RESUMO: A batata-doce é uma cultura importante para a segurança alimentar com mercado mundial em ascensão. Com base nas alterações fisiológicas das plantas em resposta às condições climáticas e à fertilização, este estudo avaliou os efeitos da época de cultivo (período chuvoso e seco) e de doses de P2O5 (0, 50, 100, 200 e 400 kg ha-1) na produtividade total e por classes comerciais, bem como, a composição química das raízes de armazenamento de duas cultivares de batata-doce. A produtividade de raízes tuberosas foi maior na estação chuvosa. As doses ótimas agronômica e econômica foram de 128 e 95 kg ha-1 de P2O5 para a cultivar Canadense. A cultivar Uruguaiana não respondeu a adubação fosfatada, mas suas raízes tiveram maiores teores de matéria seca, lipídios, fibras, açúcares totais e redutores e amido. O cultivo de batata-doce no período chuvoso com doses de até 100 kg ha-1 de P2O5 aumenta a produtividade de raízes em classes de maior valor econômico e com maiores teores de carboidratos. Estes resultados ajudam os produtores a planejarem o plantio e a colheita da batata-doce ao longo do ano e contribui para a gestão da aplicação de fertilizantes fosfatados. RESUMO batatadoce batata doce ascensão fertilização seco PO P P2O 0, 0 (0 50 20 40 ha1 ha 1 comerciais como batatadoce. doce. chuvosa 12 9 ha- Canadense fosfatada seca lipídios fibras amido 10 carboidratos fosfatados ( 5 2 4

ABSTRACT: Sweet potato is an important food security crop, and the world market for this root is on the rise. Based on the physiological changes in plants in response to climatic conditions and fertilization, this study evaluated the effects of the growing season (rainy and dry season) and P2O5 doses (0, 50, 100, 200 and 400 kg ha-1) on total yield, marketable classes yields, as well as chemical composition of storage roots of two sweet potato cultivars. The storage roots yield was greater in the rainy season. The optimum agronomic and economic doses were 128 and 95 kg ha-1 P2O5 for the cultivar Canadense. Cultivar Uruguaiana did not respond to phosphate fertilization, but its storage roots had higher contents of dry matter, lipids, fibers, total and reducing sugars, and starch. Sweet potato cultivation in the rainy season with doses up to 100 kg ha-1 P2O5 increase root yield in marketable size classes in higher economic value and with higher carbohydrate contents. The results can help producers schedule the planting and harvesting of sweet potatoes throughout the year and contribute to the seasonal management of phosphate fertilizer application. ABSTRACT crop rise fertilization PO P O P2O 0, 0 (0 50 20 40 ha1 ha 1 yields cultivars 12 9 ha- Canadense matter lipids fibers sugars starch 10 application ( 5 2 4

ABSTRACT: Plants’ physiology changes through the day because photoassimilates can increase water-soluble carbohydrate concentration in the afternoon compared to the morning. This study evaluated the harvest time effect on whole-plant corn silage morphological composition, particle size, fermentation profile, chemical composition, in vitro degradation, and estimated milk yield. A two-year agronomic assay was performed in a completely random design, and one experimental silo was produced by each parcel (n = 16). The afternoon harvest increased (P < 0.01) dry matter content compared to the morning harvest. Harvest time did not affect (P ≥ 0.32) corn grain, stalk, leaf proportion, and silage particle size. However, the morning harvest increased dry matter recovery (P = 0.01) and had no effect (P ≥ 0.10) on silage pH and concentrations of lactic and acetic acid compared to the afternoon harvest. In addition, afternoon harvest instead of morning harvest increased (P ≤ 0.05) silage starch, water-soluble carbohydrates, acid detergent lignin, and ether extract content and dry matter in vitro degradation. Controversially, treatments showed no effect (P ≥ 0.14) on silage energy concentration, estimated energy content, and milk yield. Thus, the morning harvest produces more silage dry matter, but the afternoon harvest improves corn silage’s nutritional value with no impact on estimated milk yield. ABSTRACT Plants watersoluble water soluble wholeplant whole plant composition size profile degradation yield twoyear two year design n 16. 16 . 16) P 0.01 001 0 01 0.32 032 32 grain stalk proportion However 0.10 010 10 addition 0.05 005 05 starch carbohydrates lignin Controversially 0.14 014 14 Thus silages s 1 0.0 00 0.3 03 3 0.1 0.

RESUMO: A fisiologia das plantas muda ao longo do dia porque os fotoassimilados podem aumentar a concentração de carboidratos solúveis em água à tarde em comparação com a manhã. Este estudo teve como objetivo avaliar o efeito do horário de colheita na composição morfológica da silagem de milho de planta inteira, tamanho de partícula, perfil de fermentação, composição química, degradação in vitro e estimativa da produção de leite. Um ensaio agronômico de dois anos foi realizado em delineamento inteiramente casualizado, e um silo experimental foi produzido por cada parcela (n = 16). A colheita da tarde aumentou (P < 0,01) o teor de matéria seca em relação à colheita da manhã. A época de colheita não afetou (P ≥ 0,32) a proporção de grãos, colmos e folhas do milho e o tamanho das partículas da silagem. Entretanto, a colheita da manhã aumentou (P = 0,01) a recuperação de matéria seca e não teve efeito (P ≥ 0,10) no pH da silagem e nas concentrações de ácido láctico e acético em comparação à colheita da tarde. Além disso, a colheita da tarde, em vez da colheita da manhã, aumentou (P ≤ 0,05) o amido da silagem, os carboidratos solúveis em água, a lignina detergente ácida e o teor de extrato etéreo e a degradação in vitro da matéria seca. Controversamente, os tratamentos não mostraram efeito (P ≥ 0,14) na concentração de energia da silagem, no conteúdo energético estimado e na produção de leite. Assim, a colheita da manhã produz mais matéria seca da silagem, mas a colheita da tarde melhora o valor nutricional da silagem de milho sem impacto na produção estimada de leite. RESUMO inteira partícula fermentação química leite casualizado n 16. 16 . 16) P 0,01 001 0 01 0,32 032 32 grãos Entretanto 0,10 010 10 disso 0,05 005 05 Controversamente 0,14 014 14 Assim 1 0,0 00 0,3 03 3 0,1 0,

