The present work focused on the screening process of different inorganic oxides and different temperatures for the epoxidation reaction of macaw palm vegetable oil without using solvent, a promising Brazilian biomass that can substitute other vegetable oils (e.g., soybean oil) in technological applications. This oil has an iodine value of 108.48 g of I2 per 100 g being categorized as a semi-dry oil. The epoxidized vegetable oil can be applied in manifold areas in polymer science. The epoxidation reaction here presented avoided organic solvents and organic acids and aimed to produce a greener route using metal oxides or niobium phosphate as a peroxide-activating catalyst. The experimental parameters were maintained as 10 mol% of catalyst loading and a time of 24 h; however, the temperature for some catalysts was changed to improve the epoxide conversion. Experiments were measured by proton nuclear magnetic resonance (1H NMR). Experiments using titanium oxide (TiO2) as a catalyst reached a conversion greater than 84.7%, while experiments using aluminium oxide (Al2O3) or lanthanum oxide (La2O3) achieved conversions of 22.6 and 30.1%, respectively. Furthermore, it was observed that both niobium compounds instantly react with hydrogen peroxide to form peroxy derivatives. solvent e.g., eg e (e.g. applications 10848 108 48 108.4 I semidry semi dry science peroxideactivating activating 1 mol 2 h however 1H H NMR. NMR . NMR) TiO2 TiO (TiO2 847 84 7 84.7% Al2O3 AlO Al O (Al2O3 La2O3 LaO La (La2O3 226 22 6 22. 301 30 30.1% respectively Furthermore derivatives e.g. (e.g 1084 4 108. (TiO 8 84.7 Al2O (Al2O La2O (La2O 3 30.1 e.g 84. 30.

The species Oryza sativa (rice) and Musa cavendishii (banana) are sources of cellulose-rich waste biomass in the Amazon region, Tocantins State. This research investigates the nanoscale production of cellulose through the interactions between three choline amino acid ionic liquids Ch[AA]IL and the respective fibers by pretreatment. To this end, the synthesis of three ILs was carried out: choline arginate Ch[Arg], choline glycinate Ch[Gly] and choline lysinate Ch[Lys], characterized by Fourier transform infrared spectroscopy (FTIR). The samples resulting from the pretreatment were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). It was possible to infer from the SEM micrographs that Ch[Arg] caused greater fiber breakage than the other ILs. The TEM analyses identified fibers up to 16 nm in diameter. Positive effects were observed in the diffractograms, although no crystallinity was obtained in the pretreated samples. Thermogravimetry curves showed that the fibers treated with Ch[Arg] showed higher thermal stability. rice (rice banana (banana celluloserich rich region State ChAAIL Ch AA IL end out ChArg, ChArg Arg , ChGly Gly Ch[Gly ChLys, ChLys Lys Ch[Lys] FTIR. FTIR . (FTIR) SEM, (SEM) TEM, (TEM) Xray X ray XRD (XRD TGA. TGA (TGA) Ch[Arg 1 diameter diffractograms stability Ch[Lys (FTIR (SEM (TEM (TGA

In the Amazon, Euterpe oleracea Mart. (açaí), is part of the identity of traditional communities, and the fruit is integrated into their everyday sociocultural dynamics. Hydrolysis and pyrolysis of residual biomass can be alternatives to yield sugars, ethanol, biochar and bio-oil. The açaí seeds subjected to oxidative pretreatment followed by acid hydrolysis increased cellulose to fermentable sugars (reaching 23.5%) and second-generation ethanol production (17.441 L t−1). Açaí oil (ca. 30%) was extracted using a Soxhlet apparatus (using hexane as solvent) and detected through gas chromatography coupled to mass spectrometry (GC-MS), where acids accounted for 82.43% of the total composition, while alcohols comprised only 13.15%. For pyrolysis, temperatures (500 and 550 °C), time (20 and 30 min), and activation temperature (750 and 800 °C) were evaluated, resulting in yields of ca. 22% for biochar and 30% for bio-oil. For the bio-oil, the main compounds detected by GC-MS were acids (16.3%), aldehydes (13.08%), amides (12.19%), alcohols (6.72%), and phenols (4.64%). The obtained biochar displayed surface area values of 553.7 m2 g−1 and 10% crystallinity, indicating its more amorphous nature. Amazon Mart açaí, , (açaí) communities dynamics biooil. biooil bio oil. bio-oil reaching 23.5% 235 23 5 secondgeneration second generation 17.441 17441 17 441 (17.44 t−1. t1 t t−1 . 1 t−1) ca (ca solvent GCMS, GCMS GC MS (GC-MS) 8243 82 43 82.43 composition 1315 13 15 13.15% 500 (50 55 °C, C °C 20 (2 3 min, min min) 750 (75 80 evaluated 22 biooil, oil, 16.3%, 163 16.3% 16 (16.3%) 13.08%, 1308 13.08% 08 (13.08%) 12.19%, 1219 12.19% 12 19 (12.19%) 6.72%, 672 6.72% 6 72 (6.72%) 4.64%. 464 4.64% 4 64 (4.64%) 5537 553 7 553. m g1 g g− 10 crystallinity nature (açaí 23.5 2 17.44 1744 44 (17.4 t− (GC-MS 824 8 82.4 131 13.15 50 (5 ( 75 (7 16.3 (16.3% 130 13.08 0 (13.08% 121 12.19 (12.19% 67 6.72 (6.72% 46 4.64 (4.64% 23. 17.4 174 (17. 82. 13.1 16. (16.3 13.0 (13.08 12.1 (12.19 6.7 (6.72 4.6 (4.64 17. (17 13. (16. (13.0 12. (12.1 6. (6.7 4. (4.6 (1 (16 (13. (12. (6. (4. (13 (12 (6 (4

