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

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

ABSTRACT The Indonesian wide range of biogeophysical conditions lead to Genotype×Environment interaction (G×E). Multiple stability analysis methods can provide more comprehensive and reliable information about the G×E. The objective of this research was to determine the yield stability of seven promising maize (Zea mays L.) hybrids (SJI 1, SJI 2, SJI 3, SJI 4, SJI 5, SJI 6, SJI 7) and three control cultivars (Pioneer 36, Bisi 18 and Pertiwi 6) using Francis and Kannenberg, Finlay and Wilkinson, Eberhart and Russel, Shukla and GGE biplot analyses. The hybrids and cultivars were arranged in a randomized complete block design (RCBD) with three replicates in 10 locations in the dry season 2022. The results indicated that hybrid SJI 001 had the highest yield (12.57 t ha-1) and was stable according to the five stability analyses. On the other hand, hybrid SJI 002 (8.36 t ha-1) performed well in unfavourable environments, while hybrid SJI 006 (12.02 t ha-1) and ‘Pertiwi 6’ (11.48 t ha-1) performed well in favourable ones. In addition, GGE biplot analysis revealed that SJI 006 was well adapted to Prambon and ‘Pertiwi 6’ to Bajeng.

RESUMEN El conocimiento del tiempo de drenaje del maíz y del material vegetativo menos susceptible a la inundación son elementos importantes al momento de diseñar la infraestructura de desagüe en los campos agrícolas. Ante esto, este ensayo tuvo como objetivo evaluar el efecto de tres tiempos de saturación hídrica del suelo en tres híbridos de maíz, dentro de la etapa de floración. Se utilizó un diseño de bloques completos al azar, bajo un esquema factorial de 36 unidades experimentales y con distancia de siembra de 0,90 m x 0,25 m. Se emplearon los híbridos DK-7508, EMBLEMA y ADV9313 (niveles del Factor A); los mismos que en etapa plena de floración se inundaron durante 24, 48 y 72 horas, con un tratamiento testigo (0 horas) (niveles del factor B). Se valoró el tamaño y peso de mazorcas, índice grano/tusa, peso de 100 granos y el rendimiento de granos. Se aplicaron modelos de análisis de varianza con esquemas bi-factoriales, se realizó la prueba de Tukey en la comparación de medias para los híbridos, y ajustes de regresión por polinomios ortogonales para verificar tendencias en cuanto a los tiempos de inundación. Se establecieron diferencias significativas (p<0,05) en todas las variables de acuerdo a los tiempos de inundación, con reducciones en el rendimiento de 36,80%, 18,42% y 18,73% para los híbridos DK-7508, EMBLEMA y ADV9313, respectivamente, a las 72 horas de inundación. Predominó la tendencia lineal en las variables y se determinó un tiempo de drenaje entre 29 y 48 horas para una pérdida máxima del 10%, según el híbrido evaluado.

ABSTRACT Knowledge of the drainage time of corn and the vegetative material less susceptible to flooding are important elements when designing drainage infrastructure in agricultural fields. Given this, this trial aimed to evaluate the effect of three times of soil water saturation in three corn hybrids, within the flowering stage. A complete randomized block design was used, under a factorial scheme of 36 experimental units and with a planting distance of 0.90 m x 0.25 m. The hybrids DK-7508, EMBLEMA and ADV9313 were used (Factor A levels); the same ones that in the full flowering stage were flooded for 24, 48 and 72 hours, also evaluating a control treatment (0 hours) (factor B levels). The size and weight of ears, grain/cob index, weight of 100 grains and yield were evaluated. Analysis of variance models with bi-factor schemes, Tukey test in the comparison of means for the hybrids and regression adjustments by orthogonal polynomials were applied to verify trends in terms of flooding times. Significant differences (p<0.05) were established in all variables according to flooding times, with reductions in yield of 36.80%, 18.42% and 18.73% for the DK-7508 hybrids. EMBLEMA and ADV9313, respectively, at 72 hours of flooding. The linear trend predominated in the variables and a drainage time was determined between 29 and 48 hours for a maximum loss of 10%, depending on the hybrid evaluated.

