Abstract Background: Agricultural management modifies the microclimate in the cultivated area, improving the physiology and productivity of plants. Questions: How does the microclimate, physiology and productivity of maize vary in a monoculture (M) and a milpa (polyculture, MFC) in shallow and deep soils of Yucatan? Study species: Zea mays L. Study site and date: Yucatán, Mexico; 2022 Methods: Air and soil temperature, water vapor pressure deficit, dew formation and volumetric soil water content (CVA); CO2 assimilation (A), transpiration (E), stomatal conductance (gs), water use efficiency, chlorophyll content (CC), quantum efficiency, electron transport rate and non-photochemical dissipation in maize plants were measured at 40 and 75 days after planting, in milpas and monocultures in Peto (shallow soil with high stoniness) and Mama (deeper soils with low stoniness), Yucatán. Results: The soil temperature was up to 5 °C higher in Peto and 2 °C in Mama in M compared to MFC, where soil water was also up to 22 % higher than in M. Maize plants in Mama showed higher A and E than those of Peto; the plants in MFC in Peto had higher A, E and gs than those of M; the opposite was observed in Mama. The CRA and CC were higher in MFC plants in Peto. Conclusions: The microclimatic modification associated with the polyculture, and its effect on maize was related to the soil: the Milpa was more productive on stony soils and monoculture in deep soils. The CVA was higher in MFC.

Resumen Antecedentes: El manejo agrícola modifica el microclima en el área de cultivo, afectando la fisiología y productividad de las plantas. Preguntas: ¿Cómo varía el microclima, fisiología y productividad del maíz en un monocultivo (M) y una milpa (policultivo, MFC) en suelos profundo y superficial de Yucatán? Especie de estudio: Zea mays L. Sitio de estudio: Yucatán, México; 2022 Métodos: Se midió temperatura del aire y suelo, déficit de presión de vapor, formación de rocío y contenido volumétrico de agua en suelo (CVA); asimilación de CO2 (A), transpiración (E), conductancia estomática (gs), eficiencia en el uso del agua, contenido de clorofila (CC), eficiencia cuántica, tasa de transporte de electrones y disipación no fotoquímica en plantas de maíz a 40 y 75 días después de la siembra, en milpas y monocultivos en Peto (suelo superficial, alta pedregosidad) y Mama (suelo más profundo, baja pedregosidad), Yucatán. Resultados: La temperatura del suelo fue hasta 5 °C mayor en Peto y 2 °C en Mama en M respecto a MFC, que registró hasta 22 % mayor CVA que M. El maíz en Mama presentó mayor A y E que en Peto; las plantas en MFC en Peto tuvieron mayor A, E y gs que las de M; en Mama fue lo contrario. El CRA y CC fue mayor en plantas de MFC en Peto. Conclusiones: La modificación microclimática y su efecto sobre el maíz dependió del suelo: MFC fue más productiva en suelos superficiales, mientras M en suelos profundos. El CVA fue mayor en MFC.

ABSTRACT: Pineapple is a tropical fruit with high demand by the fruit market in Brazil. Fruits of the cultivar ´Turiaçu` stans out in local consumer markets due to its excellent quality. The objective of this work was to evaluate ecophysiological responses of ´Turiaçu` pineapple plants at the vegetative and reproductive stages to soil fertilization and crop location, and their effects in fruit yield. The study was conducted in the cities of São Luís and Turiaçu, MA, Brazil. Plants under mineral and organic fertilization in two locations, São Luís and Turiaçu, and in two seasons, dry and rainy season, were evaluated during dry and rainy seasons. Chlorophyll index, photochemical efficiency, gas exchange, and fruit yield were evaluated. The pineapple plants presented decrease in the photosynthetic activity, at both developmental stages and in both seasons, when grown in São Luís. The CO2 photosynthetic assimilation decreased. The PSI and PSII activity, according with photosynthetic index, was more sensitive at the reproductive than at the vegetative stage. The organic fertilization was not appropriate for the ´Turiaçu` pineapple crops, regardless of the crop location. The fruit yields were 54.4% and 57.9% lower in São Luís, under mineral and organic fertilization, respectively. Thus, the ecophysiology of ´Turiaçu` pineapple was more affected by water availability than by soil fertility in the municipality of Turiaçu.

