* in crust (68.55 ± 0.09). In conclusion, genotypes evaluated in the present work had similar or better results in most of the agronomic performance and industrial quality compared with BW1 (Control) (San Isidro NL M-2012), being BW4 (Conatrigo F2015) the outstanding genotype.

Identification of indole acetic acid biosynthesis pathways in Trichoderma asperellum and Trichoderma koningiopsis

Mon, 02 Jun 2025 00:00:00 +0000

Trichoderm spp. produces secondary metabolites associated with plant growth promotion, especially the production of indole acetic acid (IAA), the main plant hormone. The tryptophan-dependent (TRP-D) and tryptophan-independent (TRP-I) production pathways, depending on the precursor involved in IAA synthesis, are well known. The objective of this study was to investigate the tryptophan-dependent (TRP-D) production pathway under in vitro liquid culture conditions (Potato Dextrose), supplemented with tryptophan (TRP). The presence of auxinic compounds in TRP-D was quantified using high-performance liquid chromatography (HPLC). Additionally, the morphology of corn seeds was analyzed using scanning electron microscopy (SEM). The interaction of Trichoderma spp. with corn seed germination was evaluated under controlled laboratory conditions, conducting the assay in triplicate and performing an analysis of variance (ANOVA). The results showed that the species T. asperellum and T. koningiopsis can degrade TRP and synthesize IAA through the tryptamine (TRM) and indole acetamide (IAM) pathways. However, IAA synthesis was not detected through the indole pyruvic acid (IPyA) and 3-indole acetonitrile (IAN) pathways. In particular, T. asperellum produced significantly higher concentrations of IAA compared to T. koningiopsis. Additionally, it was observed that tryptophan supplementation increased IAA production in both species. Finally, T. koningiopsis showed a strong relationship with the maize root system, invading the root and establishing a beneficial interaction that could contribute to plant growth and development. These findings suggest that T. koningiopsis has significant potential as a biofertilizer in agricultural systems.

Local grape cultivars in Egypt: exploring their potential health benefits

Abeer Dahab, Rania Mahmoud, Hemat Abd El-Salam, Gehan Mahmoud, Eman Ibrahim — Tue, 20 May 2025 00:00:00 +0000

The biological activities of phytochemical compounds in grapes have recently attracted increasing attention due to their potential health benefits for humans. In this study, seven local grape cultivars of Egypt (Gharibi, Fayoumi, Bez El-Naka, Romy Ahmer, Edkawy, Matrouh Eswid and Baltim Eswid) were investigated to determine their phytochemical composition, antioxidant and antimicrobial activities. Tannins, total phenols, total flavonoids and resveratrol content of grape pulp and seed extract were measured. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and the ferric reducing antioxidant power (FRAP) assays were used to determine the level of antioxidant activity. Polyphenolic compounds were identified using Liquid Chromatography-Tandem Mass Spectrometry Technique (LC-MS/MS). The findings revealed that, the Edkawy and Baltim Eswid cultivars presented the highest content of tannins in the seeds (0.68 and 0.65 %, respectively), and total flavonoids in the pulp and seeds (0.06 and 0.08 %, respectively). Baltim Eswid showed the best total phenols content (0.11 %) in the pulp. Overall antioxidant capacity of grape seed extracts was extremely superior to that of the pulp, where Baltim Eswid was the best in this concern. The maximum values of resveratrol for pulp and seed (46.24 and 307.12 mg.100g^-1, respectively), were observed in Baltim Eswid. The main compounds found in the seed extract were the catechins, ranging from 26.51 % in Fayoumi to 35.8 % in Bez El-Naka. The study demonstrated that grape seed extract has antimicrobial properties with potential application as an antimicrobial agent in the industrial area and as an alternative treatment in the medical sector.

Potential of Citrullus lanatus seeds as a natural coagulant in drinking water treatment

Sedolfo Carrasquero, Altamira Díaz, María Pire — Tue, 20 May 2025 00:00:00 +0000

Natural coagulants have received significant attention due to their biodegradable nature, cost-effectiveness, and abundance of sources. The objective of the research was to analyze the efficiency of Citrullus lanatus seeds treating synthetic waters with three levels of initial turbidity (13, 75, and 200 NTU), applying four rapid mixing times (1, 2, 4, and 5 min) in the purification process. The coagulant was prepared with 5 g of the seed previously ground, sieved, defatted, and diluted in a volume of 1 L of distilled water. Jar tests were performed using doses of 50, 70, 90, 100, 150, 200, 250, 300, 400, and 500 mg.L^-1 using true color and turbidity as control parameters. The coagulation was performed at a speed of 100 rpm, while flocculation lasted 20 minutes at 30 rpm, and the resting phase was 30 minutes. It was obtained that the optimal doses of C. lanatus in the treatment process were 50, 150, and 300 mg. L^-1 for waters with 13, 75 and 200 NTU, respectively, obtaining the highest percentages of turbidity removal (96.6%) and true color (94.4%) in water with 75 NTU. Furthermore, it was concluded that increasing the time in the rapid mixing phase caused an increase in the levels of turbidity and true color; being the time of 2 min the one that generated water that meet the values desired by the current Venezuelan drinking water regulations, which contemplates 1 NTU for turbidity and 5 UC Pt-Co for true color.

A systematic review of COVID-19 effects on agri-food chains in Latin America

Thu, 01 May 2025 00:00:00 +0000

The rise of the COVID-19 pandemic generated large effects on global supply chains. These effects are especially relevant in agriculture, as they compromised food security. The present study is a systematic review of peer-reviewed scientific literature to understand the effects of the pandemic on agro-food chains and links in Latin America. The documented effects are mainly negative (81.5 %) and translated into impacts on production systems (32.3 %) and markets (24.6 %). It was reported that the impacts on production were due to difficulties in labor mobility, interruption of the supply chain, closure of external markets and increased transportation costs. Transportation was the link with the most difficulties due to restrictions on mobilization, even though it was the least referenced. There were negative impacts on processing, due to the shortage of raw materials and the interruption or closure of industries. On the other hand, some positive effects were reported, such as the development of local markets, the emergence of alternative products and digital markets with direct home delivery, as well as a shift towards healthy consumer habits. Agricultural policy makers should take these results into account when proposing strategies to develop more resilient agrifood chains to face challenges such as those caused by the Covid-19 pandemic.