Abstract The term teosinte applies to a group of species and subspecies of the genus Zea, including the wild ancestor of maize. In 2014, its presence was reported in corn fields in Aragon and Catalonia, where it can cause significant reductions in the harvest. Different control measures have been put in place to contain its advance, including the exceptional authorization of the cultivation of corn tolerant to the herbicide cycloxydim (acetyl CoA carboxylase enzyme inhibitor) in infested areas. The relationship between maize and teosinte allows hybridization and the possibility of gene flow from maize to the wild plant. Introgression of herbicide resistance genes from maize to teosinte has recently been reported in France where cycloxydim-tolerant maize is authorized for cultivation. In this study, the hybridization rate between a cycloxydim tolerant maize cultivar and teosinte introduced in Spain was determined during three years and the phenology during the vegetative and reproductive phase of hybrids and parents was monitored. For this purpose, free-flowering crosses between teosinte as female parent and maize as male parent were carried out under outside uncontrolled environmental conditions. Hybrid identification was carried out by spraying with cycloxydim (200 g. m.a. ha-1). Despite the flowering overlap between teosinte and maize, hybrids were obtained in only one of the three years at a rate of 3.4%.

Resumen El término teosinte se aplica a un grupo de especies y subespecies del género Zea, entre las que se encuentra el ancestro silvestre del maíz. En 2014 se notificó su presencia en campos de maíz de Aragón y Cataluña, donde ocasiona reducciones importantes en la cosecha. Se han puesto en marcha diferentes medidas de control para contener su avance, entre ellas la autorización excepcional del cultivo de maíz tolerante al herbicida cicloxidim (inhibidor del enzima acetil CoA carboxilasa) en las zonas infestadas. La relación entre el maíz y el teosinte permite su hibridación y la posibilidad de un flujo de genes del maíz a la planta silvestre. La introgresión de genes de resistencia a herbicidas del maíz a teosinte ha sido recientemente citada en Francia donde está autorizado el cultivo de maíz tolerante a cicloxidim. En este estudio se ha determinado durante dos años la tasa de hibridación entre un cultivar de maíz tolerante a cicloxidim y el teosinte introducido en España y se ha realizado un seguimiento de la fenología vegetativa y reproductiva de híbridos y parentales durante un año. Para ello, se han llevado a cabo cruzamientos de floración libre entre teosinte como parental femenino y maíz como parental masculino en el exterior en condiciones ambientales no controladas. La identificación de los híbridos se realizó mediante pulverización con cicloxidim (200 g. m.a. ha-1). A pesar del solapamiento de la floración entre el teosinte y el maíz, únicamente se obtuvieron híbridos en uno de los años en un porcentaje del 3,4%.

Abstract The fall armyworm [FAW; Spodoptera frugiperda (J.E Smith, 1797)] is an invasive and polyphagous insect that infests cereal crops, causing economic losses, and may be led to pose a threat to future the global maize crop in the future. Field trials were conducted to study the negative impacts of S. frugiperda on vegetative growth measurements, yield, and the components of the maize cultivar (Single-Hybrid 168 Yellow) in Luxor Governorate, Egypt. S. frugiperda larvae infestation to maize plants was observed in the 3rd week of June and so continued till the harvest in both 2021 and 2022 seasons. S. frugiperda had three peaks of the seasonal activity/season in the untreated (pesticide-free, control) and in the treated main plots by pesticides. Maize vegetative growth attributes (averages of plant height, stem diameter, and the number of green leaves per plant) displayed higher rates of the treated maize plants by insecticides against S. frugiperda. Maize grain, straw, and biological yield (kg/ha) were decreased in the untreated maize plants (insecticides free) than in the treated by insecticides. Concerning maize yield components, the treated plants were to outperform in the average length of a plant stem (cm), stem diameter (cm), and weight of cob (g), as well as, number of rows/cob, number of grains/ cob, number of grains/cob, maize cob grain weight (g) and weight of 1000-grains (g)], in comparison with the untreated plants. Also, the FAW infestation to untreated maize plants was decreased well in all calculated maize growth attributes, i.e., grain yield, and components. Regarding the relationship between variations in a given variable and the changes in S. frugiperda larvae numbers and plant damage percentage, the simple correlation and regression coefficient revealed a highly significant negative relationship in all the parameters tested. The obtained information may help farmers and decision-makers in the management of FAW populations based on an effective plan related to control measures that should be implemented. [FAW J.E JE J E Smith 1797 1797) crops losses S measurements SingleHybrid Single Hybrid 16 Yellow Governorate Egypt rd 202 seasons activityseason activity season pesticidefree, pesticidefree pesticide free, free (pesticide-free pesticides averages height straw kg/ha kgha kg ha (kg/ha cm, cm , (cm) g, g rowscob rows rows/cob grains grainscob grains/cob (g 1000grains 1000 (g)] Also ie i e i.e. percentage tested decisionmakers decision makers implemented 179 1 20 (cm 100 i.e 17 2 10