ABSTRACT Exposing seeds to agents that elicit tolerance to abiotic stress, such as phytohormones and organic acids, during hydration and dehydration cycles can determine their response to later stimuli, e.g. exposure to salt stress. The aim of this study was to evaluate the action of priming cycles with different eliciting agents of salt stress tolerance on seeds of the cowpea varieties Sempre Verde and Pingo de Ouro. The seeds were subjected to the following treatments: 0.0 mM NaCl (control); 100 mM NaCl (salt stress); salt stress + three seed-priming cycles (PC) in water; salt stress + PC in gibberellic acid; salt stress + PC in hydrogen peroxide; salt stress + PC in salicylic acid; salt stress + PC in ascorbic acid. The following variables were analysed: germination, growth, dry weight, salt tolerance index, total soluble sugars, total free amino acids and proline. Salt stress (100 mM NaCl) reduced germination, length and biomass accumulation in the Sempre Verde and Pingo de Ouro varieties. These showed the best response to the priming cycles with gibberellic and salicylic acids, which promoted greater germination potential, length and biomass under a salt stress of 100 mM NaCl, affording greater tolerance via osmotic regulation, especially in the Sempre Verde variety. stimuli eg e g e.g treatments 00 0 0. control (control) 10 stress) seedpriming seed (PC water acid peroxide analysed growth weight index sugars proline (10 potential regulation variety (control 1 (1 (

ABSTRACT Proper waste management is a major worldwide concern; waste is disposed of directly into the environment, affecting water, soil and air quality. The development and production of green energy sources is strongly encouraged in modern society. The aim of this study, in accordance with Sustainable Development Goals (SDGs) 1, 2 and 7 of the 2030 Agenda of the UN, is to combine the correct disposal of animal waste with the generation of energy to mitigate the energy insecurity of families in an extremely vulnerable semi-arid region in the north-east of the country using biodigesters. To this end, a conceptual proposal was drawn up for a low-cost, easy-to-maintain and easy-to-use biodigester. A small-scale prototype was used to assess its operation by evaluating the main factors that affect biogas production (pH, temperature and the biomass properties: total solids, fixed solids, volatile solids, concentration of volatile fatty acids and C/N ratio). Evaluation of the test prototype gave satisfactory results that corroborate other studies and make it possible to propose an economically viable and efficient full-scale biodigester for biogas production. concern environment water quality society study SDGs (SDGs 1 203 UN semiarid semi arid northeast north east biodigesters end lowcost, lowcost low cost, cost low-cost easytomaintain easy maintain easytouse use smallscale small scale pH, pH (pH properties solids CN C N ratio. ratio . ratio) fullscale full 20

Seeking a viable alternative to fossil fuels as the primary energy source, bioethanol has emerged as a promising second-generation fuel derived from lignocellulosic biomass. With Brazil ranking pineapple as the third most produced fruit in temporary crops, this study aims to assess the impact of chemical pretreatment techniques, specifically organosolv and diluted acid, on the residual biomass of Pérola pineapple peel to enhance bioethanol production. Employing an experimental design that incorporates temperature, reaction time, and varying concentrations of organic solvent, the study examines their effects on the susceptibility of the substrate to saccharification for future bioethanol generation. Factors such as alphacellulose, hemicellulose, and lignin were evaluated in triplicate and subjected to statistical analysis using the Tukey test with a confidence level of 95%. Upon application of the pretreatment methods, it was observed that the organosolv solvent approach (utilizing water and ethanol) with sulfuric acid exhibited superior sugar conversion, yielding the highest concentration of xylose at 9.13 g L-1. Additionally, the pretreated biomass contained 1.38 g L 1 of cellobiose, 3.11 g L-1 of arabinose, and 3.76 g L-1 of glucose. This technique demonstrates promising potential for obtaining fermentable sugars crucial for bioethanol production. source secondgeneration second generation crops techniques production temperature time alphacellulose hemicellulose 95 95% methods utilizing ethanol conversion 913 9 13 9.1 L1. L1 1. Additionally 138 38 1.3 cellobiose 311 3 11 3.1 L- arabinose 376 76 3.7 glucose 91 9. 31 3. 37 7

