Scientia Agropecuaria

Integración de VANT-LiDAR con imágenes multiespectrales para la estimación del carbono almacenado en plantaciones forestales de Prosopis sp.

2025-05-05T12:17:56+00:00

Los individuos del género Prosopis sp. conocidos como algarrobos; son especies claves en el desarrollo del bosque seco y recuperación de áreas degradadas en la Costa norte del Perú. La evaluación de plantaciones, cálculo de la biomasa aérea forestal (BAF) y carbono almacenado representa un papel importante en el manejo forestal y mitigación del cambio climático. Este estudio evalúa metodologías de monitoreo a través del uso de imágenes multiespectrales y LiDAR acopladas a un VANT, con la finalidad de realizar su validación y generar modelos que permitan estimar el carbono almacenado. Se evaluaron siete especies de Prosopis sp. con la metodología convencional y se encontraron diferencias significativas entre las especies para las características dasométricas e índices de vegetación, así como en la comparación con los datos obtenidos con el LiDAR. Se seleccionaron modelos para determinar BAF y la asociación entre el carbono aéreo obtenido con los modelos constituidos por datos de LiDAR e índices de vegetación que presentaron correlaciones significativas (p < 0,05), se construyeron siete modelos para predicción de carbono y destaca el modelo que tiene como variables regresoras la altura total y área de copa obtenidas del LiDAR, así como los índices CIgreen, GNDVI, RECI, LCI y NDVI (R² = 0,77). Lo cual confirma que el uso de la metodología LiDAR con los índices de vegetación permite una estimación más práctica del carbono almacenado en la plantación.

Antioxidant activity and seed vigor in germination of bean under salt stress conditions

2025-05-05T12:59:54+00:00

Using seeds with higher physiological potential can help overcome saline stress, affecting many arable areas in tropical and subtropical regions. This study aimed to evaluate whether seed vigor contributes to overcoming saline stress, seeking to identify the association between the antioxidant system and seed lot vigor. Seeds of the BAF55 genotype with two levels of vigor were used. The seeds were germinated under no-stress conditions, with 75 and 150 mmol L^-1 of sodium chloride in the solution during germination. After five days, morphological changes and changes in the enzyme’s catalase, ascorbate peroxidase, guaiacol peroxidase, proline, malondialdehyde, and hydrogen peroxide were evaluated. An increase in antioxidant activity was observed with the imposed stresses and no significant difference was observed between the vigor level, except in the condition of 75 mmol L^-1 in the hypocotyl of the seedlings and, for proline in the condition of 150 mmol L^-1 in which the low-vigor presented greater activity. The stress of 150 mmol L^-1 showed greater severity in seeds of low-vigor, resulting in greater lipid peroxidation in the seedlings formed and resulting in seedlings with lower performance.

Impact of Pseudomonas aeruginosa, white fungus waste, and nano fertilizer on pyrophosphatase activity, growth characteristics, and yield of stevia plant

2025-05-05T13:45:22+00:00

Aimed to know the effect of Pseudomonas aeruginosa bacteria, white fungus waste, and nano fertilizer on the pyrophosphatase enzyme, growth characteristics, and yield of stevia plants. The bacterial vaccine represented the first factor. It was added at two levels: B0 (without inoculum) and B1 (injecting 2 ml of liquid bio-inoculum represented by P. aeruginosa). The second factor was adding white fungus waste at three levels defined by Ab0 (without adding white mushroom waste), Ab1 (adding white mushroom waste at level 5 tons/h), and Ab2 (adding white mushroom waste at level 10 tons/h). Nano fertilizer was added as a third factor at four levels: N0 (without adding nano fertilizer), N1 (adding 4 kg/h of nano zinc), N2 (adding 2 kg/h of nano boron), and N3 (adding a mixture of 1 kg/h of nano boron + 2 kg/h of nano zinc). The triple combination B1Ab1N3 achieved a significant superiority in the activity of the pyrophosphatase enzyme in the first and second harvests and recorded (260.67 and 166.00) µg PO₄^-3-P/g soil 5/h, respectively, compared to the treatment without addition, which recorded (55.00 and 44.67) µg PO₄^-3-P/g soil 5/h, respectively. In contrast, the triple combination B1Ab2N3 achieved the highest growth and yield characteristics of the stevia plant and recorded the highest rate of plant height, dry weight of leaves and total yield, and recorded 83.90 and 76.00 cm/plant, 61.7 and 53.0 g/plant, 4933 and 4240 kg/h, respectively, compared to the treatment without addition, which recorded 68.98 and 60.63 cm/plant, 44.6 and 38.1 g/plant, 3563 and 3050 kg/h respectively.