Resumo A lagarta-do-cartucho [FAW; Spodoptera frugiperda (J.E Smith, 1797)] é um inseto invasor e polífago que infesta culturas de cereais, responsável por perdas econômicas, representando uma ameaça para a cultura mundial de milho no futuro. Ensaios de campo foram conduzidos para estudar os impactos negativos de S. frugiperda nas medidas de crescimento vegetativo, rendimento e os componentes da cultivar de milho (Single-Hybrid 168 Yellow) na província de Luxor, Egito. A infestação de larvas de S. frugiperda nas plantas de milho foi observada na terceira semana de junho e prosseguiu até a colheita nas temporadas de 2021 e 2022. A espécie S. frugiperda teve 3 picos da atividade sazonal nas parcelas não tratadas (sem agrotóxicos e controle) e nas tratadas com agrotóxicos. Os atributos de crescimento vegetativo do milho (médias de altura da planta, diâmetro do caule e número de folhas verdes por planta) apresentaram maiores taxas das plantas de milho tratadas com inseticidas contra S. frugiperda. O grão de milho, a palha e o rendimento biológico (kg/ha) diminuíram nas plantas de milho não tratadas (sem inseticidas) do que nas plantas tratadas com inseticidas. Com relação aos componentes de rendimento do milho, as plantas tratadas tiveram desempenho superior no comprimento médio do caule da planta (cm), diâmetro do caule (cm) e peso da espiga (g), bem como, número de fileiras/espiga, número de grãos/espiga, número de grãos/espiga, peso de grãos de espiga de milho (g) e peso de 1000 grãos (g), em comparação com as plantas não tratadas. Além disso, a infestação de LFM em plantas de milho não tratadas diminuiu consideravelmente em todos os atributos de crescimento do milho calculados, ou seja, rendimento de grãos e componentes. Quanto à relação entre as variações de uma determinada variável e as mudanças no número de larvas de S. frugiperda e na porcentagem de danos às plantas, a correlação simples e o coeficiente de regressão revelaram uma relação negativa e altamente significativa em todos os parâmetros testados. A informação obtida pode ajudar os agricultores e gestores das populações da LFM com base num plano eficaz relacionado às medidas de controle que devem ser implementadas. lagartadocartucho lagarta cartucho FAW [FAW J.E JE J E Smith 1797 1797) cereais econômicas futuro S SingleHybrid Single Hybrid 16 Yellow Luxor Egito 202 2022 sem médias kg/ha kgha kg ha (kg/ha cm, cm , (cm g, g como fileirasespiga fileiras fileiras/espiga grãosespiga grãos/espiga (g 100 disso calculados seja testados implementadas 179 1 20 10 17 2

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,

Resumo Hoje, o milho doce é considerado uma hortaliça importante devido ao seu alto teor de açúcar e baixo teor de amido. A análise de agrupamento e a análise de variância mostraram que os híbridos apresentaram variações nos índices de produtividade. Os híbridos GB, DE e GS tiveram desempenho semelhante nos índices. Híbrido SE que apresenta desempenho significativo sobre a zeaxantina. Biplot mostrou que frutose, glicose, sacarose e potássio apresentaram valor de estabilidade em híbridos. Todos os híbridos tiveram o melhor desempenho nos fatores frutose, glicose, sacarose e potássio. O fator biplot correlacionou-se positivamente com os índices de rendimento, incluindo cálcio, ferro, zinco, magnésio, α-caroteno, 9Z-β-caroteno, fósforo e β-caroteno. Por outro lado, há correlação positiva com frutose, glicose, potássio, luteína, sacarose, β-criptoxantina e zeaxantina. Assim, para avaliar ou aumentar a luteína e a zeaxantina, outros parâmetros como o teor de açúcares (frutose, glicose e sacarose) são fatores importantes e atuam em conjunto. A análise fatorial e o biplot mostraram que o híbrido ME apresentou desempenho máximo no primeiro fator de índices de produtividade. Além disso, o segundo fator de índices de produtividade teve um efeito máximo nos híbridos de NO. Os híbridos SE tiveram desempenho máximo em zeaxantina e o híbrido GS teve desempenho máximo em zinco, fósforo e ferro. A matéria seca apresentou estabilidade no híbrido DB.