RESUMO: O abacaxi é uma fruta tropical com alta demanda pelo mercado de frutas no Brasil. Os frutos da cultivar ´Turiaçu`se destacam nos mercados consumidores locais pela excelente qualidade. O objetivo deste trabalho foi avaliar as respostas ecofisiológicas de plantas de abacaxizeiro ´Turiaçu`nos estádios vegetativo e reprodutivo à adubação do solo e ao local de cultivo, e seus efeitos na produção de frutos. O estudo foi realizado nas cidades de São Luís e Turiaçu, MA, Brasil. Plantas sob adubação mineral e orgânica foram avaliadas durante as estações seca e chuvosa. Foram avaliados teores de clorofila, eficiência fotoquímica, trocas gasosas e produção de frutos. As plantas de abacaxi apresentaram diminuição da atividade fotossintética, em ambas as fases de desenvolvimento e em ambas as estações, quando cultivadas em São Luís. A assimilação fotossintética de CO2 diminuiu. A atividade de PSI e PSII foi mais sensível na fase reprodutiva do que na fase vegetativa. A adubação orgânica não foi adequada para as lavouras de abacaxi ´Turiaçu`, independente do local de cultivo. As produtividades de frutos foram 54,4% e 57,9% menores em São Luís, sob adubação mineral e orgânica, respectivamente. Assim, a ecofisiologia do abacaxi de ´Turiaçu`foi mais afetada pela disponibilidade hídrica do que pela fertilidade do solo no município de Turiaçu.

Resumen Antecedentes: Las poblaciones de Magnolia pugana están disminuyendo, asimismo la precipitación disminuirá 10 % y la temperatura aumentará (2-4 °C) en su área de distribución, de acuerdo al escenario de cambio climático más severo, lo que puede comprometer su germinación. Hipótesis: La interacción del aumento de temperatura y disminución del potencial hídrico reduce y retrasa la germinación de Magnolia pugana. Especie de estudio: Magnolia pugana, endémica del occidente de México, en peligro de extinción. Sitio y año de estudio: Sur de Zacatecas y centro de Jalisco, México. Abril, 2019. Materiales y métodos: Se evaluó la viabilidad de semillas con la prueba de tetrazolio. Se analizó el efecto de temperatura (24, 28 y 37 °C), potencial hídrico (con PEG 8000) (0, -0.3, -0.6, -0.9, -1.2 MPa) y su interacción sobre porcentaje y tiempo medio de germinación, con ANOVA factoriales. Resultados: La viabilidad fue 80 %. Las interacciones entre temperatura y potencial hídrico sobre porcentaje y tiempo medio de germinación fueron significativas. No hubo germinación a 37 °C. El porcentaje de germinación más alto (78 %) se produjo a 24 °C y -0.3 MPa, el menor (3 %) a 28 °C y -0.6 MPa. A 24 °C y 0 MPa germinaron en menor tiempo (23.9 ± 1.5 días), a 28 °C y -0.9 MPa se retrasó 1.5 veces. Conclusiones: La interacción entre bajo potencial hídrico y aumento de temperatura redujo la germinabilidad de Magnolia pugana, condiciones previstas por futuros escenarios de cambio climático, con esto su vulnerabilidad a la extinción podría aumentar.