Abstract Background: Maize landraces show remarkable diversity and environmental adaptability in Mexico. Nevertheless, few studies have explored physiological mechanisms used by different maize landraces to grow and yield in a particular agroecological region. Question: How do three landrace maize populations from contrasting maize races in southeastern Mexico, differ in their responses in terms of growth, chlorophyll fluorescence, and gas exchange? Studied species: Zea mays L. Study site and date: Yucatan, Mexico; 2017. Methods: The field experiment followed a complete randomized block design, with six replicates. Three contrasting maize landraces were evaluated as treatments. Response variables were vegetative traits, dry matter allocation, yield components, and maize physiological responses. Data were analyzed by one-way ANOVA and post hoc Tukey multiple comparison test (P ≤ 0.05). Results: Maize landraces showed differences in cycle length, plant morphology, and yield performance. The long cycle maize landrace Xnuc-naal, had tall plants that accumulated 17 and 21 % more dry matter than Xmejen-naal and Elotillo, respectively. The short-cycle maize landraces Elotillo and Xmejen-naal exhibit superior physiological responses leading to higher grain yields compared to the Xnuc-naal. Conclusions: The landrace Xnuc-naal stood out for its ability in forage production, whereas Elotillo and Xmejen-naal exhibited notable physiological efficiency in grain production in southeastern Mexico.

Resumen Antecedentes: Las razas nativas de maíz muestran una notable diversidad y adaptabilidad en México. Sin embargo, pocos estudios han explorado los mecanismos fisiológicos utilizados por las diferentes razas de maíz para crecer y producir en una región agroecológica en particular. Pregunta: ¿Cómo difieren en sus respuestas en cuanto a crecimiento, fluorescencia de la clorofila e intercambio de gases tres variedades de maíz que provienen de razas contrastantes del sureste de México? Especie estudiada: Zea mays L. Sitio y fecha del estudio: Yucatán, México; 2017. Métodos: El experimento de campo siguió un diseño de bloques completamente aleatorios, con seis repeticiones. Se evaluaron tres variedades nativas de maíz contrastantes como tratamientos. Las variables de respuesta fueron rasgos vegetativos, distribución de materia seca, componentes del rendimiento y respuestas fisiológicas de las variedades de maíz. Los datos fueron analizados mediante ANOVA de una vía y la prueba de comparación múltiple de Tukey (P ≤ 0.05). Resultados: Las variedades locales de maíz mostraron diferencias en la duración del ciclo, morfología de la planta y rendimiento. La variedad tardía Xnuc-naal, tuvo plantas altas que acumularon un 17 y 21 % más materia seca que Xmejen-naal y Elotillo, respectivamente. Las variedades precoces Elotillo y Xmejen-naal exhibieron una respuesta fisiológica superior que llevó a un rendimiento de grano superior al de Xnuc-naal. Conclusiones: La variedad de maíz Xnuc-naal destacó por su capacidad para la producción de forraje, mientras que Elotillo y Xmejen-naal demostraron una eficiencia fisiológica notable en la producción de grano en el sureste de México.

ABSTRACT Residues generated in sugarcane production such as biochar, originated from bagasse burning, are used as a fertilizer source, which can increase forage dry matter yield, as well as improving soil chemical attributes. The objective of this study was to evaluate the effects of using biochar from sugarcane bagasse burning and mineral fertilization, as well as their association, on the dry matter yield of Urochloa decumbens and on the chemical attributes of the soil. The design was randomized blocks, which consisted of eight treatments and four blocks. The treatments were: T1- mineral fertilization; T2- fertilization with limestone plus mineral fertilizer; T3- liming; T4- biochar; T5- biochar plus mineral fertilizer; T6- liming plus biochar; T7- double fertilization with biochar and T8- control. Association of mineral fertilizer and biochar was able to increase dry matter yield by up to 131% when compared to the control treatment during the first year. The use of fertilization strategies in the restoration of degraded area under U. decumbens does not interfere with soil chemical attributes, except for sulfur. source association blocks were T1 T T2 T3 T4 T5 T6 T7 T8 131 year U sulfur 13 1

