Revista de Ciencias Agrícolas

Optimizing artisanal plastic traps for monitoring and managing banana weevils: color, odor, and position

2024-11-05T03:23:36+00:00

Banana weevil, Cosmopolites sordidus (Germar), and striped weevil, Metamasius hemipterus (Linnaeus), are pests of global importance in banana cultivation that are traditionally controlled using synthetic insecticides. Plastic traps offer an alternative method to managing these weevils. However, the effectiveness of artisanal traps, considering color, odor, position, and their influence on trapping efficacy, has been largely neglected. Here, we assessed artisanal plastic traps for capturing banana weevils, testing two trap colors (yellow and brown), two positions (horizontal and vertical), and five types of attractants: pineapple; pineapple combined with molasses; pseudostem; pseudostem combined with molasses; and the pheromone Cosmolure in Ecuadorian banana fields. Under controlled conditions, trap color and position did not significantly influence the preference for C. sordidus and M. hemipterus (P<0.05). Field bioassays revealed significant differences in the capture of C. sordidus based on trap position and odor attractants. While trap position did not affect the capture of M. hemipterus, the choice of attractant influenced insect capture rates. Cosmolure was the most effective attractant for capturing banana weevils, whereas pineapple baits attracted the highest number of stripped weevils. Over 10 days, the number of captured insects decreased for both weevils across different attractants. Our findings highlight the potential of artisanal plastic traps as a valuable tool for the integrated pest management (IPM) of C. sordidus and M. hemipterus in banana plantations.

Factors influencing the acquisition of corn seed in the State of Veracruz, Mexico

2024-06-25T20:07:13+00:00

Corn production is a fundamental agricultural activity in Mexico. However, producers face significant challenges in accessing improved seeds that can optimize yields. Identifying the factors influencing the acquisition of these seeds is crucial for developing effective support strategies for local farmers. This study aimed to analyze the factors affecting the acquisition of improved corn seeds in three communities within the municipality of Paso de Ovejas, Veracruz, Mexico. A survey method and semi-structured interviews were conducted with 103 producers. Agricultural technicians and neighboring farmers were identified as the primary sources of information on seed use. Economic and social factors were found to have the greatest influence on access to information. Hybrid seeds from transnational companies, such as Monsanto and Pioneer, dominated the market, accounting for 83% of seed purchases. These seeds were more expensive than those from national companies, with an average cost of $5,728 per producer. Economic factors were determined to be the most significant influence on the purchase of improved seeds, outweighing social,
political, and human factors.

Effect of Acacia mangium Willd plantations on the natural regeneration of a savanna

2024-03-19T20:35:55+00:00

Introducing alien species into natural ecosystems can generate important changes in water quality and supply level, ecosystem services, and biodiversity. Different results have been found with the appearance of alien species that contemplate both high invasion risks and opportunities to form new ecosystems that permit a new path toward restoration. This research aimed to analyze the contribution of Acacia mangium Willd. plantations for ecological restoration using both spectral instruments and conventional sampling to calculate the abundance or frequency of species appearances. Two analyses were conducted on four plant covers (an active plantation, a felled forest, and a gallery forest edge). The analysis was of a spectral type, evaluating two vegetation indices and their relationship with the Berger-Parker biotic dominance index (D); the vegetation indices were NDVI (the normalized difference vegetation index) and CVI (the chlorophyll vegetation index). The statistical methodologies involved spatial regression modeling to relate diversity and spectral indices and a permutational multivariate analysis of variance for the variables associated with regeneration. We found that felled plantations have a higher degree of similarity to gallery forests in terms of spectral indices and diversity when compared to active plantations. The composition and abundance of species of natural regeneration in plantations differ significantly from both regeneration in forests and regeneration in savannas.

Net primary productivity in a Tropical Dry Forest of northern Colombia

2024-01-22T21:20:11+00:00

Tropical dry forests are the world’s second most relevant forest type, home to unique vegetation and highly threatened by human activity. This study aimed to determine changes in plant biomass within a tree-hectare permanent plot of tropical dry forest (TDF) at the Universidad del Magdalena over 12 months. The composition, structure, and plant dynamics were characterized using drone imagery and allometric equations for dry climates. Biomass was calculated for 848 trees and shrubs with a diameter at breast height (DBH) over 10 cm, and a Normalized Difference Vegetation Index (NDVI) time series was established. It was possible to identify the change in NDVI with a positive trend in areas with higher soil moisture, higher coverage, vegetation network, and limited access. Likewise, the findings show that areas with lower coverage have greater accessibility and lower diversity. The vegetation cover dynamics within the Universidad del Magdalena’s TDF plot revealed low variability in NDVI over the study period, with values exceeding 0.7 in 58% of observations, reflecting a linear trend with the rainy seasons. Estimating the vegetal cover biomass is feasible using differentiated indices and techniques that reduce costs and time and do not have destructive implications for the vegetation.