Abstract Background: Magnolia pugana populations are declining, in addition, it is estimated that precipitation will decrease by up to 10 % and temperatures will increase (2-4 °C) under the most severe climate change scenario, which may affect germination. Hypotheses: The interaction of increased temperature and decreased water potential reduces and delays the germination of Magnolia pugana seeds. Studied species: Magnolia pugana, an endangered species endemic to western Mexico. Study site and dates: Southern Zacatecas and central Jalisco, Mexico. April 2019. Materials and methods: Seed viability was evaluated with tetrazolium test. In addition, the effects of temperature (24, 28, and 37 °C), water potential with PEG 8000 (0, -0.3, -0.6, -0.9, -1.2 MPa) and its interaction on the percentage and mean germination time were analyzed with factorial ANOVA tests. Results: Viability was 80 %. The interactions between temperature and water potential on germination percentage and mean germination time were significant. There was no germination at 37 °C. The highest germination (78 %) was at 24 °C and -0.3 MPa, while the lowest (3 %) was at 28 °C and -0.6 MPa. The control treatment (24 °C and 0 MPa) facilitated germination in a shorter time (23.9 ± 1.5 days). At 28 °C and -0.9 MPa, the mean germination time was slowed by 1.5 times. Conclusions: Magnolia pugana germinability was reduced by the interaction between low water potentials and increased temperature, conditions predicted by future climate change scenarios, therefore its vulnerability to extinction could increase.

Resumen Introducción: La marcada estacionalidad en las especies de sabana puede estimular respuestas fisiológicas que maximicen el metabolismo fotosintético y la productividad. Sin embargo, esas respuestas fisiológicas están vinculadas al estado fenológico de toda la planta, incluidas las fenofases de las hojas. Objetivo: Estudiar cómo los rasgos fisiológicos influyen en el tiempo de la fenofase entre especies de sabana congenéricas y concurrentes. Métodos: Evaluamos la fenología y características fisiológicas de poblaciones de Byrsonima intermedia, B. coccolobifolia y B. verbascifolia. Las mediciones fisiológicas se realizaron al inicio de la estación seca y lluviosa, y de nuevo al final de la estación. Resultados: B. intermedia y B. coccolobifolia se clasificaron como brevicaducifolias y B. verbascifolia como perennifolias. El rendimiento cuántico máximo para B. intermedia y B. coccolobifolia fueron más bajos durante la época seca. Al inicio del período seco, se observaron niveles de pigmentos cloroplastídicos más altos, aunque los niveles de clorofila disminuyeron a medida que avanzaba la estación seca, las proporciones clorofila/carotenoides totales fueron más bajas y los contenidos de carotenoides más altos. Detectamos valores bajos de contenido de almidón al inicio de la época lluviosa, que coincide con la reanudación del crecimiento de la planta. A dos meses de esta época, las hojas estaban en su máxima madurez estructural y funcional, con altos valores de polisacáridos solubles en agua y tasas fotosintéticas, y almacenaban grandes cantidades de almidón. Conclusiones: Las estrategias fisiológicas y fenológicas de las hojas de las especies de Byrsonima estaban relacionadas con la resistencia a la sequía y la aclimatación a la estacionalidad de los recursos hídricos de la sabana. Las oscilaciones de los parámetros cuantificados durante el año indicaron una fuerte relación con la estacionalidad hídrica y con los estados fenológicos de las hojas.

Abstract Introduction: Defined seasonality in savanna species can stimulate physiological responses that maximize photosynthetic metabolism and productivity. However, those physiological responses are also linked to the phenological status of the whole plant, including leaf phenophases. Objective: To study how physiological traits influence phenophase timing among congeneric and co-occurring savanna species. Methods: We evaluated the leaf phenology and physiological traits of populations of Byrsonima intermedia, B. coccolobifolia, and B. verbascifolia. Physiological measurements were performed at the onset of the dry and rainy seasons and again late in the season. Results: B. intermedia and B. coccolobifolia were classified as brevideciduous and B. verbascifolia as evergreen. The maximum quantum yield for B. intermedia and B. coccolobifolia were lowest during the dry season. At the onset of the dry period, the highest chloroplastidic pigment levels were observed, which decreased as the season advanced, total chlorophyll/carotenoid ratios were lowest, and carotenoid contents were highest. We detected low starch content values at the start of the rainy season, coinciding with the resumption of plant growth. Two months into this season, the leaves were at their peak structural and functional maturity, with high water-soluble polysaccharide values and photosynthetic rates, and were storing large amounts of starch. Conclusions: Physiological and leaf phenological strategies of the Byrsonima species were related to drought resistance and acclimatization to the seasonality of savanna water resources. The oscillations of the parameters quantified during the year indicated a strong relationship with water seasonality and with the phenological status of the leaves.