RESUMO Resíduos gerados pela produção de cana-de-açúcar como o biochar, proveniente da queima do bagaço podem ser utilizados como fonte de fertilizante, podendo incrementar a produção de matéria seca de forrageira, bem como, dos atributos químicos do solo. O objetivo deste trabalho foi avaliar a utilização de biochar da queima do bagaço da cana-de-açúcar e da adubação mineral e associação de ambos, na produtividade de matéria seca de Urochloa decumbens, e nos atributos químicos do solo. O delineamento utilizado foi em blocos casualizados, composto por oito tratamentos, com quatro repetições. Os tratamentos foram: T1- adubação mineral; T2- adubação com calcário + fertilizante mineral; T3- calagem; T4- biochar; T5- biochar + adubação mineral; T6- calagem + biochar; T7- duas vezes a dose com biochar e T8- controle. A associação de fertilizante mineral com biochar foi capaz de aumentar a produção de matéria seca em até 131% quando comparado ao tratamento controle no primeiro ano. O emprego de diferentes estratégias de fertilização na recuperação de área degradada sob uso de Urochloa decumbens, não interfere nos atributos químicos do solo, com exceção do elemento enxofre. canadeaçúcar cana açúcar forrageira solo ambos decumbens casualizados repetições foram T1 T T2 T3 T4 T5 T6 T7 T8 131 ano enxofre 13 1

Abstract The use of silage is considered as a feeding strategy in animal production systems with ruminants during dry periods. The objective was to evaluate the yield and nutritive value in forage and silage of Mulato II grass (Urochloa hybrid) and two additives, at different regrowth ages. Ages of 3, 6 and 9 weeks and additives (orange peel and molasses) were evaluated in silages: 1) Mulato II (ME); 2) Mulato II + orange peel; 3) Mulato II + molasses and 4) Mulato II + orange peel + molasses. The variables were: yield (kg ha-1) of total dry matter (TDM) and by morphological component, plant height (PH, cm), leaf area index (LAI), CP, NDF, ADF and lignin in forage and silage; pH, brix degrees and DM (%) in silage. When the forage was harvested at nine weeks of regrowth, the highest DM yield was obtained (7 508 kg ha-1), while the CP content was higher in week three of regrowth (201 g kg-1), exceeding by 10 and 29% that found in the sixth and ninth weeks. The silages with additives presented the highest CP values and the lowest values of ADF, NDF and pH. The higher the age of regrowth, the higher the dry matter yields, while the nutritive value decreased; however, the use of orange peel and molasses in grass silages improved the nutritive value.

Resumen El uso de ensilados es considerado como estrategia de alimentación en los sistemas de producción animal con rumiantes en periodos de estiaje. El objetivo fue evaluar el rendimiento y valor nutritivo en forraje y ensilado de pasto Mulato II (Urochloa híbrido) y dos aditivos, a diferente edad de rebrote. Se evaluaron edades de 3, 6 y 9 semanas y aditivos (cáscara de naranja y melaza) en ensilados: 1) Mulato II (ME); 2) Mulato II + cáscara de naranja; 3) Mulato II + melaza y 4) Mulato II + cáscara de naranja + melaza, mediante un diseño de bloques completos al azar. Las variables fueron: rendimiento (kg ha-1) de materia seca total (MST) y por componente morfológico, altura de planta (AP, cm), índice de área foliar (IAF), PC, FDN, FDA y lignina en forraje y ensilado; pH, grados brix y MS (%) en ensilados. Al cosechar el forraje a la edad de rebrote de nueve semanas se obtuvo el mayor rendimiento de MS (7 508 kg ha-1), mientras que, el contenido de PC fue mayor en la semana tres de rebrote (201 g kg-1), superando en 10 y 29% a lo encontrado en la sexta y novena semana. Los ensilados con aditivos presentaron los valores mayores de PC y menores de FDA, FDN y pH. A mayor edad de rebrote se obtienen mayores rendimientos de MS, pero el valor nutritivo disminuye, sin embargo, el uso de la cáscara de naranja y melaza en ensilados de pasto mejora el valor nutritivo.

Abstract The state of Yucatan, known for its shallow Leptosol soils poses challenges to agriculture. Therefore, this study focused on examining ecophysiological attributes influencing the growth and yield determinants of six maize genotypes. The study assessed vegetative characteristics, growth rates, dry matter allocation, grain yield, and harvest index. All maize genotypes exhibited early maturity, a favorable trait under the climate conditions of Yucatan. Most genotypes exhibited superior growth rate and dry matter content when compared to the landrace Elotillo. Stem and grain were identified as the primary organs for dry matter accumulation, with 36% and 22% respectively. The highest grain yield was noted in hybrids Impacto and DK-390. This study provided valuable information for farmers in selecting suitable maize genotypes in Yucatan, although additional evaluations of different genotypes and management conditions are recommended.

Resumen El estado de Yucatán, conocido por sus suelos poco profundos de Leptosol plantea desafíos a la agricultura. Por lo tanto, este estudio se centró en examinar los atributos ecofisiológicos que influyen en los determinantes del crecimiento y rendimiento de seis genotipos de maíz. El estudio evaluó características vegetativas, tasas de crecimiento, distribución de materia seca, rendimiento de grano e índice de cosecha. Todos los genotipos de maíz mostraron madurez temprana, una característica favorable bajo las condiciones de clima de Yucatán. La mayoría de los genotipos exhibieron una tasa de crecimiento y un contenido de materia seca superiores en comparación con el genotipo nativo Elotillo. El tallo y el grano fueron identificados como los órganos primarios de acumulación de materia seca con 36% y 22%, respectivamente. El mayor rendimiento de grano se observó en los híbridos Impacto y DK-390. Este estudio proporcionó información valiosa para los agricultores al seleccionar genotipos de maíz adecuados en Yucatán, aunque se recomienda realizar evaluaciones adicionales con diferentes genotipos y condiciones de manejo.