Abstract Today, sweet corn is considered an important vegetable due to its high sugar content and low starch content. Cluster analysis and variance analysis showed that hybrids had variations in yield indices. GB, DE and GS hybrids had similar performance on indices. SE hybrid that has significant performance on zeaxanthin. Biplot showed that fructose, glucose, sucrose and potassium had stability value on hybrids. All the hybrids had the best performance on fructose, glucose, sucrose and potassium factors. Factor biplot positively correlated with yield indices, including calcium, iron, zinc, magnesium, α-Carotene, 9Z-β-Carotene, phosphorus, and β-carotene. On the other hand, there is a positive correlation with fructose, glucose, potassium, lutein, sucrose, β-Cryptoxanthin, and zeaxanthin. So, to evaluate or increase lutein and zeaxanthin, the other parameters like sugar content (fructose, glucose, and sucrose) are important factors and have an effect together. Factor analysis and biplot showed that ME hybrid had a maximum performance on the first factor of yield indices. Also, the second factor of yield indices had a maxi-mum effect on NO hybrids. SE hybrids had maximum performance in zeaxanthin and GS hybrid had maximum performance in zinc, phosphorus, and iron. The dry matter had stability on DB hybrid.

ABSTRACT The objective of this work was to evaluate the potential of vegetation indices (VIs), obtained using aerial images from an unmanned aerial vehicle (UAV), for assessing water status of maize hybrids subjected to different water regimes under the soil and climate conditions of Teresina, Piauí, Brazil. Evaluations were carried out considering the application of five water regimes (WR) based on the crop evapotranspiration (ETc) (40%, 60%, 80%, 100%, and 120% of ETc) for three maize hybrids: BRS 3046 (conventional triple hybrid), BRS 2022 (conventional double hybrid), Status VIP3 (transgenic simple hybrid). A randomized block experimental design with four replications was used, in a 5×3 split-plot arrangement, consisting of WRs in the plots and maize hybrids in the subplots. A UAV was used for acquiring multispectral images. Eighteen VIs were evaluated and correlated with stomatal conductance (gs), leaf relative water content (RWC), and grain yield (GY). The VIs TCARI -RE and NDVI presented correlation with gs, whereas MNGRD and GCI presented correlation with RWC; therefore, they were considered promising for assessing the water status of maize plants. NDVI and WDRVI presented correlations with GY. Maps of NDVI, MNGRV, and WDRVI showed spatial correlation with gs, RWC, and GY measurements, respectively, in response to the applied WRs, denoting potential for assessing the water status of maize plants using aerial images from UAV. VIs, , (VIs) UAV, (UAV) Teresina Piauí Brazil WR (WR ETc (ETc 40%, 40 (40% 60 60% 80 80% 100 100% 120 304 conventional hybrid, hybrid hybrid) 202 VIP transgenic hybrid. . 53 5 3 5× splitplot split plot arrangement subplots gs (gs) RWC (RWC) (GY) RE therefore MNGRV measurements respectively (VIs (UAV 40% 4 (40 6 8 10 12 30 20 (gs (RWC (GY (4 1 2 (

RESUMO Objetivou-se avaliar a capacidade de índices de vegetação (IV), obtidos de imagens aéreas por aeronave remotamente pilotada (ARP), em detectar o estado hídrico de híbridos de milho submetidos a diferentes regimes hídricos, nas condições de solo e clima de Teresina, Piauí, Brasil. Avaliou-se a aplicação de cinco regimes hídricos (RHs) com base na evapotranspiração da cultura (ETc) (40%, 60%, 80%, 100% e 120% da ETc) em três híbridos de milho: BRS 3046 (híbrido triplo convencional); BRS 2022 (híbrido duplo convencional); e Status VIP3(híbrido simples transgênico). O delineamento experimental foi o de blocos ao acaso, parcelas subdivididas, sendo as parcelas os RHs e as subparcelas os híbridos, com quatro repetições. Utilizou-se uma ARP para a aquisição das imagens multiespectrais. Avaliaram-se 18 índices de vegetação, os quais foram correlacionados com medidas de condutância estomática (gs), conteúdo relativo de água na folha (CRA) e produtividade de grãos (PG). Os IVs TCARI-RE e NDVI apresentaram correlação com gs e os IVs MNGRD e GCI foram correlacionados com o CRA e, portanto, são considerados promissores na detecção do estado hídrico do milho. Os IVs NDVI e WDRVI apresentaram correlações com a PG. Os mapas de NDVI, MNGRV e WDRVI mostraram correlação espacial com as medidas de gs, CRA e PG, respectivamente em resposta aos RHs, indicando aplicação potencial na detecção do estado hídrico do milho por meio de imagens aéreas obtidas por ARPs. Objetivouse Objetivou se IV, IV , (IV) ARP, (ARP) Teresina Piauí Brasil Avaliouse Avaliou (RHs ETc (ETc 40%, 40 (40% 60 60% 80 80% 100 120 304 híbrido convencional convencional) 202 VIP3híbrido VIPhíbrido VIP3 VIP transgênico. transgênico . transgênico) acaso subdivididas repetições Utilizouse Utilizou multiespectrais Avaliaramse Avaliaram 1 (gs) (CRA PG (PG) TCARIRE TCARI RE portanto ARPs (IV (ARP 40% 4 (40 6 8 10 12 30 20 (gs (PG (4 3 2 (