ABSTRACT The objective of this work was to evaluate the growth in plant height, stem base diameter, survival rate, and ecophysiology of Acacia mangium and Mimosa caesalpiniifolia plants with and without inoculation with arbuscular mycorrhizal fungi (Rhizophagus clarus) in areas degraded by mining in the municipality of Itaporanga D’Ajuda, SE, Brazil. The experiment was conducted with plants grown with spacing of 3 × 3 m in areas degraded by sand and gravel mining in Itaporanga D’Ajuda, using plants of the species Acacia mangium and Mimosa caesalpiniifolia. Four treatments were used: Acacia mangium without AMF; Mimosa caesalpiniifolia without AMF; Acacia mangium with AMF; Mimosa caesalpiniifolia with AMF. Plants from each treatment were evaluated for plant height, stem base diameter, survival rate and ecophysiological parameters at 12 months after planting. The forest legume Mimosa caesalpiniifolia inoculated with mycorrhizal fungi (Rhizophagus clarus) presented the best results in plant height, survival rate, and photosynthetic efficiency, at twelve months after planting. Plants in the treatment with Acacia mangium without inoculation with mycorrhizal fungi (Rhizophagus clarus) had the largest stem base diameters and second highest plant heights. However, the lowest survival rate of the plants may have caused overestimation of the results of stem base diameter and plant height.

RESUMO O objetivo deste estudo foi avaliar o crescimento em altura, diâmetro, a taxa de sobrevivência e a ecofisiologia de Acacia mangium e Mimosa caesalpiniifolia inoculadas com fungos micorrízicos arbusculares (Rhizophagus clarus) e sem inoculação em área degradada de mineração no município de Itaporanga D’Ajuda, SE. O experimento foi implantado no espaçamento de 3x3 m em uma área degradada por mineração de areia e cascalhos no município de Itaporanga D’Ajuda, SE com as espécies Acacia mangium (Acacia) e Mimosa caesalpiniifolia (Sabiá). Foram definidos quatro tratamentos: Acacia mangium sem FMA; Mimosa caesalpiniifolia sem FMA; Acacia mangium com FMA; Mimosa caesalpiniifolia com FMA. As plantas de cada tratamento foram avaliadas quanto à altura da planta, diâmetro da base do caule, taxa de sobrevivência e parâmetros ecofisiológicos aos 12 meses após o plantio, utilizando 5 plantas selecionadas ao acaso por tratamento. Doze meses após o plantio conclui-se: a leguminosa florestal Mimosa caesalpiniifolia inoculada com fungos micorrízicos Rhizophagus clarus apresentou os melhores resultados em altura, taxa de sobrevivência e eficiência fotossintética. A Acacia mangium sem inoculação com fungos micorrízicos Rhizophagus clarus teve o maior diâmetro e a segunda maior altura. Porém a menor taxa de sobrevivência pode ter superestimado os resultados de diâmetro e altura.

Resumen Antecedentes: La presencia de petróleo crudo (PC) en el suelo puede conllevar la muerte de especies vegetales que no logran aclimatarse a estas condiciones. Preguntas: ¿Cuál será la respuesta fisiológica de dos especies arbóreas creciendo en un suelo contaminado con diferentes concentraciones de PC? ¿Cuál será su plasticidad fisiológica en este contexto? Especies de estudio: Haematoxylum campechianum L. y Tabebuia rosea (Bertol.) DC. Sitio de estudio: Tabasco, México; 2017. Métodos: Se evaluaron variables fisiológicas en dos especies arbóreas establecidas en suelos contaminados bajo tres concentraciones de PC (15,170 a 15,600 mg kg-1) durante 292 días; se midió la asimilación de CO2 (A), transpiración (E), eficiencia en el uso del agua (EUA), eficiencia cuántica del fotosistema II (Fv/Fm y ΦPSII ), tasa de transporte de electrones (TTE), disipación no fotoquímica de energía (DNE), potencial hídrico, osmótico y contenido de clorofila. Resultados: Se encontró baja plasticidad fisiológica en ambas especies; hubo un efecto hormesis donde, en la concentración más baja de PC, los individuos presentaron un desempeño fisiológico superior comparado con plantas del tratamiento control. En T. rosea se registró un incremento en A, E, ΦPSII, DNE y Fv/Fm y una reducción en la TTE hacia el final del experimento en todos los tratamientos. H. campechianum presentó un incremento en la concentración de clorofila al final del mismo. Conclusiones: Tabebuia rosea presentó mayor variabilidad en sus respuestas fisiológicas comparada con H. campechianum, lo que sugiere que la primera podría ser más vulnerable a la presencia de petróleo crudo en suelo.