Abstract Introduction. The amount of usable water is currently limited due to the deterioration of its sources and indiscriminate use. An alternative to this problem is producing under green houses, where it is possible to obtain better water use efficiency (WUE) by reducing crop evapotranspiration (ETc) without compromising its productive potential. Objective. To evaluate the effect of 3 levels of volumetric moisture content depletion in coir on the vegetative-generative behavior of hydroponic tomato and sweet pepper produced under greenhouse cultivation. Materials and methods. The study was conducted during August to December 2020 and January 2021, at Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. Three treatments were applied: 11, 22 and 32% of water depletion in the substrate. Morphophysiological and reproductive parameters such as: the leaf area (AF), the number of leaves (NH), width (AH) and length of the leaf (LH), the length (LT) and the diameter of the stem (DT), the number of nodes (NN), dry matter (DM), stomatal conductance (gs), crop evapotranspiration (ETc), water use efficiency (WUE), the total yield (Rt), the commercial (Rc) of first (F1), second (F2) and third (F3) and waste fruits (Fd) were evaluated. Results. In the tomato treatments (TT) there was no effect on NH, LT, LH and NN; on the other hand, differences were reported in AH, DT and in MS, with treatment TT11 obtaining the higher values. The sweet pepper (TC), the treatment TC11 was statistically superior to the other treatments in number (NH), width (AH) and length (LH) of the leaf, in number of nodes (NN), production of fresh (MF) and dry matter (MS) and in diameter of the stem (DT), while there were no differences between treatments in stem length (LT). There were no differences in ETc and Rt, for both crops, but there was a difference in the commercial yield once it was divided by quality of fruit, TT11 presented the highest production of first and second fruit quality, while treatment TC11 presented the highest production of first, second and third fruit quality. For both crops, there were significant differences between treatments in terms of stomatal conductance. TT11 and TC11 treatments obtained the highest value of EUA with 37.32 kg.m-3 and 21.46 kg.m-3, respectively. Conclusion. In both crops, treatments with 11 and 22% water depletion showed an adequate balance between vegetative and productive growth, which was reflected in greater production of better quality commercial fruits, less waste and greater WUE.

Resumen Introducción. El uso de agua dulce en agricultura se encuentra limitado debido al deterioro de sus fuentes y su uso indiscriminado. El riego deficitario en agricultura protegida es una alternativa para mejorar la eficiencia en el uso del agua, a través de la reducción de la evapotranspiración del cultivo, sin comprometer su potencial productivo. Objetivo. Evaluar el efecto de 3 niveles de agotamiento del contenido de humedad volumétrica en un sustrato de fibra de coco, sobre el comportamiento vegetativo-generativo de los cultivos de tomate y chile dulce hidropónicos en invernadero. Materiales y métodos. El estudio se realizó en la Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. En ambos cultivos se aplicaron 3 tratamientos con 11, 22 y 32% de agotamiento hídrico en el sustrato, en un diseño experimental en bloques completos al azar. Se evaluaron parámetros morfofisiológicos y productivos tales como área foliar (AF), número de hojas (NH), ancho (AH) y longitud de hoja (LH), longitud (LT) y diámetro del tallo (DT), número de nudos (NN), materia seca (MS), conductancia estomática (gs), evapotranspiración del cultivo (ETc), eficiencia de uso de agua (EUA), rendimiento de fruto comercial (Rc) de primera (F1), segunda (F2) y tercera (F3), fruto de desecho (Fd) y rendimiento total (Rt). Resultados. En los tratamientos en tomate (TT) no hubo efecto sobre el NH, LH, LT y NN; mientras que con TT11 se obtuvieron valores superiores en AH, DT y MS. En chile dulce (TC), el TC11 obtuvo mayor NH, AH, LH, NN, DT y MS que los demás tratamientos; mientras que no hubo diferencias entre tratamientos en LT. En ambos cultivos, no hubo efecto sobre la ETc y el Rt, sin embargo, con 11% de agotamiento se obtuvo mayor producción comercial de F1 y F2 por lo que consecuentemente hubo mayor EUA con 37,32 kg.m-3 y 21,46 kg.m-3, respectivamente. Para ambos cultivos, la gs fue diferente entre tratamientos. Conclusión. En ambos cultivos, los tratamientos con 11 y 22% de agotamiento hídrico evidenciaron un adecuado balance entre crecimiento vegetativo y productivo, que se reflejó en mayor producción de frutos comerciales de mejor calidad, menos desecho y mayor EUA.