ABSTRACT. Popcorn (Zea mays L. everta) is a specialty crop with a higher aggregate economic value than that of common maize. In Brazil, national literature is still incipient and contradictory in terms of plant population management and water requirements. Furthermore, the interaction between these factors has not been reported, despite the increasing cultivation of popcorn. The objective of this trial was to determine whether agricultural traits and popping expansion from hybrid IAC 125 could be affected by plant density and levels of irrigation water, in addition to determining the significance level of the interaction between both factors. We investigated five plant populations (40,000, 55,000, 70,000, 85,000, and 100,000 plants ha-1) and five different levels of water depth in 2014/2015 [574.86 (without supplementary irrigation), 609.86, 644.86, 679.86 (control), and 714.86 mm] and 2015/2016 [857.4 (without supplementary irrigation), 867.26, 886.60, 916.78 (control), and 959.81 mm] using a complete block design with split-plot, comprising a main plot (for plant populations) and subplot (for water depth), with six replicates for each set. We found increasing linear effects from grain yield under population density and levels of water depth, but this interaction was not significant. Moreover, the popping expansion for the main effects and the interaction between plant populations and water depth, were not significant. ABSTRACT Zea L everta maize Brazil requirements Furthermore reported popcorn 12 40,000, 40000 40 000 (40,000 55000 55 55,000 70000 70 70,000 85000 85 85,000 100000 100 100,00 ha1 ha 1 ha-1 20142015 2014 2015 2014/201 574.86 57486 574 86 [574.8 without irrigation, , irrigation) 60986 609 609.86 64486 644 644.86 67986 679 679.8 control, control (control) 71486 714 714.8 mm 20152016 2016 2015/201 857.4 8574 857 4 [857. 86726 867 26 867.26 88660 886 60 886.60 91678 916 78 916.7 95981 959 81 959.8 splitplot, splitplot split plot, split-plot depth) set significant Moreover 40,000 4000 00 (40,00 5500 5 55,00 7000 7 70,00 8500 8 85,00 10000 10 100,0 ha- 2014201 201 2014/20 574.8 5748 57 [574. 6098 609.8 6448 64 644.8 6798 67 679. (control 7148 71 714. 2015201 2015/20 857. [857 8672 2 867.2 8866 88 6 886.6 9167 91 916. 9598 95 959. 40,00 400 0 (40,0 550 55,0 700 70,0 850 85,0 1000 100, 201420 20 2014/2 574. [574 609. 644. 201520 2015/2 [85 867. 886. 9 40,0 (40, 55, 70, 85, 20142 2014/ [57 20152 2015/ [8 40, (40 [5 [ (4 (

ABSTRACT: Faster phenotyping tools are crucial for field progeny selection. We conducted research comparing two water deficit simulation methods on contrasting cultivars for water deficit tolerance. In a first step, we conducted two experiments: one for seed germination in sand at 10% and 70% water retention capacity, being analyzed seedling emergence and growth; other for seed germination in stress simulation by moistening the germination paper with PEG solution at -0.6 MPa, being analyzed seed germination. These experiments were used to distinguish characteristics of two maize lineages with different response to drought, being 57 - sensitive and 91 - tolerant. After that, we produced hybrid progenies from these lines at generations F1, F2, and F2:3 and applied the stress simulation by moistening the germination paper with -0.6 MPa of PEG solution. The seedling size was analyzed trough image analysis by the GroundEye® system. We could distinguish both lines and its hybrids through the stress simulation and image analysis. The results indicate that maize cultivars can be phenotyped for water deficit tolerance either 5 days postsowing through stress simulation or via image analysis of root length from seedlings germinated under -0.6 MPa. This method provides faster, more accurate, and more cost-effective methods for assessing water deficit tolerance in maize cultivars. ABSTRACT selection step 10 70 capacity growth 0.6 06 0 6 -0. drought 9 tolerant F1 F F2 F23 3 F2: GroundEye system faster accurate costeffective cost effective 1 7 0. -0

