Abstract Introduction. Corn (Zea mays) is widely used in animal feed, either as grain, green fodder or silage. Objective. To evaluate the yield and nutritional quality of 6 Costa Rican corn varieties selected for grain production. Materials and methods. The study was conducted at 4 experimental sites (Aguas Zarcas, Turrialba, San Luis de Monteverde and Guápiles) between September and December 2018. At each site, a randomized complete block design with 4 replications and 8 treatments (6 varieties and 2 corn hybrids). Plant height was evaluated, Dry Mass (DM) production, chemical composition and in vitro DM digestibility at forage harvest were evaluated. Results. Plant height and DM production were affected by treatments. Yields of the Costa Rican DM varieties EJN2, Upiav-G6, Los Diamantes 8843 and JSáenz (12.7-14 t.ha-1) were similar to the forage hybrid CLTHY002 (13.5 t.ha-1). Only DM and CP content varied in the treatments. Conclusions. The Costa Rican corn varieties EJN2, Los Diamantes 8843, JSáenz and Upiav-G6, have potential to be used as a forage source for animal feeding because they achieved yields and nutritive values like those obtained with the hybrids selected by Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) for forage production.

Resumen Introducción. El cultivo de maíz (Zea mays) es ampliamente utilizado en la alimentación animal, tanto en forma de grano, como forraje verde o ensilaje. Objetivo. Evaluar la producción y calidad nutritiva de 6 variedades de maíces costarricenses seleccionados para la producción de grano. Materiales y métodos. El estudio se realizó en 4 sitios experimentales (Aguas Zarcas, Turrialba, San Luis de Monteverde y Guápiles) entre setiembre y diciembre del 2018. En cada sitio, se trabajó con un diseño de bloques completos al azar con 4 repeticiones y 8 tratamientos (6 variedades y 2 híbridos de maíces). Se evaluó la altura de la planta, la producción de materia seca (MS), la composición química y la digestibilidad in vitro de la MS a la cosecha de los forrajes. Resultados. La altura de la planta y la producción de MS fueron afectadas por los tratamientos. Los rendimientos de MS de las variedades costarricenses EJN2, Upiav-G6, Los Diamantes 8843 y JSáenz (12,7-14 t.ha-1) fueron semejantes al híbrido forrajero CLTHY002 (13,5 t.ha-1). Solamente el contenido de MS y PC varío entre los tratamientos. Conclusión. Las variedades de maíces costarricenses EJN2, Los Diamantes 8843, JSáenz y Upiav-G6, tienen potencial para ser utilizadas como fuente forrajera para la alimentación de rumiantes, ya que alcanzaron rendimientos y valores nutritivos semejantes a los obtenidos con los híbridos seleccionados por el Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) para la producción de forrajes.

Abstract: Corn drying reduces the moisture content present in the grain to levels that allow safe storage. This process requires a large amount of energy, which is why, if not applied correctly, it can affect the quality of the product to be dried, in addition to representing important costs in the operation of the drying plants. The objective of this research is to analyze the corn drying systems used in Canton Quevedo, Province of Los Ríos. In order to achieve the objective, field visits were made to the area under study, considering factors related to the technology used and the corn harvesting period, as well as, characteristics of the coastal region of Ecuador. It was determined that stationary or fixed bed drying is the drying system widely used for corn drying, which uses subsidized liquefied petroleum gas as fuel for its operation. The moisture content of the corn received at the drying plants is above 30% in the two harvesting periods of the product, a situation that has an impact on processing times and product quality. The fuel demand for drying an average mass of product of 60.2 tons, between the first harvest period, March - June, and the second period, September - November, presents a difference of 300.77 kg of LPG in relation to the first harvest, being the moisture content a key factor to take into account.

Resumen: El secado del maíz permite reducir el contenido de humedad presente en el grano a niveles que permitan un almacenamiento seguro. El objetivo de esta investigación permite analizar los sistemas de secado de maíz empleados en el Cantón Quevedo, Provincia de Los Ríos. Para alcanzar nuestro objetivo se realizaron visitas de campo en la zona objeto de estudio, por lo que se consideraron factores relacionados con la tecnología empleada y período de cosecha de maíz, características de la región costera del Ecuador. Se determinó que el secado estacionario o de lecho fijo es el sistema de secado ampliamente empleado para el secado de maíz, el cual emplea como combustible el gas licuado de petróleo subsidiado para su funcionamiento. La humedad de recibo de maíz en las plantas de secado presenta niveles de humedad por encima del 30 %, en los dos periodos de cosecha del producto, situación que repercute en los tiempos de proceso y en la calidad del producto. La demanda de combustible para secar una masa promedio de producto, 60,2 Ton, entre el primer período de cosecha que va de Marzo - Junio, y el segundo período, Septiembre - Noviembre, presenta una diferencia de 300,77 Kg de GLP con relación a la primera cosecha, siendo la humedad de recibo un factor clave a tomar en cuenta.

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 The use of corn hybrids adapted to the soil and climate conditions of the cultivation region under adequate optimum plant density is a determining factor for the maximization of grain yield. In this sense, the objective was to evaluate the productivity of corn hybrids under two sowing densities during the 2020/21 crop season in the medium-high Uruguay region of the state of Rio Grande do Sul. The corn hybrids AS1555 PRO3, B2401 PWU, B2418 VYHR, B2612 PWU, BG7061 YHR, DKB235 PRO3, NS45 VIP3, NS73 VIP3, NS80 VIP3, P2501, P3016 VYHR, P3565 PWU and 30F53 VYHR were submitted to densities of 66,667 and 88,889 plants ha-1, in a randomized block design with ten replications. Corn hybrids showed superior grain yield when subjected to the density of 88,889 plants ha-1 in the medium-high Uruguay region of Rio Grande do Sul, surpassing in most cases the state and national average yield of harvest 2020/21. Most of the corn hybrids used present potential for cultivation at higher sowing density than their respective recommendations. Considering the superior productivity of hybrids NS80 VIP3, B2401 PWU and NS73 VIP3, their cultivation under conditions similar to those of the study is recommended. sense 202021 2020 21 2020/2 mediumhigh medium high Sul AS AS155 PRO3 PRO B B240 B241 B261 BG BG706 YHR DKB DKB23 NS NS4 VIP3 VIP NS7 NS8 P2501 P P301 P356 F 30F5 66667 66 667 66,66 88889 88 889 88,88 ha1, ha1 ha 1, 1 replications ha- recommendations recommended 20202 202 2 2020/ AS15 B24 B26 BG70 DKB2 P250 P30 P35 30F 6666 6 66,6 8888 8 88,8 20 AS1 B2 BG7 P25 P3 666 66, 888 88, P2