Abstract Background: The presence of crude oil (CO) in the soil can lead to the death of plant species that cannot acclimate to these conditions. Questions: What will be the physiological response of two tree species growing in soil contaminated with different concentrations of CO? What will be its physiological plasticity in this context? Study species: Haematoxylum campechianum L. and Tabebuia rosea (Bertol.) DC. Study site: Tabasco, Mexico; 2017. Methods: The physiological performance of two tree species growing in contaminated soils subjected to different concentrations of CO (15,170 to 15,600 mg kg-1) for 292 days was evaluated; we measured CO2 assimilation (A), transpiration (E), water use efficiency (EUA), quantic efficiency of photosystem II (Fv/Fm and ΦPSII), electron transport rate (TTE), non-photochemical quenching (DNE), water and osmotic potential, and chlorophyll content. Results: Low physiological plasticity was found in both species; there was a hormesis effect where individuals in the lower concentration of CO presented a physiological performance superior compared with plants in the control treatment. In T. rosea, there was an increase in the assimilation and transpiration rate, ΦPSII, DNE and Fv/Fm towards the end of the experiment; the TTE decreased from the beginning to the end of the experiment in all treatments. H. campechianum showed an increase in chlorophyll concentration towards the end of the experiment. Conclusions: Tabebuia rosea showed greater variability in their physiological response compared to H. campechianum, which suggests that they could be more sensitive to the presence of crude oil in the soil.

ABSTRACT The most severe drought of this century in the Amazon rainforest, which was caused by El Niño, occurred from 2015 to 2016. With a focus on the ecophysiology of the regrowth of the Brazil nut tree, Bertholletia excelsa, it was investigated how the progression of the drought of 2015-2016 affected the physiological traits of the coppice regrowth of B. excelsa. The experiment was carried out in a ten-year-old plantation of Brazil nut trees, which had been subjected to thinning and coppice regrowth two years earlier. In the sprouts grown on the stumps of cut trees, the following treatments were applied: (T1) thinning to one sprout per stump; (T2) thinning to two sprouts per stump, and (T3) maintenance of three sprouts per stump. Thinning treatments did not alter the growth and ecophysiological traits of the Brazil nut tree sprouts, though the phosphorus content of the leaves was higher in T1. However, the progression of the drought in 2015-2016 negatively affected the growth (height) and gas exchange of sprouts of all treatments. In addition, an increase of around 37% was observed in the intrinsic water-use efficiency. Concerning photochemical performance, no alterations were observed. Therefore, drought stress promoted a negative effect on sprout growth and affected traits related to the photosynthesis of the B. excelsa sprouts independently of the number of sprouts per stump.