Resumen: Los métodos de extracción de fitoquímicos convencionales presentan bajos rendimientos o largos tiempos de proceso. El ultrasonido ofrece alternativas para incrementar el rendimiento en extractos vegetales. El objetivo de este trabajo fue evaluar el efecto de tres métodos de extracción en rendimiento, composición de compuestos fenólicos, actividad antioxidante y estabilidad de extractos de hojas de Plectranthus amboinicus (oreganón). Los métodos de extracción usados fueron: convencional con agitación (EC), asistida con baño de ultrasonidos (EABU) y asistida con sonda de ultrasonido (EASU). Se usó una proporción 1:10 (p/v) orégano:etanol a 35 ± 2 °C. Los rendimientos se calcularon como materia seca del extracto (% ms). Se usó un modelo de pseudo-segundo orden para ajustar las curvas de extracción experimentales de los tres métodos y obtener los parámetros cinéticos. Se determinaron compuestos fenólicos totales (CFT) y actividad antioxidante (AA) mediante los métodos de Folin-Ciocalteau y DPPH, respectivamente. Se evalúo la estabilidad del CFT y AA durante el almacenamiento. La EASU aumentó 33.93 % el rendimiento en los extractos con respecto a EC. La mayor concentración de CFT (P ≤ 0.05) se obtuvo mediante EABU (10.32 mg EAG/ms) y para AA mediante EC (19.43 mg ET/g ms). El modelo cinético de pseudo-segundo orden ajustó adecuadamente las cinéticas experimentales. La constante de velocidad (k) de CFT más alta fue de 0.016 g ms/mg EAG·min para la EASU, siendo esta técnica la que demostró una disminución significativa de AA con respecto al tiempo de extracción. Los CFT de los extractos obtenidos mediante EABU, EASU y EC (3.7 mg EAG/g ms, 4.4 mg EAG/g ms y 7.2 mg EAG/g ms, respectivamente), al igual que la AA se mantuvieron estables y sin cambios significativos (P ≥ 0.05) durante los 34 d de almacenamiento, mostrando nuevamente la ventaja de utilizar la técnica extractiva de ultrasonidos, en función del tiempo.

Abstract: Conventional phytochemicals extraction methods have shown low yields or very long processing times for obtaining. The ultrasound offers alternatives to increase the yields of plant extracts. The objective of this work was to evaluate the effect of three extraction methods on the yield, phenolic compound composition, antioxidant activity and stability of Plectranthus amboinicus (oregano) leaf extracts. The extraction methods used were: conventional heat-assisted extraction (CE), ultrasound water bath assisted (UBAE) and ultrasound probe assisted extraction (UPAE). A 1:10 (w/v) oregano:ethanol ratio was used at 35 ± 2 °C. Yields were calculated as extract dry matter (% ms). A pseudo-second-order model was used to fit the experimental extraction curves of the three methods and obtain the kinetic parameters. Total phenolic compounds (TPC) and antioxidant activity (AA) were determined by Folin-Ciocal-teau and DPPH methods, respectively. The stability of TPC and AA was evaluated during storage. UPAE increased 33.93 % yield in extracts concerning CE. The highest concentration of CFT (P ≤ 0.05) was obtained by UBAE (10.32 mg EAG/ms) and for AA by CE (19.43 mg ET/g ms). The pseudo-second-order kinetic model adequately fitted the experimental kinetics. The highest TPC rate constant (k) was 0.016 g ms/mg EAG·min, for UPAE, this technique being the one that demonstrated a significant decrease in AA with respect to extraction time. The TPC of the extracts obtained by UBAE, UPAE and CE (3.7 mg EAG/g dms, 4.4 mg EAG/g dms and 7.2 mg EAG/g ms, respectively), as well as the AA remained stable and without significant changes (P ≥ 0.05) during the 34 d of storage, again showing the advantage of using the ultrasound extractive technique, as a function of time.

Abstract The objective was to evaluate the dry matter (DM) accumulation by component, yield, and nutritional composition of forage of four corn hybrids harvested at 121, 128, 135 and 142 d after sowing. In each harvest, five plants were randomly taken and separated into their components (stem, leaves, grain, cob, bracts, and tassel) and DM was determined; chemical composition and in-situ digestibility were analyzed in a composite sample of a whole plant. The accumulation of grain in the total DM increased from 35.8 to 43.9 % from 121 to 142 d to harvest, respectively, and diluted the other components, especially the proportion of stem and leaves, which decreased inversely proportional to the accumulation of grain. Total DM content differed between hybrids, from 3.8 and up to 8.3 percentage units on the same days to harvest. Nonetheless, the hybrid did not affect DM yield or grain production, increasing by 2.1 and 1.4 t ha-1 between harvests, respectively. NDF content decreased and starch increased (both linearly), affecting net energy for lactation, which increased from 1.49 to 1.56 Mcal kg-1 from 121 to 142 d to harvest, respectively. The interaction between days to harvest and hybrid affected starch content, which was 5.2 units higher in a hybrid with similar NFC and NDF content than its counterparts. DM, NDF and starch digestibilities were affected by the hybrid, but not by the days to harvest.

Resumen El objetivo fue evaluar la acumulación de materia seca (MS) por componente, rendimiento y composición nutricional del forraje de cuatro híbridos de maíz cosechados a 121, 128, 135 y 142 días después de la siembra. En cada cosecha, se tomaron al azar cinco plantas y se separaron en sus componentes (tallo, hojas, grano, olote, brácteas y espiga) y se determinó la MS; en una muestra compuesta de planta completa se analizó la composición química y digestibilidad in situ. La acumulación de grano en la MS total se incrementó de 35.8 a 43.9 % de los 121 a 142 días a cosecha, respectivamente, y diluyó a los demás componentes, sobre todo la proporción de tallo y de hojas, que decrecieron inversamente proporcional a la acumulación de grano. El contenido de MS total difirió entre híbridos de 3.8 y hasta 8.3 unidades porcentuales a mismos días a cosecha. Sin embargo, el híbrido no afectó el rendimiento de MS ni la producción de grano incrementándose 2.1 y 1.4 t ha-1 entre cosecha, respectivamente. El contenido de FDN disminuyó y el almidón se incrementó (ambos linealmente), afectando la energía neta de lactancia que aumentó de 1.49 a 1.56 Mcal kg-1 de los 121 a 142 días a cosecha, respectivamente. La interacción entre días a cosecha e híbrido afectó el contenido de almidón, el cual fue 5.2 unidades superior en un híbrido con similar contenido de CNF y FDN que sus contrapartes. Las digestibilidades de la MS, de la FDN y del almidón fueron afectadas por el híbrido, pero no por los días a cosecha.