Abstract The cotton or solenopsis mealybug, Phenacoccus solenopsis (Tinsley, 1898) (Hemiptera: Pseudococcidae), infests various host plants in Egypt. A study was conducted to observe the incidence of mealybugs and the possible influences of meteorological variables and plant age on the insect population of maize (single-hybrid 168 yellow maize cultivar) plants in Esna district, Luxor governorate, Egypt, in two consecutive seasons (2021 and 2022). P. solenopsis infested maize plants from the 3rd week of June to harvest, and had three peaks of seasonal incidence/season namely; in the 1st week of June in the 3rd/4th week of July, and the 2nd week of August. Similarly, there were three peaks in the percent of infestations per season. In the first season, the average population density of P. solenopsis per sample was 174.04 ± 16.93 individuals, and in the second season, 156.72 ± 14.28 individuals. The most favorable climate for P. solenopsis population increase and infestation occurred in August in the first season and in September in the second season, while June was less suitable in both growing seasons (as estimated by weekly surveys). The combined effects of weather conditions and plant age are significantly related to the estimates of P. solenopsis populations, with an explained variance (E.V.) of 93.18 and 93.86%, respectively, in the two seasons. In addition, their influences explained differences in infestation percentages of 93.30 and 95.54%, respectively, in the two seasons. Maize plant age was the most effective factor in determining changes in P. solenopsis population densities in each season. The mean daily minimum temperature in the first season and mean daily dew point in the second season were the most important factors affecting the percent changes in infestation. However, in both seasons, the mean daily maximum temperature was the least effective variable in population and infestation variation. This study paves the way for monitoring and early detection of mealybugs in maize; as well as the optimal climatic conditions for its development. mealybug Tinsley, Tinsley (Tinsley 1898 Hemiptera (Hemiptera Pseudococcidae, Pseudococcidae , Pseudococcidae) Egypt singlehybrid single hybrid 16 cultivar district governorate 2021 (202 2022. 2022 . 2022) P rd harvest incidenceseason namely st 3rd4th rdth 4th th July nd Similarly 17404 174 04 174.0 1693 93 16.9 individuals 15672 156 72 156.7 1428 14 28 14.2 surveys. surveys surveys) populations E.V. EV E V (E.V. 9318 18 93.1 9386 86 93.86% respectively addition 9330 30 93.3 9554 95 54 95.54% However variation development 189 1 202 (20 1740 17 0 174. 169 9 16. 1567 15 7 156. 142 2 14. E.V (E.V 931 93. 938 8 93.86 933 3 955 5 95.54 20 (2 93.8 95.5 ( 95.

Resumo A cochonilha do algodão ou solenopsis, Phenacoccus solenopsis (Tinsley, 1898) (Hemiptera: Pseudococcidae), infesta várias plantas hospedeiras no Egito. Um estudo foi conduzido para observar a incidência de cochonilhas e as possíveis influências de variáveis meteorológicas e da idade da planta na população de insetos de plantas de milho (cultivar de milho amarelo 168 híbrido único) no distrito de Esna, província de Luxor, Egito, em duas temporadas consecutivas (2021 e 2022). P. solenopsis infestou plantas de milho desde a terceira semana de junho até a colheita, e teve três picos de incidência/estação sazonal, a saber: na primeira semana de junho, nas terceira e quarta semanas de julho e na segunda semana de agosto. Da mesma forma, ocorreram três picos na percentagem de infestações por estação. Na primeira temporada, a densidade populacional média de P. solenopsis por amostra foi de 174,04 ± 16,93 indivíduos, e na segunda temporada, 156,72 ± 14,28 indivíduos. O clima mais favorável ao aumento populacional e à infestação de P. solenopsis ocorreu em agosto na primeira época e em setembro na segunda época, enquanto junho foi menos adequado em ambas as épocas de cultivo (conforme estimado por inquéritos semanais). Os efeitos combinados das condições climáticas e da idade das plantas estão significativamente relacionados com as estimativas das populações de P. solenopsis, com variância explicada (E.V.) de 93,18 e 93,86%, respectivamente, nas duas estações. Além disso, suas influências explicaram diferenças nos percentuais de infestação de 93,30 e 95,54%, respectivamente, nas duas épocas. A idade da planta de milho foi o fator mais eficaz na determinação das mudanças nas densidades populacionais de P. solenopsis em cada estação. A temperatura mínima diária média na primeira época e o ponto de orvalho médio diário na segunda época foram os fatores mais importantes que afetaram as alterações percentuais na infestação. Porém, em ambas as estações, a temperatura máxima média diária foi a variável menos eficaz na variação populacional e de infestação. Este estudo abre caminho para o monitoramento e a detecção precoce de cochonilhas no milho, bem como as condições climáticas ideais para o seu desenvolvimento. Tinsley, Tinsley (Tinsley 1898 Hemiptera (Hemiptera Pseudococcidae, Pseudococcidae , Pseudococcidae) Egito cultivar 16 único Esna Luxor 2021 (202 2022. 2022 . 2022) P colheita incidênciaestação estação sazonal saber forma temporada 17404 174 04 174,0 1693 93 16,9 indivíduos 15672 156 72 156,7 1428 14 28 14,2 conforme semanais. semanais semanais) E.V. EV E V (E.V. 9318 18 93,1 9386 86 93,86% respectivamente estações disso 9330 30 93,3 9554 95 54 95,54% Porém desenvolvimento 189 1 202 (20 1740 17 0 174, 169 9 16, 1567 15 7 156, 142 2 14, E.V (E.V 931 93, 938 8 93,86 933 3 955 5 95,54 20 (2 93,8 95,5 ( 95,