RESUMO A seca mais severa deste século na floresta amazônica, causada por El Niño, ocorreu de 2015 a 2016. Com foco na ecofisiologia da rebrota da castanheira da Amazônia, foi investigado como a progressão da seca de 2015-2016 afetou as características fisiológicas das rebrotas de uma talhadia de B. excelsa. O experimento foi realizado em uma plantação de castanheiras com dez anos, a qual havia sido submetida a um desbaste e rebrota de talhadia dois anos antes. Nas rebrotas crescidas sobre os tocos das árvores cortadas foram aplicados os seguintes tratamentos: (T1) desbrota para manter um broto por cepa; (T2) desbrota para manter dois brotos por cepa; e (T3) manutenção de três brotos por cepa. Os tratamentos de desbrota não alteraram o crescimento e as características ecofisiológicas dos brotos da castanheira, exceto para o teor foliar de fósforo, que foi maior em T1. Porém, a progressão da seca em 2015-2016 afetou negativamente o crescimento em altura e as trocas gasosas dos brotos de todos os tratamentos. Além disso, foi observado um aumento de cerca de 37% na eficiência intrínseca do uso da água. Quanto ao desempenho fotoquímico, não foram observadas alterações. Portanto, o estresse hídrico promoveu efeito negativo no crescimento da brotação e afetou características relacionadas à fotossíntese das brotações de B. excelsa, independentemente do número de brotações por cepa.

Resumo Dipteryx alata Vogel é uma arbórea de ampla ocorrência no Cerrado, se estabelecendo preferencialmente em solos bem drenados. Estudos referentes à ecofisiologia de D. alata em podem contribuir para a tomada de decisão sobre o uso de mudas dessa espécie em programas de recuperação de áreas degradadas sujeitas a alagamento temporário. Objetivamos com essa pesquisa avaliar os efeitos do alagamento no metabolismo fotossintético e antioxidante, além da qualidade de mudas dessa espécie, cultivadas ou não sob alagamento durante quatro períodos de avaliação (0, 20, 40 e 60 dias) seguidos de 100 dias após o término de cada período (0+100, 20+100, 40+100, 60+100 dias), possibilitando verificar o potencial de recuperação pós-alagamento. Observamos que as plantas alagadas apresentaram menor eficiência fotossintética e danos em FV/FM entretanto houve recuperação dessas características no pós alagamento. A qualidade das mudas reduziu sob alagamento não variando entre os períodos de exposição e embora tenha aumentado no pós-alagamento manteve-se menor não se recuperando. A ocorrência de lenticelas hipertrofiadas associadas a alterações fisiológicas e um eficiente sistema enzimático antioxidante devem ter contribuído para a sobrevivência e recuperação metabólica dessas mudas. Diante disso, sugerimos que a espécie é sensível ao estresse por alagamento, mas capaz de se ajustar e recuperar as características metabólicas 100 dias após a suspensão deste estresse hídrico, no entanto a qualidade da mudas não apresentou recuperação, assim, sugerimos plasticidade diante da condição de cultivo e ressaltamos que o tempo de 100 dias não é suficiente para a completa retomada do crescimento.

Abstract Dipteryx alata Vogel is a tree species widely found in Cerrado, settling preferentially in well drained soils. Studies related to ecophysiology of D. alata may contribute to the decision making about using seedlings of this species in projects aimed at the recovery of degraded areas where seasonal flooding happens. This study aimed to assess the effects of flooding on photosynthetic and antioxidant metabolism and quality of D. alata seedlings cultivated or not under flooding during four assessment periods (0, 20, 40, and 60 days), followed by 100 days after the end of each assessment period (0+100, 20+100, 40+100, and 60+100 days), allowing verifying the potential for post-flooding recovery. Flooded plants showed lower photosynthetic efficiency than non-flooded plants, regardless of the periods of exposure. However, this efficiency was recovered in the post-flooding, with values similar to that of the non-flooded seedlings. Moreover, the damage to FV/FM was evidenced by an increase in the period of exposure to flooding, but recovery was also observed at this stage of the photosynthetic metabolism. Seedling quality decreased under flooding, not varying between periods of exposure, but remained lower although the increase observed in the post-flooding period, with no recovery after flooding. The occurrence of hypertrophied lenticels associated with physiological changes and an efficient antioxidant enzyme system might have contributed to the survival and recovery of these seedlings. Thus, this species is sensitive to flooding stress but capable of adjusting and recovering metabolic characteristics at 100 days after the suspension of the water stress, but with no recovery in seedling quality. Thus, we suggested plasticity under the cultivation condition and determined that the time of 100 days is not enough for the complete resumption of growth.