RESUMO Santa Catarina é um importante produtor de banana, responsável por 722 toneladas anuais. Para cada 1.000 kg de banana colhida, são gerados aproximadamente 3.000 kg de pseudocaule, 650 kg de cascas e 350 kg de frutos rejeitados. Estudos avaliaram a utilização de resíduos de banana para produção de bioetanol. Resíduos sólidos como bagaço de pseudocaule de banana, cascas de banana e vinhaça (resíduo de caldo fermentado) são produzidos nesse processo. Este estudo teve como objetivo quantificar e caracterizar esses resíduos para produção de biogás e metano. Cascas de banana e vinhaça foram melhores por conterem menor teor de sólidos totais e relações C:N (carbono:nitrogênio) favoráveis (10 - 30:1), proporcionando maior potencial bioquímico de metano (260 mLCH4 gvs -1) em comparação ao pseudocaule de bananeira bagaço (201 mLCH4 gvs -1). No entanto, a vinhaça apresentou alto teor de sulfeto de hidrogênio (0,0783%), necessitando de dessulfurização do biogás gerado para seu uso seguro. No geral, os resultados indicam que o bagaço do pseudocaule da banana, as cascas de banana e a vinhaça têm potencial substancial para a produção de biogás e metano devido às suas altas taxas de degradação. A composição do biogás atende aos critérios de utilização, com concentrações adequadas de metano e dióxido de carbono, destacando a viabilidade desses resíduos para geração de energia e contribuindo para a sustentabilidade no cultivo da banana. 72 anuais 1000 1 000 1.00 colhida 3000 3 3.00 65 35 rejeitados bioetanol resíduo fermentado processo CN C N carbononitrogênio carbono nitrogênio (carbono:nitrogênio 10 (1 301, 301 30 , 30:1) 260 (26 mLCH -1 201 (20 1. . entanto 0,0783%, 00783 0,0783% 0 0783 (0,0783%) seguro geral degradação 7 100 00 1.0 300 3.0 6 ( 30:1 26 (2 20 0078 0,0783 078 (0,0783% 3. 30: 2 007 0,078 07 (0,0783 0,07 (0,078 0,0 (0,07 0, (0,0 (0, (0

ABSTRACT Santa Catarina is a significant banana producer, responsible for 722 tons annually. For every 1,000 kg of bananas harvested, approximately 3,000 kg of pseudostem, 650 kg of peels, and 350 kg of rejected fruit are generated. Studies have evaluated the use of banana residues for bioethanol production. Solid residues like banana pseudostem bagasse, banana peels, and vinasse (fermented broth residue) are produced during this process. This study aimed to quantify and characterize these residues for biogas and methane production. Banana peels and vinasse were more suitable for containing lower total solids content and favorable C:N (carbon:nitrogen) ratios (10-30:1), yielding higher biochemical potential of methane (260 mLCH4 gvs -1) compared to banana pseudostem bagasse (201 mLCH4 gvs -1). However, vinasse had a high hydrogen sulfide content (0.0783%), necessitating desulphurization for safe biogas use. The results indicate that banana pseudostem bagasse, banana peels, and vinasse have substantial potential for biogas and methane production due to their high degradation rates. The biogas composition meets the criteria for use, with adequate methane and carbon dioxide concentrations, highlighting the viability of these residues for energy generation and contributing to sustainability in banana cultivation. producer 72 annually 1000 1 000 1,00 harvested 3000 3 3,00 65 35 generated fermented residue process CN C N carbonnitrogen nitrogen (carbon:nitrogen 10301, 10301 10 30 , (10-30:1) 260 (26 mLCH -1 201 (20 1. . However 0.0783%, 00783 0.0783% 0 0783 (0.0783%) rates concentrations cultivation 7 100 00 1,0 300 3,0 6 1030 (10-30:1 26 (2 - 20 0078 0.0783 078 (0.0783% 1, 3, 103 (10-30: 2 ( 007 0.078 07 (0.0783 (10-30 0.07 (0.078 (10-3 0.0 (0.07 (10- 0. (0.0 (10 (0. (1 (0