ABSTRACT The aim of this study was to evaluate the yield, the morphometric characteristics, and the nutritional value of corn with use of foliar fungicide associated with inoculant on ensiling on the chemical-fermentative characteristics of silage. The applications of fungicide pyraclostrobin + fluxpyroxade were carried out in vegetative-eight and tasseling stage, and the evaluations of plants occurred simultaneously at harvest (dough grain stage), during which application was made with inoculant consisting of strains of Lactobacillus buchneri and L. casei for silage production. The use of fungicide decreased the percentage of leaf area affected by Diplodia macrospora Earle, Cercospora zeae-maydis and Phaeosphaeria maydis. At harvest, corn showed fewer dry leaves and higher yields of fresh (66,368vs. 62,015kg·ha-1) and dry biomass (20,964 vs. 19,485kg·ha-1) with fungicide. The fungicide also reduced the LDA content from 5.99% to 5.16%, which generated greater ISDMD for whole plant (43.14 and 62.57%, for 24 and 48 hours, respectively). The association of fungicide with inoculant promoted higher concentration of acetic acid than when each was used alone, and the dry matter losses of silage with inoculant were higher than control silage (8.88vs. 12.78%, respectively). Fungicide and inoculant used in combination provided silages with lower fibrous content. yield chemicalfermentative chemical fermentative vegetativeeight vegetative eight stage dough , stage) L production Earle zeaemaydis zeae maydis 66,368vs. 66368vs vs 66 368vs (66,368vs 62,015kg·ha1 62015kgha1 kgha 62,015kg·ha 1 62 015kg ha kg 62,015kg·ha-1 20,964 20964 20 964 (20,96 19,485kg·ha1 19485kgha1 19,485kg·ha 19 485kg 19,485kg·ha-1 599 5 99 5.99 516 16 5.16% 43.14 4314 43 14 (43.1 6257 57 62.57% 2 4 hours respectively. respectively . respectively) alone 8.88vs. 888vs 8 88vs (8.88vs 1278 12 78 12.78% 66,368vs 6 ha1 62015kgha 62,015kg·ha- 20,96 2096 96 (20,9 19485kgha 19,485kg·ha- 59 9 5.9 51 5.16 43.1 431 (43. 625 62.57 8.88vs 127 7 12.78 20,9 209 (20, 5. 5.1 43. (43 62.5 12.7 20, (20 (4 62. 12. (2 (

RESUMO O objetivo deste estudo foi avaliar a produtividade, as características morfométricas e o valor nutricional do milho, com uso de fungicida foliar associado a inoculante na ensilagem, sobre as características químico-fermentativas da silagem. As aplicações do fungicida piraclostrobina + fluxpiroxade foram realizadas nos estádios vegetativo-oito e pendoamento, e as avaliações das plantas ocorreram simultaneamente na colheita (fase de grãos pastosos), quando foi aplicado o inoculante composto por cepas de Lactobacillus buchneri e L. casei para a produção de silagem. O uso de fungicida diminuiu a porcentagem de área foliar afetada por Diplodia macrospora Earle, Cercospora zeae-maydis e Phaeosphaeria maydis. Na colheita, o milho apresentou menor número de folhas secas e maior produtividade de biomassa fresca (66.368 vs. 62.015kg·ha-1) e seca (20.964 vs. 19.485kg·ha-1) com fungicida. O fungicida reduziu teor de LDA de 5,99% para 5,16%, gerando maior ISDMD para planta inteira (43,14 e 62,57%, para 24 e 48 horas, respectivamente). A associação do fungicida com inoculante promoveu maior concentração de ácido acético do que quando cada um foi utilizado isoladamente, e as perdas de matéria seca da silagem com inoculante foram maiores que as da silagem controle (8,88 vs. 12,78%, respectivamente). Fungicida e inoculante utilizados associados proporcionaram silagens com menor teor fibroso. ensilagem químicofermentativas químico fermentativas vegetativooito vegetativo oito pendoamento fase pastosos, pastosos , pastosos) L Earle zeaemaydis zeae maydis 66.368 66368 66 368 (66.36 vs 62.015kg·ha1 62015kgha1 kgha 62.015kg·ha 1 62 015kg ha kg 62.015kg·ha-1 20.964 20964 20 964 (20.96 19.485kg·ha1 19485kgha1 19.485kg·ha 19 485kg 19.485kg·ha-1 599 5 99 5,99 516 16 5,16% 43,14 4314 43 14 (43,1 6257 57 62,57% 2 4 horas respectivamente. respectivamente . respectivamente) isoladamente 8,88 888 8 88 (8,8 1278 12 78 12,78% fibroso 66.36 6636 6 36 (66.3 ha1 62015kgha 62.015kg·ha- 20.96 2096 96 (20.9 19485kgha 19.485kg·ha- 59 9 5,9 51 5,16 43,1 431 (43, 625 62,57 8,8 (8, 127 7 12,78 66.3 663 3 (66. 20.9 209 (20. 5, 5,1 43, (43 62,5 8, (8 12,7 66. (66 20. (20 (4 62, ( 12, (6 (2