ABSTRACT Given genetical coefficients need to be calibrated for the most important cultivars on the market, new cultivars must be added to models such as SimulArroz. Thus, the aim of this study was to calibrate and evaluate the SimulArroz model for two new irrigated rice cultivars. The experiments were conducted in the municipality of Goianira in Goiás state during four growing seasons (2014/15, 2015/16, 2016/17, 2017/18) and in Rio Grande do Sul state in the municipalities of Alegrete (2015/16), Cachoeirinha (2015/ 16), Capão do Leão (2016/17, 2017/18), Santa Vitória do Palmar (2017/18) and Uruguaiana (2014/15, 2015/16). A randomized block design was used, with four replicates in Rio Grande do Sul and sowing plots in Goianira. The BRS Catiana and BRS Pampa cultivars were used and the Haun stage (HS), phenology, shoot dry matter biomass and yield were evaluated. The root mean square error (RMSE) for above-ground dry matter ranged from 51.7 to 577 g m-2, and for yield, the normalized root mean square error (NRMSE) ranged from 24 to 32% and 22 to 35% for the potential and high technological levels, respectively. The SimulArroz model was able to satisfactorily predict the growth, development, and yield of the BRS Catiana and BRS Pampa cultivars, increasing their area of application, including the tropical region of Brazil. market Thus 2014/15, 201415 2014 15 (2014/15 201516 2015 16 2015/16 201617 2016 17 2016/17 2017/18 201718 2017 18 , (2015/16) 2015/ (2015 16, 16) (2016/17 2017/18, (2017/18 2015/16. . 2015/16) HS, HS (HS) phenology evaluated RMSE (RMSE aboveground above ground 517 51 7 51. 57 m2, m2 m 2, 2 m-2 NRMSE (NRMSE 32 35 levels respectively growth development application Brazil 2014/15 20141 201 1 (2014/1 20151 2015/1 20161 2016/1 2017/1 20171 (2015/16 (201 (2016/1 (2017/1 (HS 5 m- 3 2014/1 20 (2014/ 2016/ 2017/ (2015/1 (20 (2016/ (2017/ 2014/ (2014 (2 (2016 (2017 (

RESUMO Os coeficientes genéticos precisam ser calibrados para as cultivares mais representativas do mercado, portanto, é necessário adicionar novas cultivares a modelos como o SimulArroz. Portanto, o objetivo deste estudo foi calibrar e avaliar o modelo SimulArroz para duas novas cultivares de arroz irrigado. Os experimentos foram conduzidos no município de Goianira em Goiás durante quatro safras (2014/15, 2015/16, 2016/17, 2017/18) e no Rio Grande do Sul nos municípios de Alegrete (2015/16), Cachoeirinha (2015/16), Capão do Leão (2016/17, 2017/18), Santa Vitória do Palmar (2017/18) e Uruguaiana (2014/15, 2015/16). O delineamento utilizado foi o de blocos casualizados, com quatro repetições no Rio Grande do Sul e com parcelas de semeadura em Goianira. Foram utilizadas as cultivares BRS Catiana e BRS Pampa, sendo avaliadas o estádio Haun (HS), fenologia, biomassa de matéria seca da parte aérea e produtividade. A raiz do erro quadrático médio (RMSE) para matéria seca aérea variou de 51,7 a 577 g m-2, e para produtividade, a raiz do erro quadrático médio normalizado (NRMSE) variou de 24 a 32% e 22 a 35% para o potencial e alto nível tecnológico, respectivamente. O modelo SimulArroz foi capaz de prever satisfatoriamente o crescimento, desenvolvimento e produtividade para as cultivares BRS Catiana e BRS Pampa, aumentando sua área de aplicação e abrangendo também a região tropical do Brasil. mercado portanto Portanto irrigado 2014/15, 201415 2014 15 (2014/15 201516 2015 16 2015/16 201617 2016 17 2016/17 2017/18 201718 2017 18 , (2015/16) (2016/17 2017/18, (2017/18 2015/16. . 2015/16) casualizados Pampa HS, HS (HS) fenologia RMSE (RMSE 517 51 7 51, 57 m2, m2 m 2, 2 m-2 NRMSE (NRMSE 32 35 tecnológico respectivamente crescimento Brasil 2014/15 20141 201 1 (2014/1 20151 2015/1 20161 2016/1 2017/1 20171 (2015/16 (2016/1 (2017/1 (HS 5 m- 3 2014/1 20 (2014/ 2015/ 2016/ 2017/ (2015/1 (2016/ (2017/ 2014/ (2014 (2015/ (2016 (2017 (201 (2015 (20 (2 (