RESUMO No clima semiárido, o crescimento de mudas frutíferas é desafiado pelo estresse hídrico característico da região, o que pode restringir seu desenvolvimento e, consequentemente, afetar a produção. Nesse contexto, o objetivo foi avaliar o efeito do extrato pirolenhoso nas características de troca gasosa, pigmentos fotossintéticos, crescimento e biomassa de pitangueira sob diferentes intensidades de déficit hídrico. O experimento foi conduzido em casa de vegetação utilizando um delineamento em blocos casualizados em um esquema fatorial 3 × 2, com quatro repetições, correspondendo a períodos de déficit hídrico foram de 7 e 14 dias, além do controle (irrigação diária), no substrato sem e com extrato pirolenhoso. As plantas foram avaliadas quanto às características de trocas gasosas foliares, índices de clorofila, crescimento e biomassa seca. A aplicação de extrato pirolenhoso aos 7 dias de déficit hídrico elevou a taxa fotossintética, a eficiência de carboxilação e o índice de qualidade de Dickson das mudas de pitanga em 40,04, 42,85 e 41,51%, respectivamente, em comparação aos 14 dias de déficit hídrico. O extrato pirolenhoso foi efetivo como um atenuante do estresse hídrico nas mudas de pitanga, especialmente durante os primeiros sete dias de exposição ao estresse. Assim, sua aplicação é recomendada como uma medida preventiva e de curto prazo para mitigar tais efeitos nas mudas de pitanga. semiárido região consequentemente produção contexto gasosa fotossintéticos 2 repetições 1 irrigação diária, diária , diária) foliares clorofila seca fotossintética 4004 40 04 40,04 4285 42 85 42,8 4151 41 51 41,51% respectivamente Assim 400 4 0 40,0 428 8 42, 415 5 41,51 40, 41,5 41,

ABSTRACT In the semi-arid climate, the growth of fruit seedlings is challenged by the water stress characteristic of the region, which can restrict their development and, consequently, affect production. In this context, the aim was to assess the effect of pyroligneous extract on gas exchange characteristics, photosynthetic pigments, growth, and biomass of pitanga under different intensities of water deficit. The experiment was conducted using a randomized block design in a 3 × 2 factorial scheme, with four replicates, corresponding to water deficit periods (7 and 14 days) and control (daily irrigation), in substrates with and without pyroligneous extract. The plants were evaluated for gas exchange characteristics, chlorophyll indices, growth, and dry biomass. Application of pyroligneous extract after 7 days of water deficit increased the photosynthetic rate, carboxylation efficiency and Dickson quality index of pitanga seedlings by 40.04, 42.85 and 41.51%, respectively, compared to 14 days of water deficit. Pyroligneous extract was effective as a water stress attenuator in pitanga seedlings, especially during the first seven days of exposure to stress. Therefore, its application is recommended as a preventive and short-term measure to mitigate such effects on pitanga seedlings. semiarid semi arid climate region consequently production context characteristics pigments scheme replicates ( 1 daily irrigation, irrigation , irrigation) indices rate 4004 40 04 40.04 4285 42 85 42.8 4151 41 51 41.51% respectively Therefore shortterm short term 400 4 0 40.0 428 8 42. 415 5 41.51 40. 41.5 41.

Abstract Introduction. Sweet potato (Ipomoea batatas (L) Lam.) is sensitive to weed competition, and chemical control in Costa Rica is challenging due to limited local information on herbicide selectivity. Objective. To determine the selectivity of six herbicides applied at different stages of development to Criollo sweet potatoes and their effect on coverage, biomass, and crop yield. Materials and methods. Between August and December 2021, three experiments were conducted at the Fabio Baudrit Moreno Agricultural Experimental Station, Universidad de Costa Rica, Alajuela, Costa Rica. Herbicides were applied (in kg a.i. ha-1) as follows: a) Experiment 1: 0.36 of metribuzin, 1.50 of pendimethalin, 0.48 of clomazone, 0.075 of halosulfuron, 1.00 of linuron, and 1.25 of metolachlor, applied six days after planting (dap) in a randomized block design with four repetitions; b) Experiment 2: 1.00 of linuron and 0.36 of metribuzin 0.36, applied at -1, 15 and 30 dap, in a randomized block design with a 2x3 factorial arrangement and three repetitions; and c) Experiment 3: 0.075 of halosulfuron and 0.36 of metribuzin, mixed with 0.125 of fluazifop-p-butyl in a randomized block design with three repetitions. Weeding was performed at 15 and 30 dap in all cases. Results. Root yield was not affected in any of the three experiments. Experiment 1: Only halosulfuron caused mild damage to the plants; no herbicide affected above-ground biomass production. Experiment 2: Only linuron and metribuzin applied at 15 and 30 dap caused mild damage. Experiment 3: The mixtures caused temporary damage to the plants. Conclusions. The evaluated herbicides were selective to the Criollo sweet potatoes, and did not affect the yield of marketable storage roots. Only halosulfuron caused mild damage in all application forms, and metribuzin and linuron only in late applications.