Summary: Crop yield estimation based on spectral indices is crucial for decision-making in agricultural activities; however, questions regarding their usefulness persist. The aims of our research were: 1) to relate the radiative properties of forage corn (FC) and biomass production using LANDSAT-8 and SENTINEL-2 images; and 2) to select the best-performing vegetation index (VI) to model FC yield under similar conditions. The study was conducted along the PV-2019 cycle with morphological measurements at different FC growth stages and with destructive random sampling at 72 dds to determine biomass magnitude in the laboratory. Biomass data were then related to reflectance values and VI’s from LANDSAT-8 and SENTINEL-2 to estimate yield through multiple linear regression. Eight VI’s (NDVI, TVI, TTVI, RDVI, RVI, RATIO, SAVI, MSAVI2) were evaluated through cross-evaluations based on key statistics. The results of multiple regression analysis indicated that the best model (R2 = 0.66) was obtained with SENTINEL-2 image data from bands 3 (α3 = 0.54-0.57 µm) and 8 (α8= 0.78-0.90 µm) with highly significant βi estimators (P < 0.05). Moreover, RDVI showed the best performance due to a good spatial relationship between raster digital values and green biomass yield produced with an association of 75.41%, the statistical indicators were R2= 0.75 and CME =17. Yield at 72 dds was predicted both with Multiple Regression Models and VI’s in a range of 10.7 - 57.01 Mg ha-1. In conclusion, SENTINEL-2 outperformed LANDSAT-8 as a free tool for crop assessment and biomass estimation due to its better spatial and temporal resolution.

Resumen: La estimación de cosecha basada en índices espectrales conforma un elemento de decisión importante para quienes participan en la actividad agrícola; sin embargo, muchas interrogantes sobre su utilidad aún persisten. Los objetivos de esta investigación fueron: 1) relacionar propiedades radiativas del maíz forrajero (MF) y producción de biomasa mediante imágenes LANDSAT-8 y SENTINEL-2; y 2) seleccionar el índice de vegetación (IV) con mejor desempeño que permita modelar el rendimiento del MF para condiciones similares. El estudio se realizó en el ciclo PV-2019 con mediciones morfológicas en distintas etapas de crecimiento del MF y mediante muestreos aleatorios destructivos a los 72 dds para determinar magnitud de biomasa en laboratorio; los datos de biomasa se relacionaron con valores de reflectancia e IV de LANDAT-8 y SENTINEL-2 para estimar rendimiento mediante regresión lineal múltiple; ocho IV (NDVI, TVI TTVI, RDVI, RVI, RATIO, SAVI, MSAVI2) se evaluaron mediante evaluaciones cruzadas con base en estadísticos clave. Los resultados del análisis de regresión múltiple indicaron que el mejor modelo (R2 = 0.66) se obtuvo con datos de imágenes SENTINEL-2 a partir de las bandas 3 (α3 = 0.54-0.57 µm) y 8 (α8= 0.78-0.90 µm) con estimadores βi muy significativos (P < 0.05); RDVI presentó el mejor desempeño debido a una buena relación espacial entre los valores digitales ráster y la producción de biomasa verde producida con una asociación del 75.41%; en tanto que los indicadores estadísticos fueron R2= 0.75 y CME=17; con ambos recursos (Modelos de Regresión Múltiple e IV) se pronosticó el rendimiento a los 72 dds en un rango de 10.7 - 57.01 Mg ha-1. La conclusión es que SENTINEL-2 superó a LANDSAT-8 como herramienta libre para la evaluación de cultivos y estimación de biomasa debido a una mejor resolución espacial y temporal.

Abstract Corn is the main grain in the Mexican diet and one of the most important grains worldwide. However, due to its high demand, strategies are required to obtain high yields during its cultivation. In order solve this problem, the effect of high planting densities of the hybrid maize AZ-60 was evaluated. A randomized block design was used in plots to compare maize planting densities in a drip irrigation system and height, stem diameter, fruit values and yield estimation, were evaluated. Three planting densities were selected for the treatments(T): T1) density of 150,000 seeds per hectare; T2) density of 120,000 seeds per hectare; T3) density of 90,000 seeds per hectare. During the harvest period, it was determined that variables such as plant height and stem diameter did not show significant differences. However, it was observed that fruit variables such as number of rows, grains per row and grain weight, the highest values were presented in plant density of 90,000 seeds per hectare. As a result, when estimating the grain yield, differences (p<0.05) were observed between the treatments, the highest being observed in T3 with 7.55 tons per hectare; meanwhile, treatments T2 and T1 were estimated at 5.50 and 5.27 tons per hectare, respectively. It was concluded that the differences observed can be attributed to the increase in intraspecific competition for resources at higher planting densities.

Resumen El maíz es el principal grano en la dieta mexicana y uno de los granos más importantes a nivel mundial. Sin embargo, debido a su alta demanda, se requieren de estrategias para obtener altos rendimientos en su cultivo. Para ayudar a resolver este problema, se evaluó el efecto de altas densidades de siembra del maíz híbrido AZ-60. Se empleó un diseño de bloques al azar en parcelas para comparar densidades de siembra de maíz en un sistema de riego por goteo y evaluar altura, diámetro de tallo, valores en el fruto y estimación del rendimiento. Se seleccionaron tres densidades de siembra para los tratamientos(T): T1) densidad de 150,000 semillas por hectárea; T2) densidad de 120,000 semillas por hectárea; T3) densidad de 90,000 semillas por hectárea. Durante el periodo de cosecha se determinó que variables como la altura de planta y diámetro de tallo no mostraron diferencias significativas. Sin embargo, en variables de la mazorca como número de hileras, granos por hilera y peso de grano, se observó que los mayores valores se presentaron en la densidad de siembra de 90,000 semillas por hectárea. Como resultado, al estimar el rendimiento de grano se observaron diferencias (p<0.05) entre los tratamientos, observándose el mayor en T3 con 7.55 toneladas por hectárea; por su parte los tratamientos T2 y T1 se estimaron 5.50 y 5.27 toneladas por hectárea, respectivamente. Se concluyó, que las diferencias observadas pueden ser atribuidas al aumento de la competencia intraespecífica por recursos a mayores densidades de siembra.