Phenology, mass accumulation patterns and growing degree days in common bean

2024-10-04T18:18:17+00:00

The common bean represents approximately half of the global production of leguminous grains. Brazil is the world's largest producer, as it is a primary source of protein in the population's diet. This research aimed to relate the phenological stages of the common bean under greenhouse conditions and establish a connection between mass accumulation patterns and the environment, specifically temperature, by estimating Growing Degree Days (GDD) during two periods with different temperatures throughout the year. Once a week, after seed germination, plants were collected and weighed to quantify fresh and dry mass to determine biomass allocation within the plant. This procedure was carried out until the plant’s growth cycle was completed. The environment was systematically monitored using a thermo-hygrometer. GDD accumulation was estimated for the phenological stages from V0 to R8 during two evaluation periods. Fresh and dry mass accumulation was fitted to logistic models that generated sigmoidal-type curves. It was observed that the bean plants accumulated 803.5 GDD in the first period and 808.6 GDD in the second period, from V0 to R8, with different fresh and dry mass accumulation patterns in various plant organs. This demonstrates the relationship between temperature and the growth and development of the bean plant and can provide important information for selecting the optimal planting time for this significant crop.

Antimicrobial and molecular resistance profiles of bacterial isolates from poultry production environment

2024-06-18T19:52:34+00:00

Poultry farming is a relevant industry in Brazil, providing essential animal protein. However, such commercial activity faces significant challenges from bacterial-based diseases, which can impact both animal health and quality product. In this context, this study aimed to identify bacterial strains and evaluate their antimicrobial resistance profiles in poultry farms in southern Tocantins, Brazil. Samples were collected from different stages of poultry production, and the antimicrobial susceptibilities were assessed through antibiogram tests, where bacterial isolates were exposed to 17 antibiotics commonly used in bacterial infection treatment. Bacterial isolates were identified by 16S rRNA gene sequencing, and phylogenetic analysis was used to group them based on genetic similarities. Five isolates were identified: Glutamicibacter creatinolyticus (IGA1), Enterococcus gallinarum (IGA2), Enterobacter mori (IGA3), Lysinibacillus fusiformis (IGA4), and Enterococcus faecalis (IGA5). Antibiotic susceptibility tests revealed significant variations in resistance profiles, with some isolates exhibiting multidrug-resistant (MDR) phenotypes. IGA1 was classified as multidrug-resistant, showing resistance to imipenem, meropenem, ceftazidime, trimethoprim, and doxycycline. IGA2 exhibited resistance to β-lactam antibiotics, including ceftazidime, cefepime, doxycycline, imipenem, meropenem, piperacillin-tazobactam, and tetracycline. IGA3 was resistant to aztreonam and trimethoprim, while IGA4 showed resistance to ceftazidime and cefepime but sensitivity to ciprofloxacin and linezolid. IGA5 did not show resistance to any of the tested antimicrobials. Collectively, our findings highlight bacterial diversity and antibiotic resistance in poultry fams, reinforcing the need for continuous monitoring and effective antimicrobial control strategies to promote animal health, ensure food safety, and prevent the transmission of multidrug-resistant bacteria to humans.

Standardized rearing process of the black soldier fly (Hermetia illucens) under marginal conditions for bioprospecting purposes

2024-03-12T20:53:53+00:00

There is growing interest in large-scale breeding of black soldier fly (BSF) larvae due to their ability to consume a wide variety of organic materials. This study aimed to standardize the key developmental phases of Hermetia illucens within a rearing unit under marginal conditions (2160 meters above sea level; Temperature 14 °C average annual precipitation of 1800 mm) in an Andean Temperate Forest ecosystem. The primary objective was to optimize the production of 5-day-old larvae. A subdivided plot design was employed, incorporating two cage types, three attractants types, two glasses and three egg-laying sites, with three replicates for each combination, resulting in a total of 108 experimental units. The following factors were compared: cage type (Zurbrügg type cage and a cage proposed by the University of Caldas), attractant (organic waste, fermented waste, and a mixture containing 100 grams of dead black soldier fly adults), drinkers (cotton and sponge) and egg-laying sites (three different dimensions (A: 45 cm x 12 cm x 7 cm, B: 24 cm x 7 cm x 3 cm, and C: 12 cm x 1.2 cm x 0.5 cm)The combination of the University of Caldas cage, sponge drinkers, and the type C attractant yielded the most promising results in terms of egg weight and projected larval population size under the specific marginal conditions of the study area. The findings of this study will help to promote strategies to transform organic waste using BSF larvae in marginal conditions.

Impact of colored shade netting on growth and physiological traits in avocado creole rootstock seedling

2023-10-25T16:35:58+00:00

Photoselective netting is well-known for filtering the intercepted solar radiation and affecting light quality. However, more information is needed about how horticulture manipulation of light quantity and quality affects avocado rootstock seedlings' growth and physiological traits. Therefore, this study aimed to investigate the effects of colored shading on the growth and development of avocado creole for planting production. A completely randomized experimental design with four treatments and five repetitions was used. The treatments included colored nets (red, black, white, and control – without a net). Net shading treatments affected leaf number, leaf area, leaf area index, rootstock diameter and length, dry matter, Dickson quality index, and all gas exchange variables. In contrast, specific leaf area and root length were not affected by the colored net. The red net generally increased the rootstock diameter and length, Dickson quality index, and net photosynthesis and water use efficiency more than the black, white net, and full sunlight growth conditions. This study reveals that changing the light intensity allows rootstock growth and physiological performance to be manipulated using different colored shade nets.