Abstract Tomato (Solanum lycopersicum, L.) is the most important vegetable in the world in terms of production volumes, which will have to continue to increase to meet future consumption needs. In this regard, the use of nanotechnology could make the supply of nutrients to plants more efficient and improve and increase agricultural production. The objective of the study was to determine the effect of foliar application of Zn, Cu, and Fe nanoparticles on tomato production and quality. In 2021, a Roma-type tomato crop was established under protected agriculture. The treatments consisted of the individual and combined foliar application of nanoparticles of Zn, Fe, Cu, Zn+Fe, Zn+Cu, Fe+Cu, Zn+Fe+Cu, plus a control without application. It was found that the individual application of the nanoparticles did not improve tomato production, however, the combined supply increased the yield. The highest production was recorded with Zu+Fe+Cu, which was 66% higher than the control plants, with this treatment the lycopene content also doubled (2.23 mg g-1 dry matter). The nanoparticles increased the nutrient content within the maximum limit allowed for consumption. Therefore, the application of micronutrient nanoparticles supplied in combination is a viable alternative to improve tomato yield and quality.

Resumen El tomate (Solanum lycopersicum, L.) es la hortaliza de mayor importancia a nivel mundial por volúmenes de producción, que deberá seguir aumentando para satisfacer la necesidad de consumo futuro. Al respecto, el uso de la nanotecnología podría eficientar y mejorar el aporte de nutrientes a las plantas y aumentar la producción agrícola. El objetivo del estudio fue determinar el efecto de la aplicación foliar de nanopartículas de Zn, Cu y Fe, sobre la producción y calidad del tomate. En el año 2021 se estableció el cultivo de tomate tipo roma en agricultura protegida. Los tratamientos consistieron en la aplicación foliar individual y en combinación de nanopartículas de Zn, Fe, Cu, Zn+Fe, Zn+Cu, Fe+Cu, Zn+Fe+Cu, más un testigo sin aplicación. Se encontró que la aplicación individual de las nanopartículas no mejoró la producción de tomate; sin embargo, el suministro combinado aumentó el rendimiento. La mayor producción se registró con Zu+Fe+Cu, que fue 66% superior a las plantas del testigo, con este tratamiento también aumentó al doble el contenido de licopeno (2.23 mg g-1 de materia seca). Las nanopartículas aumentaron el contenido nutrimental dentro del límite máximo permitido para consumo. Por lo que la aplicación de nanopartículas de micronutrientes suministradas en combinación es una alternativa viable para mejorar el rendimiento y la calidad del tomate.

A comprehensive field investigation was conducted to enhance the productivity, profitability, and water use efficiency (WUE) of summer okra through the optimization of irrigation and nitrogen fertilizer application. The study involved 3 irrigation levels -0.75 Epan (pan evaporation) as I1, 1.00 Epan as I2, and 1.25 Epan as I3- as the main plot factors, and 4 nitrogen concentrations - 75% recommended nitrogen dose (RDN) as N1, 100% RDN as N2, 125% RDN as N3, and 150% RDN as N4- as the subplot variables. The results of the study revealed a significant influence of irrigation and nitrogen levels on various key parameters. Above-ground dry matter, yield, plant height, WUE, net returns, and benefit-to-cost ratio (B:C) exhibited an incremental trend with increasing irrigation and nitrogen levels, up to a certain threshold. Beyond this threshold, further increments in irrigation and nitrogen led to diminishing returns. The models developed for estimating crop yield, above-ground drv matter, plant height, WUE, net returns, and B:C demonstrated impressive accuracy, with high coefficients of determination (R²) and satisfactory precision. The optimized irrigation level (crop evapotranspiration, ET C) ranged from 418.39-441.23 mm. At the same time, the ideal nitrogen application rate was found to be in the range of 167.04-176.13 kg N/ha. These optimal conditions resulted in peak crop yield of 28 295 kg/ha, above-ground dry matter of 6 709.1 kg/ha, plant height of 66.3 cm, WUE of 5.26 kg/m³, B:C of 4.54, and net returns amounting to 441 133 INR/ha. In conclusion, the application of response surface methodology facilitated the identification of the impact of each factor on individual responses, as well as the determination of optimal conditions that simultaneously maximize multiple desirable outcomes. These findings hold significant promise for improving the cultivation of summer okra while optimizing resource use and economic returns.

Abstract: This study compared forage yield and agronomic characteristics of 9 maize cultivars (Pioneer 30N11, Pioneer 4444, Pioneer 30K08, SC-128W, SC-166Y, SC-78Y, TWC-324W, TWC-368Y and TWC- 321W) ensiled with or without urea as for ruminants on in vitro ruminal fermentation characteristics and nutrient degradability. A factorial randomized complete block design was used. Pioneer 30N11 and Pioneer 4444 showed the greatest silage forage yield, ear weight, and plant height. The chemical composition of maize silage cultivars without urea revealed that Pioneer 30K08 had the greatest (P<0.001) crude protein (CP) content (127 g/kg), while the lowest CP content (89 g/kg) was observed with SC-78Y. CP content ranged from 118 to 156 g/kg when urea was added to the maize silage cultivars. The neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents recorded the highest values (P<0.01) in TWC-324W, SC-128W and SC-78Y. Urea treatment of different cultivars affected (P<0.05) the concentrations of CP, ether extract (EE), non-structural carbohydrates (NSC), and fibers. Urea treatment increased CP and EE in all cultivars and increased or decreased truly degraded dry matter (TDDM), truly degraded organic matter (TDOM), protozoa, ammonia and methane (P<0.05). Overall, Pioneer 30N11, Pioneer 4444 and Pioneer 30K08 showed the greatest forage yield and nutritive value as a feed for ruminants.