Resumen Introducción. La madurez fisiológica es la acumulación del máximo contenido de materia seca; inciden la línea de leche y la capa negra en la semilla de maíz, como factores morfológicos del grado de maduración. La línea de leche se relaciona con la solidificación del almidón, y la capa negra con el cese de la translocación de sustancias solubles de la planta hacia el grano. El contenido de humedad está relacionado con la madurez fisiológica y a la oportunidad de cosecha asociada con la máxima calidad. Objetivo. Determinar la madurez fisiológica de las semillas por medio de marcadores morfológicos y el contenido de humedad, y su relación con la calidad fisiológica. Materiales y métodos. El estudio se llevó a cabo en el Colegio de Postgraduados, Campus Montecillo en los meses de septiembre y octubre del 2021. Se realizaron muestreos semanales en mazorcas del cultivar experimental (Amarillo x V-54) F6, se tomaron semillas correspondientes a las áreas ápice, media y baja de la mazorca. En función del contenido de humedad se determinó la línea de leche, la capa negra, y la relación de estos factores con la calidad fisiológica (germinación y vigor, envejecimiento acelerado y prueba de frío). Resultados. El contenido de humedad de semillas maduras fue inferior al reportado en la literatura (35 %), también, se logró corroborar a nivel visual la madurez fisiológica por medio de la línea de leche y la capa negra; la germinación se incrementó conforme se avanzó en los muestreos con el menor contenido de humedad y, respecto al vigor, se detectó una mejor repuesta en el envejecimiento acelerado. Conclusiones. En la medida que el contenido de humedad disminuyó, la germinación incrementó. Los marcadores morfológicos permitieron determinar el tiempo en que la semilla de maíz alcanzó la madurez fisiológica, y con ello la máxima calidad.

Abstract Introduction. Physiological maturity is the accumulation of the maximum dry matter content, the milk line and the black layer affect the corn seed, as morphological factors of the degree of maturation. The milk line is related to the solidification of starch, and the black layer with the cessation of the translocation of soluble substances from the plant to the grain. The moisture content is related to the physiological maturity and the harvest opportunity associated with the maximum quality of the product. Objective. Determine seeds physiological maturity, through morphological markers and moisture content, and its physiological quality relationship. Materials and methods. The study was carried out at Colegio de Postgraduados, Campus Montecillo during the months of September-October, 2021. By weekly sampling cobs of experimental cv. (Amarillo × V-54A) F6 genotype, seeds from the apex were taken, middle section and basis. In function by its moisture content, the milk line, black layer, and the relationship of these factor with physiological quality (germination and vigor- accelerated aging and cold tests) were determined. Results. Moisture content was below than referred in literature (35 %), also, physiological maturity was defined visually by milk line and black layer; on the other hand, as sampling were done, there was an increase in seed germination with the less moisture content; what vigor refers, a better response was detected by accelerated aging test. Conclusions. As the moisture content decreased, germination increased. The morphological markers allowed to determine the time in which the maize seed reached the physiological maturity and with it, the maximum quality.

Resumen La plasticidad fenotípica es una propiedad que tiene el cultivo de frijol, como respuesta a estímulos ambientales incluida la fertilización nitrogenada. Esta planta es endémica de México y existen múltiples variantes genéticas, las cuales se adaptan a los diferentes climas y microclimas del país. Respecto al Valle de Tehuacán, Puebla, es considerado el centro de origen de la agricultura en Mesoamérica, porque en él se datan los restos más antiguos de maíz y frijol. Así el objetivo fue: evaluar la plasticidad fenotípica de un frijol de los Valles Centrales de Oaxaca, cuando es sembrado en el Valle de Tehuacán Puebla. La investigación se llevó a cabo bajo condiciones de campo en Tehuacán, Puebla. El germoplasma fue el cultivar. Rocha, que corresponde a un frijol de semilla negra y crecimiento indeterminado. Los tratamientos consistieron en cuatro niveles de nitrógeno 0; 50; 100 y 150 kg ha-1 y cuatro repeticiones, que se evaluaron bajo un diseño de bloques completos al azar. Las variables de respuesta fueron: unidades SPAD, rendimiento de semilla, biomasa seca total, índice de cosecha, unidades calor, evapotranspiración e incidencia de la bacteriosis del frijol. Los resultados indican que el mayor rendimiento agronómico fue en los tratamientos T2 y T1 con: 8.74 y 7.09 g planta-1, mientras que el rendimiento biológico mayor fue 22.15 g planta-1, para el tratamiento T2. La integral térmica fue 1 322 UC, mientras que la evapotranspiración total fue 217.94 mm. Así la mayor incidencia del tizón ocurrió en el testigo con 1.23%. Se concluye, que el cv. Rocha puede ser una alternativa de producción en el Valle de Tehuacán.

Abstract Phenotypic plasticity is a property of bean crops in response to environmental stimuli, including nitrogen fertilization. This plant is endemic to Mexico and there are multiple genetic variants, which adapt to the different climates and microclimates of the country. Regarding the Valley of Tehuacán, Puebla, it is considered the center of origin of agriculture in Mesoamerica, because the oldest remains of corn and beans are dated there. Thus, the objective was: to evaluate the phenotypic plasticity of a bean from the Central Valleys of Oaxaca when sown in the Valley of Tehuacán, Puebla. The research was conducted under field conditions in Tehuacán, Puebla. The germplasm was the cultivar Rocha, which corresponds to a bean with black seeds and indeterminate growth. The treatments consisted of four levels of nitrogen 0; 50; 100 and 150 kg ha-1 and four repetitions, which were evaluated under a randomized complete block design. The response variables were: SPAD units, seed yield, total dry biomass, harvest index, heat units, evapotranspiration and incidence of bean bacterial blight. The results indicate that the highest agronomic yield was in treatments T2 and T1 with 8.74 and 7.09 g plant-1, while the highest biological yield was 22.15 g plant-1, for the treatment T2. The thermal integral was 1 322 HU, while the total evapotranspiration was 217.94 mm. Thus, the highest incidence of blight occurred in the control with 1.23%. It is concluded that the cv. Rocha can be a production alternative in the Valley of Tehuacán.