Resumo: Ferramentas rápidas de fenotipagem são cruciais para a seleção de progênies em programas de melhoramento genético. Esta pesquisa foi conduzida com o objetivo de avaliar a possibilidade de uso da simulação de estresse em laboratório como forma de distinguir fenótipos de milho quanto à tolerância à seca. Foram conduzidos inicialmente dois experimentos: um em que avaliou-se a emergência de plântulas e seu crescimento em areia sob diferentes capacidades de campo; e um segundo com o uso de solução de PEG a -0.6 Mpa para umedecer o papel de germinação. Estes experimentos foram usados para distinguir características de duas linhagens contrastantes quanto à tolerância à seca: linhagem 57 - sensível e 91 - tolerante. No próximo experimento, foram produzidas sementes hibridas a partir do cruzamento de ambas as linhagens nas gerações F1; F2 e F2:3 as quais foram colocadas para germinar em papel umedecido com solução de PEG a -0.6 MPa com posterior avaliação do crescimento das sementes através da análise de imagens com o sistema GroundEye®. Pelos resultados dessa pesquisa foi possível distinguir tanto as características das linhagens parentais quanto as progênies hibridas quanto à tolerância à seca. Neste sentido, pode-se concluir que a simulação do estresse associada à análise de imagens pode ser uma ferramenta útil para fenotipagem de milho. Resumo genético seca avaliouse avaliou se campo 0.6 06 0 6 -0. germinação 5 9 tolerante experimento F1 F F23 3 F2: GroundEye GroundEye® sentido podese 0. -0

ABSTRACT Brazil boasts a vast variety of environmental conditions conducive to maize cultivation. Given the various maize hybrids available in the Brazilian market, properly selecting and positioning different genetic materials are critical for successful grain production. Thus, this study aimed to determine the adaptability and stability of different maize hybrids, comparing the Eberhart and Russell and AMMI models, to guide the positioning of these maize hybrids in subtropical regions. A randomized block experimental design with six hybrids and three replicates was used. The experimental environments were defined by combinations of factors such as location, sowing time, fungicide management and irrigation, resulting in 12 distinct environments. Notably, the two models largely agree. For instance, the AG 9025 PRO3 hybrid showed a high yield during early sowing under favorable conditions, whereas the AS 1730 PRO3 and DKB 230 PRO3 hybrids had good yields even under unfavorable conditions. The main limitation of the Eberhart and Russell model is its limited ability to interpret stability, classifying hybrids only as having high or low predictability, limiting the detailed interpretation of stability. Conversely, the AMMI model offers a more detailed analysis of stability, allowing the interpretation of hybrid stability within a broader set and presenting information graphically, which facilitates understanding and enables a more comprehensive and accurate analysis for the appropriate positioning of maize hybrids. cultivation market production Thus regions used location time irrigation 1 Notably agree instance 902 PRO 173 23 predictability Conversely graphically 90 17 2 9