ABSTRACT Grafting can be an ally in the vegetable’s soilless cultivation, being the objective of this work evaluate the growth and production, as well as to define the thermal sum and trophic limit of grafted and non-grafted tomato plants cultivated in substrate. The experiments were conducted in a protected environment in the city of Jaguari-RS, in two growing seasons in the years 2019 and 2020. Italian and Gaucho tomato cultivars were used, the rootstock was chosen for giving vigor and longevity to the plants. Yield data were obtained through weekly fruit harvesting, growth data through periodic collections of whole plants and the total biomass obtained at the end of the experiments. Grafted plants show greater vegetative growth regardless of the crop season; however, non-grafted plants are more productive in a growing cycle with restricted light and low temperatures. Grafted plants require a greater thermal sum to complete their phenological stages. The trophic limit for grafted and non-grafted plants of Italian and Gaucho tomato cultivars is 4.8 MJ/m2/day.

RESUMO A enxertia pode ser uma aliada no cultivo sem solo de hortaliças, sendo o objetivo deste trabalho avaliar o crescimento e a produção, assim como definir a soma térmica e o limite trófico de plantas enxertadas e não enxertadas de tomateiro cultivadas em substrato. Os experimentos foram conduzidos em ambiente protegido na cidade de Jaguari-RS, em duas safras de cultivo nos anos 2019 e 2020. Foram utilizadas cultivares de tomateiro do tipo italiano e gaúcho, o porta enxerto foi escolhido por conferir vigor e longevidade às plantas. Os resultados produtivos foram obtidos por meio da colheita semanal dos frutos, os dados de crescimento por meio de coletas periódicas de plantas inteiras e a biomassa total obtida ao final dos experimentos. As plantas enxertadas apresentam maior crescimento vegetativo independente da safra de cultivo, no entanto, as plantas não enxertadas são mais produtivas em ciclo de cultivo com restrição de luminosidade e baixas temperaturas. As plantas enxertadas exigem maior soma térmica para completar seus estádios fenológicos. O limite trófico para plantas enxertadas e de pé franco das cultivares de tomateiro do tipo italiano e gaúcho é de 4,8 MJ/m2/dia.

ABSTRACT Several abiotic factors, such as water availability, significantly affect the development of forest species found in the understory. This research aimed to evaluate morphophysiological characteristics in plants of Erythroxylum pauferrense submitted to different water regimes. The experiment was developed in a greenhouse at the Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil. The experimental design was in randomized blocks, with five water treatments [100%, 80%, 60%, 40% and 20% of the pot capacity (PC)] and four replications. Growth attributes, morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indices were evaluated. The data were submitted for analysis of variance, and in cases of significance, polynomial regression analyses were performed. The plants of Erythroxylum pauferrense submitted to 100% and 80% water levels of the PC present greater development and morphophysiological performance. In comparison, the evaluated parameters were significantly reduced in the regime of greater water stress (20% of the PC). Thus, the water regime of 80% of PC is the most recommended for producing seedlings of Erythroxylum pauferrense, promoting greater growth and significant changes in morphofunctional aspects, gas exchange, chlorophyll fluorescence and chlorophyll indexes.

RESUMO Vários fatores abióticos, como a disponibilidade de água, afetam significativamente o desenvolvimento das espécies florestais encontradas no sub-bosque. Esta pesquisa teve como objetivo avaliar características morfofisiológicas em plantas de Erythroxylum pauferrense submetidas a diferentes regimes hídricos. O experimento foi desenvolvido em casa de vegetação na Universidade Federal da Paraíba, Campus II, Areia, Paraíba, Brasil. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos hídricos [100%, 80%, 60%, 40% e 20% da capacidade do vaso (PC)] e quatro repetições. Foram avaliados atributos de crescimento, aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila. Os dados foram submetidos à análise de variância e, nos casos de significância, análises de regressão polinomial. As plantas de Erythroxylum pauferrense submetidas a regimes hídricos de 100% e 80% da PC apresentam maior desenvolvimento e desempenho morfofisiológico. Em comparação, os parâmetros avaliados foram significativamente reduzidos no regime de maior estresse hídrico (20% da PC). Assim, o regime hídrico de 80% de PC é o mais recomendado para produção de mudas de Erythroxylum pauferrense, promovendo maior crescimento e alterações significativas nos aspectos morfofuncionais, trocas gasosas, fluorescência da clorofila e índices de clorofila.