Abstract The fall armyworm [FAW; Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)], is considered a serious invasive pest that poses a serious threat to world food security. It can completely devastate a whole country's cereal crops. Therefore, the present work is the 1st field trial in Egypt to elucidate some ecological aspects of S. frugiperda on maize plants (Single-Hybrid 168 Yellow Corn cultivar) at Esna district, Luxor Governorate, Egypt, throughout two sequential growing seasons of maize (2021-2022). Three insect parameters were used, i.e., egg masses, number of larvae, and percentage of damaged corn plants. Effects of certain climatic conditions and corn plant ages on S. frugiperda seasonal activity and damaged plants percentage were also estimated. S. frugiperda population initiated to attack maize plants from the 3rd week of June until the harvest in every season. S. frugiperda had two seasonal activity peaks in terms of egg masses numbers and three peaks regarding the larval population density/season. Its damage percentage increased with increasing plant age weekly. The mean of S. frugiperda egg masses were 2.83 ± 0.40 and 2.96 ± 0.45 mass /10 corn plants in 2021 and 2022, respectively. While, the overall mean larval populations were 13.41 ± 0.52 and 13.03 ± 0.46 larvae/10 plants, during the two growing seasons, respectively. Corn plant damage percentages reached 68.54 ± 2.71 and 60.42 ± 2.92% in 2021 and 2022, respectively. The combined effects of both the weather conditions and maize plant ages were highly significant on egg masses, larvae population density, and damage percentage, and varied from one season to another. The mean daily maximum temperature was the most effective variable on egg masses and the larval population. Maize plant age had a clear effect on the damage percentage caused by the larvae in the field during the two years of the study. The dramatic spread of FAW and the consequent damage (that appeared in different countries of America, Africa, and Asia) mean that different management approaches must be sought for the small and large-scale producers by using available technologies for smallholder farmers will eliminate pest damage without access to reach to an economic Injury level. This information may assist the decision maker when planning the S. frugiperda IPM program for maize plants and its surveillance. [FAW Smith (Smith Lepidoptera (Lepidoptera Noctuidae, Noctuidae , Noctuidae)] security countrys country s crops Therefore st S SingleHybrid Single Hybrid 16 cultivar district Governorate 20212022. 20212022 2022 . (2021-2022) used ie i e i.e. estimated rd densityseason density density/season weekly 283 2 83 2.8 040 0 40 0.4 296 96 2.9 045 45 10 /1 202 respectively While 1341 13 41 13.4 052 52 0.5 1303 03 13.0 046 46 larvae10 larvae/1 6854 68 54 68.5 271 71 2.7 6042 60 42 60.4 292 92 2.92 another study America Africa Asia largescale large scale level surveillance Noctuidae) 1 2021202 (2021-2022 i.e 28 8 2. 04 4 0. 29 9 / 20 134 13. 05 5 130 larvae1 larvae/ 685 6 68. 27 7 604 60. 202120 (2021-202 20212 (2021-20 (2021-2 (2021- (2021 (202 (20 (2 (

Resumo A lagarta-do-cartucho [FAW; Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)], é considerada uma séria praga invasora que representa uma séria ameaça à segurança alimentar mundial. Essa espécie pode devastar completamente as plantações de cereais de um país inteiro. Portanto, o presente trabalho é o primeiro ensaio de campo no Egito para elucidar alguns aspectos ecológicos de S. frugiperda em plantas de milho (Single-Hybrid 168 Yellow Corn cultivar) no distrito de Esna, Luxor Governorate, Egito, ao longo de duas estações de crescimento sequencial de milho (2021 a 2022). Três parâmetros de insetos foram utilizados, isto é, massas de ovos, número de larvas e porcentagem de plantas de milho danificadas. Também foram estimados os efeitos de certas condições climáticas e idades das plantas de milho na atividade sazonal de S. frugiperda e na porcentagem de plantas danificadas. A população de S. frugiperda começou a atacar as plantas de milho a partir da terceira semana de junho até a colheita em todas as estações. S. frugiperda apresentou dois picos sazonais de atividade como o número de massas de ovos e três picos em relação à densidade populacional larval/estação. Seu percentual de dano aumentou semanalmente a partir do aumento da idade da planta. A média das massas de ovos de S. frugiperda foi de 2,83 ± 0,40 e 2,96 ± 0,45 massa/10 plantas de milho em 2021 e 2022, respectivamente. Enquanto, as populações larvais médias gerais foram de 13,41 ± 0,52 e 13,03 ± 0,46 larvas/10 plantas, durante as duas estações de crescimento, respectivamente. As porcentagens de danos às plantas de milho atingiram 68,54 ± 2,71 e 60,42 ± 2,92% em 2021 e 2022, respectivamente. Os efeitos combinados das condições climáticas e da idade das plantas de milho foram altamente significativos nas massas de ovos, densidade populacional de larvas e porcentagem de danos, e variaram de uma estação para outra. A temperatura média diária máxima foi a variável mais efetiva sobre as massas de ovos e a população larval. A idade da planta de milho influenciou visivelmente o percentual de dano causado pelas larvas no campo durante os dois anos de estudo. A propagação dramática da LFM e os danos consequentes (que apareceram em diferentes países da América, África e Ásia) significam que devem ser utilizadas diferentes abordagens de gestão para os pequenos e grandes produtores, a partir de tecnologias disponíveis para os pequenos agricultores eliminarem os danos causados pelas pragas sem acesso para chegar a um nível de dano econômico. Essas informações podem auxiliar o tomador de decisão no planejamento do programa MIP de S. frugiperda para plantas de milho e o seu monitoramento. lagartadocartucho lagarta cartucho FAW [FAW Smith (Smith Lepidoptera (Lepidoptera Noctuidae, Noctuidae , Noctuidae)] mundial inteiro Portanto S SingleHybrid Single Hybrid 16 cultivar Esna Governorate (202 2022. 2022 . 2022) utilizados danificadas larvalestação larval larval/estação 283 2 83 2,8 040 0 40 0,4 296 96 2,9 045 45 massa10 massa 10 massa/1 202 respectivamente Enquanto 1341 13 41 13,4 052 52 0,5 1303 03 13,0 046 46 larvas10 larvas/1 6854 68 54 68,5 271 71 2,7 6042 60 42 60,4 292 92 2,92 outra estudo América Ásia produtores econômico monitoramento Noctuidae) 1 (20 28 8 2, 04 4 0, 29 9 massa1 massa/ 20 134 13, 05 5 130 larvas1 larvas/ 685 6 68, 27 7 604 60, (2 (