RESUMO O Brasil apresenta uma diversidade de condições ambientais propícias para o cultivo de milho. Considerando a quantidade de híbridos de milho disponíveis no mercado brasileiro, a seleção e o posicionamento precisos dos materiais genéticos são fundamentais para o êxito na produção. Este estudo tem como objetivo determinar a adaptabilidade e estabilidade de diferentes híbridos de milho, comparando as metodologias de Eberhart e Russell e AMMI, para orientar o posicionamento desses híbridos em regiões subtropicais. Utilizou-se um delineamento experimental em blocos ao acaso com seis híbridos e três repetições. Os ambientes experimentais foram definidos por combinações de fatores como local, época de semeadura, manejo com fungicida e irrigação, resultando em 12 ambientes distintos. Os resultados demonstram que as metodologias avaliadas corroboram parcialmente entre si. O híbrido AG 9025 PRO3 mostrou-se altamente produtivo em semeaduras precoces em ambientes favoráveis. Em contraste, os híbridos AS 1730 PRO3 e DKB 230 PRO3 apresentaram bom desempenho produtivo mesmo em condições desfavoráveis. A principal limitação do modelo Eberhart e Russell é a sua capacidade limitada de interpretar a estabilidade, classificando os híbridos apenas como de alta ou baixa previsibilidade, o que limita a interpretação detalhada da estabilidade. Por outro lado, o modelo AMMI oferece uma análise mais detalhada da estabilidade, permitindo interpretar a estabilidade dos híbridos dentro de um conjunto mais amplo e apresentar informações de forma gráfica, o que facilita a compreensão e possibilita uma análise mais abrangente e precisa para o posicionamento adequado de híbridos de milho. brasileiro produção subtropicais Utilizouse Utilizou se repetições local semeadura irrigação 1 distintos si 902 PRO mostrouse mostrou favoráveis contraste 173 23 desfavoráveis previsibilidade lado gráfica 90 17 2 9

Abstract Maize is considered one of the most important cereal fodder crops. Many studies on morphological diversity in fodder maize have been helpful in obtaining good heterotic hybrids. The current study focused on analysing diversity of 28 fodder maize inbreds with 30 SSR markers, which revealed total of 110 alleles; and their polymorphic information content (PIC) values ranged from 0.064 to 0.745. Population structure analysis revealed four subpopulation groups with the ΔK value of 132.70. Clustering based on the pairwise dissimilarity coefficient grouped the genotypes into two major and four sub-clusters. The high dissimilarity (0.777) observed between DM 84 and UMI 1221 indicated that these two were highly divergent. Principal coordinate analysis also showed diverse nature of inbreds and corroborated the clustering pattern. Parental diversity and their heterosis performance revealed that parents with average or narrow divergence could be useful in obtaining hybrids with medium/early flowering and moderate/high crude protein content. crops 2 3 markers 11 alleles PIC (PIC 0064 0 064 0.06 0745 745 0.745 13270 132 70 132.70 subclusters. subclusters sub clusters. clusters sub-clusters 0.777 0777 777 (0.777 8 122 divergent pattern mediumearly medium early moderatehigh moderate 1 006 06 0.0 074 74 0.74 1327 13 7 132.7 0.77 077 77 (0.77 12 00 0. 07 0.7 132. (0.7 (0. (0 (

Summary: Food insufficiency in corn and water and fertilizer crisis worldwide demand efficiency in the use of resources, increasing or conserving production. Thus, the objective of this research is to explore the response of four white maize hybrids released for valles Altos in two environments considering two population densities, two doses of fertilization and an unfertilized control group. Hybrids were evaluated in a factorial arrangement in Cuautitlan (FESC-UNAM) and Texcoco (CEVAMEX), Mexico State, at two planting densities (D1 = 75,000; D2 = 90,000 plants ha-1) with three fertilization treatments (F1 = 160-80-00, F2 = 120-40-00, F3 = 00-00-00). The completely randomized block design experiment was made up of the treatments and the combination of the factors 2×4×2×3 established in three repetitions. The means were compared with Tukey’s test (P < 0.05). In FESC-UNAM with less total water, the result of grain yield and water productivity was 5.96 Mg ha-1 and 1.29 kg m-3 in CEVAMEX 4.76 Mg ha-1 and 0.5 kg m-3; the Atziri Puma hybrid stood out with 6.52 Mg ha-1 and 1.09 kg m-3. No significant effect of planting density was observed and D1 resulted with 5.32 Mg ha-1 and 0.9 kg m-3 versus D2 with 5.40 Mg ha-1 and 0.9 kg m-3. In fertilization F1 was statistically higher with 5.64 Mg ha-1 and 0.94 kg m-3. Nevertheless, no difference was observed between F2 (5.24 Mg ha-1 and 0.88 kg m-3) and the control F3 (5.19 Mg ha-1 and 0.87 kg m-3), which showed the interaction of the environments with hybrids, of which Atziri Puma stood out at FESC-UNAM (7.3 Mg ha-1 and 1.58 kg m-3). The FESC-UNAM site has productive potential under rainfed conditions with the Puma and INIFAP hybrids.