ABSTRACT The use of nanoparticles (NPs) in agriculture offers diverse applications, with a noteworthy emphasis on enhancing production rates and elevating the nutritional values of plants. This study specifically explores the foliar application of zinc oxide nanoparticles (ZnO NPs) in Lactuca sativa L. var. longifolia cultivated through a hydroponic system utilizing the nutrient film technique (NFT). The research was carried out during the autumn-winter cycle of 2022-2023. The main objective of this research was to assess the impact of NPs ZnO on yield, bioactive compounds, and enzymatic activity in lettuce. The treatments under evaluation included a control treatment (0) and four equidistant doses of 10, 20, 30, and 40 mg L-1 of nanoparticles. The experimental design employed was completely randomized. The results obtained indicate a significant increase in the concentration of zinc (Zn2+) in plants with the application of ZnO NPs, resulting in a heightened production of beneficial metabolites for the crop. Remarkably, the concentration of 40 mg L-1 of ZnO NPs demonstrated significant improvements in comparison to the control treatment across all evaluated variables: fresh weight, dry matter, zinc content, total chlorophyll, total carotenoids, total phenolics, antioxidant capacity, total flavonoids, vitamin C, catalase and peroxidase. These findings suggest that this specific dose could be optimal for achieving maximum benefits. In conclusion, foliar application of ZnO NPs emerges as a practical approach to enrich lettuce plants and alleviate micronutrient deficiencies in the population.

RESUMEN El uso de nanopartículas (NPs) en la agricultura presenta diversas aplicaciones, entre las cuales se destaca el potencial para aumentar las tasas de producción y mejorar los valores nutricionales de las plantas. Este estudio se centra en la aplicación foliar de nanopartículas de óxido de zinc (NPs-ZnO) en plantas de Lactuca sativa L. var. longifolia producidas en un sistema hidropónico con la técnica de película de nutrientes (NFT). La investigación se llevó a cabo durante el ciclo otoño-invierno 2022-2023. El objetivo principal de la investigación fue evaluar el impacto de las NPs-ZnO sobre el rendimiento, compuestos bioactivos y actividad enzimática en lechuga. Los tratamientos evaluados fueron: tratamiento control (0) y cuatro dosis equidistantes de 10, 20, 30 y 40 mg L-1 de nanopartículas; el diseño utilizado fue completamente al azar. Los resultados revelan que la concentración de zinc (Zn2+) en las plantas aumenta significativamente con la aplicación de NPs-ZnO, lo que conlleva a mayor producción de metabolitos beneficiosos para el cultivo. Es destacable que la concentración de 40 mg L-1 de NPs-ZnO haya mostrado mejoras significativas con respecto al tratamiento control en todas las variables evaluadas; peso fresco, materia seca, contenido de zinc, clorofila total, carotenoides totales, fenoles totales, capacidad antioxidante, flavonoides totales, vitamina C, catalasa y peroxidasa, sugiriendo que esta dosis específica podría ser óptima para obtener máximos beneficios. Por lo tanto, la aplicación foliar de NPs ZnO es una manera práctica de enriquecer las plantas de lechuga y mitigar las deficiencias de este micronutriente en la población.

ABSTRACT The chemical characteristics of Cenchrus clandestinus grass, nutritional base in dairy production systems, demand the energy supplementation. Corn grain is the most used food for this purpose, but considering its demand and prices, the aim of this study was to evaluate its partial replacement by alternative non-fibrous carbohydrates sources on methane emissions, energy and nitrogen balance and productive performance of dairy cows. Sixteen multiparous Holstein cows were fed Cenchrus clandestinus plus one of four concentrate supplements formulated with corn (Zea mays) or a partial replacement of corn with sorghum (Sorghum vulgare), cassava (Manihot esculenta) or citrus pulp (Citrus sp). Inclusion of these ingredients did not affect dry matter intake, dry matter digestibility, enteric methane emissions, energy and nitrogen balance, milk yield or composition. The results allow to conclude that these ingredients can partially replace corn in the diet of lactating dairy cows.

RESUMEN Las características químicas del pasto Cenchrus clandestinus, base alimenticia en los sistemas de producción lechera, hacen necesaria la suplementación energética. El grano de maíz es el alimento más empleado para este propósito, pero dada su demanda y precio, el objetivo de este trabajo fue evaluar su reemplazo parcial por otras fuentes de carbohidratos no fibrosos sobre la emisión de metano, el balance energético-nitrogenado y el desempeño productivo de vacas lecheras. Dieciséis vacas Holstein recibieron Cenchrus clandestinus y uno de cuatro concentrados formulados con maíz (Zea mays) y sorgo (Sorghum vulgare), yuca (Manihot esculenta) o pulpa cítrica (Citrus sp) en reemplazo parcial del maíz. La inclusión de estos ingredientes no alteró el consumo de materia seca ni su digestibilidad, producción de metano, balance energético-nitrogenado, producción de leche o su composición. Los resultados permiten concluir que esos ingredientes pueden reemplazar parcialmente al maíz en la dieta de vacas lecheras.