Resumo O objetivo do presente trabalho é analisar o efeito da expansão da safra de inverno de milho no Brasil sobre a sazonalidade do preço spot dessa commodity em diferentes praças de comercialização no país. Para tal, verificou-se a existência de quebras estruturais nas séries de preços de diferentes regiões (Cascavel-PR, Chapecó-SC, Mogiana-SP, Rio Verde-GO e Triângulo Mineiro-MG) por meio do procedimento endógeno de Bai & Perron (2003). Para cada um dos períodos formados, parâmetros harmônicos foram obtidos com o método de Mínimos Quadrados Ordinários (MQO). Os resultados obtidos permitem concluir que, devido ao crescimento da safra de inverno de milho no Brasil, a variação dos preços desse grão passou a depender em menor proporção do seu padrão sazonal, com exceção de Rio Verde-GO. Além disso, verificou-se uma mudança do comportamento sazonal das cotações nos anos de 2010, observando-se, em geral, preços menores durante a colheita dessa safra (maio a agosto) e maiores na entressafra (janeiro a março). Tais evidências têm o potencial de auxiliar as estratégias de comercialização e gerenciamento do risco de preços dos agentes do setor, bem como podem contribuir para formulação e execução de políticas atreladas à estabilidade da renda dos produtores.

Abstract The purpose of this work is to analyze the impact of the expansion of the Brazilian winter corn crop on spot price seasonality in different regions of the country. We used the Bai & Perron (2003) procedure to identify structural breaks endogenously, considering spot prices for different regions (Cascavel-PR, Chapecó-SC, Mogiana-SP, Rio Verde-GO, and Triângulo Mineiro-MG). Within each regime identified, harmonic parameters were obtained using the Ordinary Least Squares (MQO) method. Results showed that, with the growth of the winter corn crop in Brazil, the price fluctuation started to depend to a lesser extent on its seasonal pattern, except for Rio Verde-GO. In addition, we found evidence that price seasonality changed in 2010s, with lower prices during the harvest of the winter crop (May to August) and higher prices during the planted period (January to March). These findings should offer insights for marketing and risk management strategies and contribute to the design and execution of policies that aim to reduce the variations in the income of producers.

Resumen El ensilado de maíz (Zea mays L.) es el más utilizado en el mundo en dietas de ganado lechero por sus mayores rendimientos de biomasa, palatabilidad, calidad homogénea a la cosecha y facilidad de ensilar por su mayor contenido de azúcar soluble. Se realizó una búsqueda sistemática de estudios para conocer la calidad y el rendimiento de ensilados de maíz en diferentes países con relación al rendimiento de materia seca (t/ha), densidad de población (densidad de plantas/ha), Materia Seca (MS), Proteína Cruda (PC), Fibra Detergente Neutra (FDN), Carbohidratos No Fibrosos (CNF), Materia Orgánica (MO), Digestibilidad de la MS (DMS), Digestibilidad de Fibra Detergente Neutra (DFDN) y producción de leche por hectárea (kg de leche/ha), mediante el programa MILK2006®. Se analizaron 6 clúster (CL, PROC CLUSTER) de ensilado de maíz: CL1: “Almidón”, que incluyó DMS, DFDN, TDN x MS, Mega calorías por kg de MS y kg de leche/tonelada/MS; CL2: “extracto de éter” que incluyó TDN1 x MS, Mcal/kg MS y kg de leche/tonelada MS; CL3: “MS”, conformado solo por DFDN; CL4: “Densidad de plantas” incluyendo el Rendimiento de MS/ha y Producción de leche/ha, CL5: “FDN” y CL6: “PC”. El CL1 se caracterizó por una mayor DMS, DFND, CNF y almidón que permiten una mayor TDN1 x MS y una concentración de energía (Mcal/kg MS) que muestra una mayor producción de leche (kg de leche/tonelada MS/ha). Las características de CL2 con mayor extracto de éter (EE), permiten un mayor TDN1 x MS y concentración de energía (Mcal/kg MS) con mayor producción de leche (kg de leche/tonelada MS/ha) en comparación con otros clústeres. La concentración de MS aumenta en toda la planta por efecto de la madurez, lo que afecta el contenido de almidón y DFDN; el contenido de MS (> 35 g/100 g MS) provoca principalmente una disminución de la DFDN, mientras que en una etapa muy temprana de cosecha de MS (< 25 g/100 g MS) se presenta una baja relación almidón-DFDN.

Abstract Corn sialge (Zea mays L.) is the most widely used in the world in dairy cattle diets because of its higher biomass yields, palatability, homogeneous quality at harvest, and ease of silage due to its higher soluble sugar content. Studies were systematically searched to know the silage corn quality and yield from different countries concerning dry matter yield (t/ha), population density (plant density/ha), quantity of Dry Matter (DM), Crude Protein (CP), Neutral Detergent Fiber (NDF), Non-Fibrous Carbohydrates (NFC), Organic Matter (OM), DM Digestibility (DMD), Neutral Detergent Fiber Digestibility (NDFD), and milk production (kg) per hectare (kg milk/ha) using MILK2006®. Six clusters (CL, PROC CLUSTER) of corn silage were analyzed: CL1: “Starch,” which included DMD, DNDF, TDN1 x DM, Mega calories per kg of DM, and kg of milk/t DM; CL2: “ether extract” which included TDN1 x DM, Mcal/kg DM, and kg of milk/t DM; CL3: “DM,” composed only of DNDF; CL4: “Plant Density,” including Yield of DM/ha and Milk Production/ha; CL5: “NDF,” and CL6: “CP.” In conclusion, CL1 is characterized by a higher DMD, NDFD, CNF, and starch, which allow higher TDN1 x DM and an energy concentration (Mcal/kg DM) with higher milk production (kg milk/ha). CL2 with a higher ether extract (EE) allows higher TDN1 x DM and an energy concentration (Mcal/kg DM) having a higher milk production (kg milk/ha). The DM concentration increases in the whole plant because of maturity, affecting the starch content and NDFD; the DM content (> 35 g/100 g DM) mainly causes a decrease in the NDFD, while in a very early stage of DM harvest (< 25 g/100 g DM) a low ratio of starch:NDFD is present.