An effective disinfection protocol for contamination control in vitro establishment of Mortiño (Vaccinium floribundum Kunth) and identification of endogenous microbes

2025-05-25T13:09:55+00:00

The Vaccinium genus consists of a variety of berries with high nutritious components consumed worldwide leading to the development of micropropagation protocols to supply the demand. Mortiño, the Andean Blueberry (Vaccinium floribundum Kunth) is a wild berry that grows in high-altitude grasslands with nutritious and commercial potential in Ecuador. In this study, the use of PPM^TM (Plant Preservative Mixture™) was effective controlling contamination for the in vitro establishment of Vaccinium floribundum Kunth in contrast to a conventional method using EtOH and Clorox. Stems were defoliated and cut into 1 cm segments, then immersed in liquid MS (Murashige & Skoog) supplemented with 5% v/v PPM^TM without pH adjustment for 5 hours under constant shaking. After immersion, segments were transferred to flasks containing WPM (Woody Plant Media) medium supplemented with an additional 2 mlL^-1 PPM^TM. Persistent microbial contaminants in the in vitro explants were isolated and identified through molecular methods and gene sequences analyzed using the GenBank database resulted in the identification of three bacterial species: Methylobacterium sp., Methylobacterium radiotolerans, and Bacillus pumilus. In addition, three fungal species were also discovered: Xylaria sp., Xylaria feejeensis, and Diaporthe lutecens. Additionally, a multiplication assay was made with the aseptic stems from the sterilization protocol to evaluate four different growth regulators: 2ip, kinetin, zeatin and meta-topolin. kinetin showed very low responses with a mean of 1.2 shoots per stem. The highest number of shoots per stem (9 shoots) was obtained with 5 mg L^-1 2ip. The use of zeatin and meta-topolin facilitated shoot proliferation with the following concentrations: 3 mg L^-1zeatin + 0.5 mg L^-1 NAA (1-Naphthaleneacetic Acid) and 3 mg L^-1Meta-topolin + 0.5 mg L^-1NAA. These findings demonstrate the successful establishment of an in vitro disinfection and multiplication protocol for V. floribundum.

Cepas de Akanthomyces uredinophilum, Simplicillium lanosoniveum y Trichoderma spp. presentan alta actividad endófita e inducen un mejor crecimiento de plantas de café

2025-05-25T13:34:40+00:00

El cultivo de café (Coffea arabica L.) es afectado por la roya (Hemileia vastatrix) que causa pérdidas de más del 70% en la producción, el uso de hongos endófitos es una estrategia biológica para el control de enfermedades. El objetivo de este trabajo fue evaluar la actividad endófita de 14 cepas de hongos y su efecto en el crecimiento de plantas de café var. Caturra. Se inocularon semillas de café con una concentración de 1×10⁶ conidios mL^-1 de agua, se sembraron y organizaron en diseño experimental completamente al azar, tres repeticiones de ocho plantas por cepa. A los 30, 60 y 120 días después de la emergencia de plántulas, se tomaron muestras de cinco segmentos de hoja por planta, de 5 mm de diámetro y se evaluó la actividad endófita, se registró inicio de crecimiento del hongo (días), crecimiento inicial del hongo (%) y crecimiento total del hongo (%). Para evaluar el efecto de las cepas de hongo en el crecimiento de las plantas de café se evaluaron altura de planta, diámetro de tallo, número de hojas, pares de hojas, número de ramas e índice de contenido de clorofila. Se realizó análisis de varianza y prueba de separación de medias Tukey (p ≤ 0,05). Tres cepas de A. uredinophilum (CHE-CNRCB 435, 616 y 988), dos de S. lanosoniveum (CHE-CNRCB 438 y 544) y tres de Trichoderma (CHE-CNRCB 398, 1057 y 1062) presentaron actividad endófita mayor al 70%; las tres cepas de Trichoderma spp., indujeron mejor crecimiento de plantas de café.