Resumen Introducción. El camote (Ipomoea batatas (L) Lam) es sensible a la competencia por arvenses, cuyo control químico en Costa Rica se dificulta por la limitada información local generada sobre selectividad de herbicidas. Objetivo. Determinar la selectividad de seis herbicidas aplicados en diferentes etapas de desarrollo al camote Criollo y su efecto en la cobertura, biomasa y rendimiento del cultivo. Materiales y métodos. Entre agosto y diciembre 2021, se realizaron tres experimentos en la Estación Experimental Agrícola Fabio Baudrit Moreno, Universidad de Costa Rica, Alajuela, Costa Rica. Estos incluyeron la aplicación de herbicidas (en kg i.a. ha-1) de la siguiente manera: a) experimento 1: 0,36 de metribuzin, 1,50 de pendimetalina, 0,48 de clomazone, 0,075 de halosulfuron, 1,00 de linuron y 1,25 de metolaclor, aplicados seis días después de la siembra (dds) en diseño de bloques al azar con cuatro repeticiones; b) experimento 2: 1,00 de linuron y 0,36 de metribuzin, aplicados a los -1, 15 y 30 dds, en diseño de bloques al azar con arreglo factorial 2x3 y tres repeticiones; y c) experimento 3: 0,075 de halosulfuron y 0,36 de metribuzin, mezclado con 0,125 de fluazifop-p-butil en diseño de bloques al azar con tres repeticiones. En todos los casos se realizó deshierba 15 y 30 dds. Resultados. En ninguno de los tres experimentos se vio afectada la producción de raíces reservantes. Experimento 1: solo el halosulfuron causó daños leves en las plantas; ningún herbicida afectó la producción de biomasa aérea. Experimento 2: solo el linuron y metribuzin aplicados 15 y 30 dds causaron daños leves. Experimento 3: las mezclas causaron daños temporales en las plantas. Conclusiones. Los herbicidas evaluados fueron selectivos al camote variedad Criollo y no afectaron el rendimiento de raíces reservantes comercializables; solo halosulfuron causó daños leves en todas las formas de aplicación, y metribuzin y linuron solo en aplicaciones tardías.

Abstract Introduction. The cultivation of dragon fruit (Hylocereus costaricensis and H. monocanthus) is increasing in Costa Rica, but technical information for its management, such as nutritional requirements, fertilization timing, and growth behavior, is lacking. Objective. To quantify and model the growth and nutrient uptake of dragon fruit (H. costaricensis and H. monocanthus) under dry tropics conditions in Costa Rica. Materials and methods. The research was conducted from 2017 to 2020 in Guanacaste, Costa Rica. Plants were sampled at 76, 165, 308, 450, 607, 903, 1249, and 1706 days after planting (DAP) and 205 fruits were analyzed. Dry matter was quantified, and the uptake of N, P, Ca, Mg, K, S, Fe, Cu, Zn, Mn, and B was calculated. Two logistic models were fitted to determine nutrient uptake, and linear regressions were calibrated for fresh fruit. Results. For a planting density of 3000 plants/ha, the nutritional requirements per hectare were: 137 kg N, 32 kg P, 327 kg K, 63 kg Mg, 32 kg S, 1,60 kg Zn, and 0,21 kg B. The best-fitting logistic model (RMSE = 0.09) accurately estimated the uptake of N, P, Ca, S, Zn, and B. The linear regression model demonstrated high predictive capacity (R2 > 0.85) for the nutrient requirements of N, P, K, Mg, and S in the fruit. Conclusion. Logistic models provided high precision in deterministically modeling nutrient uptake in dragon fruit plants. The study affectively quantified and modeled the nutritional behavior of the plants under Costa Rica’s dry tropical conditions, providing essential information for optimizing fertilization programs for the crop.

Resumen Introducción. El cultivo de pitahaya (Hylocereus costaricensis y H. monocanthus) está en aumento en Costa Rica, pero carece de información técnica para su manejo, como necesidades nutricionales, momentos de fertilización y comportamiento del crecimiento. Objetivo. Cuantificar y modelar el crecimiento y la absorción de nutrimentos del cultivo de pitahaya (H. costaricensis y H. monocanthus) en condiciones del trópico estacional seco de Costa Rica. Materiales y métodos. La investigación se realizó durante los años 2017-2020, en Guanacaste, Costa Rica. Se muestrearon plantas a los 76, 165, 308, 450, 607, 903, 1249 y 1706 días después de siembra (DDS) y 205 frutas. Se cuantificó la materia seca y se calculó la absorción de N, P, Ca, Mg, K, S, Fe, Cu, Zn, Mn y B. Se ajustaron dos modelos logísticos para determinar la absorción de nutrientes y se calibraron regresiones lineales en fruta fresca. Resultados. Para una densidad de siembra de 3000 planta/ha los requerimientos nutricionales del cultivo por hectárea fueron: 137 kg N, 32 kg P, 327 kg K, 63 kg Mg, 32 kg S, 1,60 kg Zn y 0,21 kg B. El modelo logístico de mejor ajuste (RMSE = 0,09) estimó de forma precisa la absorción de N, P, Ca, S, Zn y B. El modelo de regresión lineal tuvo alta capacidad predictora (R2 > 0,85) para los requerimientos de N, P, K, Mg y S en fruta. Conclusión. Los modelos logísticos tuvieron alta precisión para modelar de manera determinística la absorción de nutrientes en plantas de pitahaya. Además, se logró cuantificar y modelar de forma eficiente el comportamiento nutricional de las plantas en condiciones de trópico estacional seco de Costa Rica, lo que proporciona información esencial para los programas de fertilización del cultivo.