Resumen En la agricultura la eficiencia del agua y el equilibrio de oferta y demanda en cultivos son primordial. La falta de conocimientos en proceso de infiltración en riego por gravedad, aumenta en cultivos de alta demanda como maíz, sorgo y frijol. Conocer la retención de humedad en suelos agrícolas es importante, para satisfacer la demanda en la agricultura. Esta investigación tuvo como objetivo estudiar el movimiento hidrodinámico del agua en ocho tratamientos, mesclados de manera homogénea, con aditivos orgánicos y suelo agrícola (franco arcilloso), analizando beneficios en riego por gravedad (Intervalo de riego). La infiltración (F), se analizó con el modelo de Green y Ampt; se evaluaron propiedades físicas directas e indirectas, como son el contenido volumétrico de agua a saturación (θS) y presión capilar frente de humedecimiento (ψf ), curva de tensión de humedad, el segundo parámetro aplicando método de Brooks y Corey (1964), y conductividad hidráulica (Ks). Los resultados son variables relacionando al testigo, mejoradores orgánicos incrementaron un 30 % la retención de humedad y el intervalo de riego incrementó seis días. El incremento en retención de humedad e infiltración acumulada, se obtuvieron con material orgánico (T2) y material orgánico (T7), y obtenidos en residuos en cosecha de maíz.

Abstract In agriculture, water efficiency as well as supply and demand balance in crops are essentials. The lack of knowledge in the infiltration process in gravity irrigation increases in high-demand crops such as corn, sorghum and beans. Knowing the moisture retention in agricultural soils is important to satisfy the demand in agriculture. The purpose of this research was to study the hydrodynamic movement of water in eight treatments, mixed homogeneously, with organic additives and agricultural soil (clay loam), analyzing benefits in gravity irrigation (irrigation interval). Infiltration (F) was analyzed with the Green and Ampt model; direct and indirect physical properties were evaluated, such as the volumetric water content at saturation (θS) and capillary pressure against wetting (ψf), humidity tension curve, the second parameter applying the Brooks and Corey (1964) method, and hydraulic conductivity (Ks). The results are variable in relation to the control, organic improvers increased moisture retention by 30% and the irrigation interval increased by six days. The increase in moisture retention and accumulated infiltration, were obtained with organic material (T2) and organic material (T7), in corn harvest residues.

Abstract The efficiency in the use of water to produce forage groups a series of components related to the crop and the irrigation system, which consists of obtaining a greater production per unit of water consumed. The objective of the work was to know the yield, nutritional quality and water use efficiency (WUE) of the forage corn (Zea mays L.) culture in two irrigation systems under three levels of applied evaporation. The work was established on April 19, 2019, at the La Laguna Experimental Field (CELALA) of the National Institute of Forestry, Agricultural and Livestock Research (INIFAP), located in Matamoros, Coahuila, Mexico. The irrigation systems evaluated were: subsurface drip and surface irrigation. In both systems, the applied sheets corresponded to 100, 75 and 50% of free evaporation of the class ‘A’ evaporimeter pan. The harvest was carried out when the grain was in the R3 milky grain stage. The experimental design used was split plots with four repetitions. The interaction of subsurface drip irrigation system -100% evaporation was higher (p< 0.05) in the variables of height with 2.05 m, green forage yield with 55.08 t and dry forage yield 14.85 t. The combination with the best behavior in WUE in yield with 1.98 kg m-3 and the highest values in WUE in forage quality was surface irrigation system -75% evaporation. There were significant differences between irrigation systems in the quality variables with better results in the surface irrigation system.

Resumen La eficiencia en el uso del agua para la producción de forraje agrupa una serie de componentes relacionados con el cultivo y el sistema de riego que consiste en obtener una mayor producción por unidad de agua consumida. El objetivo del trabajo fue conocer el rendimiento, calidad nutricional y la eficiencia en el uso del agua (EUA) del cultivo del maíz forrajero (Zea mays L.) en dos sistemas de riego bajo tres niveles de evaporación aplicada. El trabajo se estableció el 19 de abril de 2019, en el Campo Experimental La Laguna (CELALA) del Instituto de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) ubicado en Matamoros, Coahuila, México. Los sistemas de riego evaluados fueron: goteo subsuperficial y riego por superficie. En ambos sistemas, las láminas aplicadas correspondieron al 100, 75 y 50% de evaporación libre del tanque evaporímetro clase ‘A’. La cosecha se realizó cuando el grano se encontraba en la etapa de grano lechoso R3. El diseño experimental utilizado fue de parcelas divididas con cuatro repeticiones. La interacción sistema de riego por goteo subsuperficial -100% de evaporación fue superior (p< 0.05) en las variables altura con 2.05 m, rendimiento de forraje verde con 55.08 t y rendimiento de forraje seco 14.85 t. La combinación con mejor comportamiento en EUA en rendimiento con 1.98 kg m-3 y valores más altos en EUA en calidad del forraje, fue el sistema de riego por superficie -75% de evaporación. Se mostraron diferencias significativas entre sistemas de riego en las variables de calidad con mejores resultados en el sistema de riego por superficie.