Resilience of progeny of Swietenia macrophylla to the simulated attack of Hypsipyla grandella in nursery

2025-05-25T15:25:54+00:00

The resilience of seedlings from four open-pollinated families of Swietenia macrophylla to simulated attacks by Hypsipyla grandella was evaluated at the nursery stage to determine the possibility of early selection of individuals from the most resilient families and establish sustainable forest plantations in the Peruvian Amazon. Significant differences were detected among families for diameter (D), sprout length (SL), and basal sprout area (BA). The coefficient of determination for genotypic effects was moderate (range: 0.248 – 0.457) for H (plant height), D, SL, and BA, and low (< 0.15) for plant base height (HB), number of sprouts (NR), number of branches (NB), and number of leaves (NL). The genetic correlation for the traits H, D, SL, BA, NR, NB, and NL ranged from 0.228 to 0.996, indicating that an increase in one of these traits can result in an increase in the other. This is important because there is the possibility of early selection of families for the traits D, SL, and BA for the development of plantations with families resistant to attack. Therefore, the genetic and phenotypic variation observed in the families suggests the possibility of early selection as a promising strategy for genetic improvement programs, using a larger number of families than those used in the present study, since theoretically larger samples may contain greater genetic variation between and within families.

Antixenosis of different maize genotypes in storage affects feeding preferences and oviposition of Sitophilus zeamais Moth

2025-06-03T19:23:36+00:00

During corn storage, significant losses occur due to pest attacks, especially the weevil, Sitophilus zeamais Motschulsky. This study aimed to evaluate the feeding preference of Sitophilus zeamais on seeds of stored corn genotypes. The tests were carried out in the laboratory of the Center for Scientific and Technological Development in Pest and Disease Management (NUDEMAFI) at the Center for Agricultural Sciences and Engineering of the Federal University of Espírito Santo (UFES) in Alegre, in an air-conditioned room with a maximum temperature of 26.4 and a minimum of 26.2 ºC (± 2 ºC) and humidity between 70% and 75%. A host preference test with free choice was performed on insects from Nudemafi breeding, aged 5 to 10 days, in six (6) arenas with six (6) replicates using a completely randomized design (CRD). After 96 hours, the following were evaluated for each genotype: number of insects attracted, insect weight, number of infested seeds, percentage of seed loss, and 60 days after infestation, the percentage of emerged insects, physical and bromatological composition were determined. The results showed significant differences in the preference of Sitophilus zeamais adults in relation to the maize genotypes analyzed; the lowest food preference was observed in the Purple genotype (4.1%), followed by AG1051, which obtained 8.3% respectively. The genotypes presented antixenosis due to the effect of the nutritional properties and physical hardness of the seed.

Protocolo para germinação e micropropagação in vitro de Himatanthus Sucuuba (Spruce ex Müll. arg.) Woodson

2024-12-19T19:27:23+00:00

Himatanthus sucuuba possui importância na medicina popular e é amplamente utilizada como antitumoral, antifúngica, vermífuga e anti-anêmica. Nesse contexto, objetivo deste trabalho foi desenvolver protocolo de germinação e micropropagação in vitro de H. sucuuba. As sementes foram imersas em solução de Cabrio Top 1,0% (v/v) por uma hora em agitador magnético e depois em solução de NaOCl diluída a 0,1% (v/v) durante 30 minutos sob agitação, seguido de imersão em álcool 70% por 1 minuto, posteriormente as sementes foram enxaguadas quatro vezes com água destilada estéril, depois foram inoculadas em meio MS suplementados com as auxinas AIA, ANA e AIB, nas concentrações de 0,0; 1,0; 3,0; 5,0 mg L^-1. O delineamento experimental foi inteiramente casualizado, utilizando 10 tratamentos com 3 repetições de 10 sementes (n=30). Foi observado que o meio MS suplementado com AIA (5,0 mg L^-1) resultou em 80% de germinação e plântulas com 5,97 cm de altura e 4,2 segmentos nodais. Para estimular o enraizamento, os segmentos nodais foram cortados e inoculados em meio MS acrescido de BAP (0,1 mg L^-1) e em interação com as auxinas AIA, 2,4-D e ANA, nas concentrações de 0,0; 3,0; 5,0 e 8,0 mg L^-1 e, mantidos em sala de crescimento a 25 ± 2 °C, com fotoperíodo de 16 h. A combinação BAP+AIA (0,1 + 8,0 mg L^-1) apresentou os melhores resultados com 30% de enraizamento, 100% de brotações e 40% de formação de calos. Em conclusão, a propagação in vitro é uma técnica promissora para produção de mudas in vitro de H. succuba.