Abstract Introduction. Corn is one of the oldest known food grains. With climate change and frequent and severe droughts, the water available in the soil will be considerably reduced. Water deficit affects maize crop development to varying degrees, and sensitivity to this stress varies at different development stages. Objective. To identify the phenological stages most sensitive to water deficit in maize. Materials and methods. The experiment was conducted during two growing seasons in 2020 and 2021 in El Ejido, Los Santos province, Panama, under semi-controlled conditions in the greenhouse facilities of the Instituto Coronel Segundo de Villarreal. The commercial corn hybrid ADV-9293 was used and agronomic management was carried out according to the recommendations of the Institute for Agricultural Innovation of Panamá (IDIAP). Plant height, leaf length and width, stem diameter, biomass and yield components, such as number of rows per ear, number of grains per row and 100-grain mass, were determined throughout the crop cycle. Soil moisture was also determined by the gravimetric method. Water deficit at different stages was generated by drought simulation. Results. The grain yields of the control were higher than the different treatments evaluated with 12.83 t ha-1, followed by the treatment with grain filling stress with 10.31 t ha-1. Two periods were determined to be more sensitive to water deficit; these were the stages from 20 to 35 and 40 to 55 days after planting. Water deficit in the different phenological stages of the crop had a negative impact on the relative chlorophyll content. Conclusion. The pre-flowering and flowering stages were more sensitive to water deficiency in maize.

Resumen Introducción. El maíz es uno de los granos alimenticios más antiguos conocido. Con el cambio climático y las sequías severas y frecuentes, se reducirá en gran medida el agua disponible en el suelo. El déficit hídrico afecta en diversos grados el desarrollo del cultivo de maíz y la sensibilidad a este estrés varía en las diferentes etapas de desarrollo. Objetivo. Identificar las etapas fenológicas más sensibles al déficit hídrico en el cultivo de maíz. Materiales y métodos. El experimento se realizó durante dos ciclos en los años 2020 y 2021 en El Ejido, Provincia de Los Santos, Panamá. Se desarrolló bajo condiciones semicontroladas en la casa de cultivo del Instituto Coronel Segundo de Villarreal. Se utilizó el híbrido de maíz comercial ADV-9293. El manejo agronómico se realizó según las recomendaciones del Instituto de Innovación Agropecuaria de Panamá (IDIAP). Durante todo el ciclo del cultivo, se determinaron las variables altura de planta, largo y ancho de hojas, diámetro del tallo, biomasa y los componentes del rendimiento como número de hileras por mazorca, número de granos por hilera y peso de cien granos. También, se determinó la humedad del suelo por el método gravimétrico. El déficit hídrico en distintas etapas se generó a través de la simulación de sequía. Resultados. El rendimiento de grano del testigo superó los diferentes tratamientos evaluados con 12,83 t ha-1, seguido por el tratamiento con estrés en el llenado de grano con 10,31 t ha-1. Se determinaron dos períodos más sensibles al déficit hídrico; los cuales son las etapas comprendidas desde los 20 a 35 y 40 a 55 dds. El déficit hídrico, durante las diferentes etapas fenológicas del cultivo, tuvo un impacto negativo en el contenido relativo de clorofilas. Conclusión. Las etapas de prefloración y floración resultaron más sensibles a la deficiencia hídrica en el cultivo del maíz.

ABSTRACT Due to the reduction of Chondracanthus chamissoi natural beds in Peru, different alternatives have been proposed for its cultivation, generally opting for suspended (CS) and bottom (CF) cultivation systems. When thalli reach commercial size, they get harvested for sale, and it is unknown if their specific growth rate (TCE) and/or regenerative capacity decrease. Therefore, the present work aimed to determine the TCE in the post-harvest regenerative capacity and the life cycle phase dominance of C. chamissoi in two pruning events comparing CS and CF during august 2019 and february 2020 in the south-central coast of Peru. The TCE was higher in CS (1.67 % day-1) in comparison to CF (1.47 % day-1). Likewise, CS showed better results in biomass (631.6 ± 81.3 gm-1) and length (23.91 ± 5.8 cm) compared to CF (256.5 ± 33.6 gm-1 and 21.10 ± 7.50 cm) during the first harvest. After the second harvest, lower values in biomass (CS: 160.2 ± 180 gm-1, CF: 59.4 ± 110 gm-1) and length (CS: 16.23 ± 3.68 cm, CF: 15.73 ± 4.25 cm) were observed. The dominant phase was the vegetative one, followed by the carposporic and tetrasporic phases. In conclusion, suspended cultivation showed better results; it is recommended to leave an average of 4-5 cm during pruning, to allow a better growth for a new harvest in less than 3 months.