Resumen: La insuficiencia alimentaria en maíz, la crisis de agua y fertilizantes a nivel mundial, demandan incrementar la eficiencia en el uso de recursos incrementando o conservando la producción. El objetivo del trabajo fue definir la respuesta de cuatro híbridos de maíz blanco (Tlaoli Puma, Atziri Puma, H-49 AE y H-47 AE) en dos ambientes con dos densidades de población y dos dosis de fertilización y testigo sin fertilizar. Como arreglo factorial, en los ambientes Cuautitlán (FESC-UNAM) y Texcoco (CEVAMEX), Estado de México, se evaluaron los híbridos con dos densidades de siembra (D1=75 000; D2=90 000 plantas ha-1) y tres tratamientos de fertilización (F1=160-80-00, F2=120-40-00, F3=00-00-00). El experimento en bloques completos al azar se conformó con los tratamientos y la combinación de los factores 2×4×2×3 establecidos en tres repeticiones. Las medias se compararon con el método Tukey (P < 0.05). Para el rendimiento de grano y productividad del agua, en la FESC-UNAM con menor agua total, resultaron de 5.96 Mg ha-1 y 1.29 kg m-3 en CEVAMEX 4.76 Mg ha-1 y 0.5 kg m-3; el híbrido Atziri Puma sobresalió con 6.52 Mg ha-1 y 1.09 kg m-3. No se observó efecto significativo de la densidad de siembra y D1 resultó con 5.32 Mg ha-1 y 0.9 kg m-3 contra D2 con 5.4 Mg ha-1 y 0.9 kg m-3. En la fertilización, F1 fue superior estadísticamente con 5.64 Mg ha-1 y 0.94 kg m-3, pero no hubo diferencia entre F2 (5.24 Mg ha-1 y 0.88 kg m-3) y el control F3 (5.19 Mg ha-1 y 0.87 kg m-3). Se presentó interacción de los ambientes con los híbridos y destacó el híbrido Atziri Puma en la FESC-UNAM (7.3 Mg ha-1 y 1.58 kg m-3). El sitio FESC-UNAM tiene potencial productivo en condiciones de temporal con los híbridos Puma e INIFAP.

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 Para incrementar la eficiencia en la producción de semillas híbridas en maíz se necesitan altos rendimientos con un correlativo bajo costo de producción. Esto requiere una expansión de los conocimientos básicos de la herencia de caracteres que posibiliten desarrollar nuevas técnicas de mejoramiento sobre materiales experimentales de textura dura (flint). Los sistemas de letales balanceados permiten estudiar la contribución relativa de distintos segmentos heteróticos en el vigor híbrido dado que permiten lograr la heterocigosis cuasipermanente de una porción del genomio, mientras el resto del genoma se vuelve homocigota por autofecundaciones sucesivas. Estos sistemas pueden ser transferidos a líneas endocriadas para incrementar el rendimiento del grano y el tamaño de la panoja para aumentar la producción de polen. El objetivo de este trabajo fue incorporar un segmento heterótico de una línea regulada por un sistema de letales balanceados (BLS14), mediante cruzamiento y retrocruza, a líneas S5 derivadas de dos híbridos comerciales, ACA 2000 y Cóndor, de pedigree cerrado, con textura dura (flint), con la finalidad de aumentar el rendimiento en grano o el tamaño de la panoja para la producción de polen. Los análisis de variancia (ANOVA) y de componentes principales (ACP) mostraron un incremento significativo en el rendimiento del grano y el tamaño de la panoja de las líneas S5 de ambos híbridos comerciales, portando cada una de ellas el segmento heterótico proveniente de la línea BLS14.

ABSTRACT In order to increase the efficiency of maize hybrid seed production it is necessary to achieve a high grain yield to reduce production costs. This goal requires an expansion of the basic knowledge of the inheritance of characters in order to develop new breeding techniques to improve experimental materials with hard endosperm (flint). The balanced lethal system allows to study the relative contribution of different chromosome segments to hybrid vigour due to the heterozygosity of certain chromosome segments while the rest of the genome becomes homocygotic through continuous selfing. In this way, these segments can be transferred to inbred lines in order to increase grain yield or tassel size (to increase pollen production). The goal of this study was to transfer a heterotic segment by using a balanced lethal system regulated line (BLS14), through crosses and backcrosses, to S5 flint lines derived from two commercial hybrids, ACA 2000 and Cóndor with closed pedigree, with the objective of increase grain yield or tassel size for pollen production. The analysis of variance (ANOVA) and principal components analysis (PCA) showed a significant improvement in grain yield and tassel size in the S5 flint lines of both commercial hybrids, carrying the heterotic segment of the BLS14 line.