RESUMEN Ante la reducción de praderas naturales de Chondracanthus chamissoi en Perú se han planteado diferentes alternativas para su cultivo, principalmente optando por sistemas de cultivo suspendido (CS) y cultivo de fondo (CF). Al alcanzar la talla comercial, los talos sufren podas para su comercialización, desconociéndose si disminuyen su tasa de crecimiento especifica (TCE) y/o capacidad regenerativa. Por ello, el presente trabajo tuvo como objetivo determinar la TCE en la capacidad regenerativa post-cosecha y la dominancia de fases del ciclo de vida de C. chamissoi en dos eventos de poda comparando CS y CF entre agosto de 2019 y febrero de 2020 en la costa centro-sur del Perú. La TCE fue mayor en CS (1.67 % día-1) respecto de CF (1.47 % día-1). Asimismo, CS mostró mejores resultados en biomasa (631.6 ± 81.3 gm-1) y longitud (23.91 ± 5.8 cm) en comparación a CF (256.5 ± 33.6 gm-1 y 21.10 ± 7.50 cm) tras la primera poda. Luego de la segunda poda, se observaron valores reducidos en biomasa (CS: 160.2 ± 180 gm-1, CF: 59.4 ± 110 gm-1) y longitud (CS: 16.23 ± 3.68 cm, CF: 15.73 ± 4.25 cm). Se determino a la fase vegetativa como dominante, seguida de talos carpospóricos y finalmente los tetraspóricos. Se concluye que CS muestra mejores TCE luego de eventos poda y se recomienda dejar en promedio 4-5 cm de talo para facilitar una rápida regeneración.

ABSTRACT This article describes the actors involved in the recommendation of the Peruvian anchoveta catch quota prior to the fishing seasons of each region (north-central and south), as well as the bias associated with it. The data on biomasses, quotas, and landings correspond to the 2000-2022 period, while the recommendations for the total quota correspond to 2019-2022. For the north-central region, Imarpe recommends Produce an exploitation rate lower than or equal to 0.35. This is done through a decision table for four probable oceanographic environment scenarios, considering a remaining biomass to ensure sustainability. The compliance of Peruvian anchoveta catches quotas in the first fishing seasons has been higher than 90 %, while in the second fishing seasons, catches have even been less than 50 %, as in the case of: 2001, 2019, 2010 and 2017. Between 2019 and 2022, Produce opted for the following: i) with a quota lower than that recommended in the decision table (I-2021, II-2020, I-2019) and ii) with a quota higher than that recommended in the biomass of the decision table (I-2022, II-2021, II-2022, II-2019 and I-2020). The observation error is lower (0.10) for the summer surveys and higher (0.15) for the winter-spring (spawning biomass and hydroacoustic surveys).

RESUMEN Este artículo describe los actores que intervienen en la recomendación de la cuota de captura de anchoveta, previo a las temporadas de pesca para cada región (norte-centro y sur), así como el sesgo asociado a la misma. Los datos de las biomasas, cuotas y desembarques corresponden al período 2000-2022, mientras que las recomendaciones para la cuota total corresponden a 2019-2022. Para la región norte-centro, el Imarpe recomienda a Produce una tasa de explotación menor o igual a 0.35 mediante una tabla de decisión para cuatros escenarios probables de ambiente oceanográfico, considerando una biomasa remanente para asegurar su sostenibilidad. El cumplimiento de las cuotas de capturas de anchoveta en las primeras temporadas de pesca ha sido mayor a 90 %, mientras que en las segundas temporadas de pesca se han capturado inclusive menores a 50 %, como es el caso del: 2001, 2019, 2010 y 2017. Entre 2019 y 2022, Produce optó lo siguiente: i) con cuota menor a la recomendada en la tabla de decisión (I-2021, II-2020, I-2019) y ii) con cuota mayor a la recomendada en la biomasa a la tabla de decisión (I-2022, II-2021, II-2022, II-2019 y I-2020). El error de observación es menor (0.10) en los cruceros de verano y mayor (0.15) en invierno-primavera (cruceros de biomasa desovante e hidroacústicos).

Summary: Currently, agricultural activity is constantly threatened by the effects of climate change and radical expression of environmental factors as irregular rainfall distribution responsible for water availability and deficit. These factors generate water stress in productive systems, whose negative effect is reflected on morphological, physiological and biochemical aspects of vegetative growth. The use of biostimulants arises as a strategy to counteract this impact, improving crop efficiency in the use of resources and generating responses, as metabolite production, among other substances that mitigate the effects of oxidative stress. In this context, waxes, hydrogen peroxide (H2O2), salicylic acid (SA) and ALGAENZIMSMR were used on raspberry plants subjected to moderate water stress (-0. 8 MPa) to evaluate the fruit response in aspects of vegetative growth, physiological and biochemical quality. For the establishment, a completely randomized design was used with 5 treatments: Green Cover as 5 mL L-1, H2O2 10-4 M, salicylic acid 0.27 mM, ALGAENZIMSMR 7.5 mL L-1 and the control with 50% recovery of the transpired volume as well as water potential similar to the rest of plants and 4 replicates. The results showed that waxes, SA and algal extract increased the photosynthetic rate; the four treatments increased root length; waxes increased root height; and H2O2 increased root biomass. Compared to the control, higher levels of vitamin C and anthocyanins were produced in fruits - a very important aspect due to the functionality of these compounds in human health. Therefore, the use of these biostimulants are a very useful tool for crop management in environments with water restriction.

Resumen: En la actualidad la actividad agrícola se ve amenazada constantemente por los efectos del cambio climático y la expresión radical de los factores ambientales, como la irregularidad en la distribución pluvial responsable de la disponibilidad del agua y déficit, que genera estrés hídrico en los sistemas productivos, cuyo efecto negativo se refleja en aspectos de crecimiento vegetativo, morfológicos, fisiológicos y bioquímicos. El uso de bioestimulantes surge como estrategia para contrarrestar este impacto, mejorando la eficiencia de los cultivos en el uso de los recursos y generar respuestas, como la producción de metabolitos entre otras sustancias, que mitigan los efectos del estrés oxidativo. Bajo este contexto se planteó el uso de ceras, peróxido de hidrogeno (H2O2), ácido salicílico (AS) y algaenzims, sobre plantas de frambuesa sometidas a estrés hídrico moderado (-0.8 MPa) con el objetivo de evaluar la respuesta en aspectos de crecimiento vegetativo, fisiológicos y calidad bioquímica de frutos, para el establecimiento se empleó un diseño completamente al azar con 5 tratamientos: greencover as® 5 mL L-1, H2O2 10-4 M, ácido salicílico 0.27 mM, algaenzims® 7.5 mL L-1 y el control con recuperación del 50% del volumen transpirado y con potencial hídrico similar al resto de plantas y 4 repeticiones. Como resultados se obtuvo que las ceras, AS y el extracto de algas incrementaron la tasa fotosintética, los cuatro tratamientos aumentaron la longitud de raíces, las ceras la altura, y el H2O2 la biomasa de raíz. Por otro lado, en comparación con el control, se produjeron mayores niveles de vitamina C y antocianinas en frutos, un aspecto muy importante por la funcionalidad de estos compuestos en la salud humana. Por lo tanto, el uso de estos bioestimulantes se puede visualizar como una herramienta de gran utilidad para el manejo de cultivos en ambientes con restricción de agua.

Summary: Soil solution (SS) constitutes the volume from which plant roots extract dissolved nutrients. Despite its importance, the impact of its composition due to the application of organic amendments has been relatively little studied. The objective of this research was to study the impact of humic acids (HA) and chitosan (Cs) on the concentration of minerals in the SS, as well as their effect on the yield of the cabbage crop (Brassica oleracea L.). Under greenhouse conditions with calcareous soil, two doses of HA were applied (200 and 500 kg ha-1), as well as 50 and 150 kg ha-1 of Cs in a targeted manner. From the SS, 22 samples were taken non-destructively from the root zone once a week. The results of mineral content in the soil solution and mineral content on the biomass did not present significant differences, however, it was noted that the Cs50 treatment stimulated 41% higher plant biomass than the control (P ≤ 0.5, Tukey). It is concluded that Cs and HA do not significantly impact the ionic content of the SS or the mineral content of the biomass, although they do stimulate the yield.

Resumen: La solución del suelo (SS) constituye el volumen de donde las raíces de las plantas extraen los nutrientes disueltos. A pesar de su importancia, el impacto de su composición por la aplicación de enmiendas orgánicas se encuentra relativamente poco estudiado. El objetivo de esta investigación fue estudiar el impacto de los ácidos húmicos (AH) y quitosán (Cs) sobre la concentración de los minerales en la SS, así como su efecto en el rendimiento del cultivo de col (Brassica oleracea L.). En condiciones de invernadero con suelo calcáreo se aplicaron dos dosis de AH (200 y 500 kg ha-1), así como 50 y 150 kg ha-1 de Cs de forma dirigida. De la SS se tomaron 22 muestras en forma no destructiva de la zona de la raíz una vez por semana. Los resultados del contenido mineral en la solución del suelo y del contenido mineral en la biomasa no presentaron diferencias significativas, no obstante, se apreció que el tratamiento Cs50 estimuló 41% la biomasa vegetal superior al testigo (P ≤ 0.5, Tukey). Se concluye que el Cs y AH no impactan significativamente el contenido iónico de la SS ni el contenido mineral de la biomasa, aunque si estimulan el rendimiento.