ABSTRACT Physalis angulata L. (Solanaceae), known as ‘camapu’, has pharmacological and agroindustrial potentials, but information on the ecophysiological aspects that influence germination is scarce. In this context, the objective was to evaluate the expression of the physiological potential of P. angulata seeds as a function of the maturation stage, temperature, substrate and light condition. Four experiments were conducted: in the first, the maturation stages (green calyx + fruit, yellow calyx + fruit and light brown calyx + fruit) were evaluated at temperatures of 25, 30 and 35 °C, separately; in the second, the interaction between the temperatures of 35, 40 and 45 °C and types of substrate (on paper, between paper and between vermiculite) was tested in a 3x3 factorial scheme (temperatures as the first factor and types of substrates as the second factor); in the third experiment, the effect of light (absence of light, white light, red and far-red light) was evaluated; and, in the fourth, increasing values of photoperiods (0, 8, 12 and 16 hours) were used. In all experiments, the design was completely randomized with four replicates of 50 seeds. Analysis of the results showed that there was no interaction between the temperatures and the substrates tested, demonstrating the isolated action of the factors. P. angulata seeds expressed better physiological potential when the calyx and fruit are yellow. In the germination test, the seeds should be sown between paper towels, under temperature of 35 °C and absence of light.

RESUMO Physalis angulata L. (Solanaceae), conhecida por camapu, possui potenciais farmacológico e agroindustrial, porém são escassas as informações sobre os aspectos ecofisiológicos que influenciam a germinação. Neste sentido, objetivou-se avaliar a expressão do potencial fisiológico de sementes de P. angulata em função do estádio de maturação, temperatura, substrato e condição luminosa. Para isso, conduziram-se quatro experimentos: no primeiro, avaliou-se os estádios de maturação (cálice + fruto verdes, cálice + fruto amarelos e cálice + fruto marrom-claros) nas temperaturas de 25; 30 e 35 °C, separadamente; no segundo, testouse a interação entre as temperaturas 35; 40 e 45°C e tipos de substrato (sobre papel, entre papel e entre vermiculita) em esquema fatorial 3x3 (sendo o primeiro fato as temperaturas e o segundo os tipos de substratos); no terceiro experimento, avaliou-se o efeito da luz (ausência de luz, luz branca, luz na frequência do vermelho e do vermelho-distante); e, no quarto, utilizaram-se valores crescentes de fotoperíodos (0; 8; 12 e 16 horas). Em todos os experimentos o delineamento foi o inteiramente casualizado com quatro repetições de 50 sementes. Na análise dos resultados foi visto que não houve interação entre as temperaturas e os substratos testados, demonstrando a atuação isolada dos fatores. As sementes de P. angulata expressaram melhor potencial fisiológico quando o cálice e o fruto estão amarelos. No teste de germinação, as sementes devem ser semeadas entre papel toalha, sob a temperatura de 35 °C e ausência de luz.

RESUMO Em um ano típico na Amazônia central, há uma estação seca amena, mas seu efeito sobre o crescimento do tronco de espécies de uso múltiplo ainda é pouco conhecido. Este estudo teve como objetivo determinar o efeito individual de variáveis microclimáticas sobre crescimento do tronco após remover a influência da intercorrelação entre os fatores climáticos. O incremento mensal do diâmetro do tronco foi medido em seis espécies (46 árvores) de janeiro de 2018 a dezembro de 2020. As variáveis microclimáticas medidas foram irradiância, temperatura do ar, precipitação pluvial e déficit de pressão de vapor. Utilizou-se regressão de componentes principais para avaliar o efeito da variabilidade micrometeorológica sobre crescimento do tronco. Em média, o crescimento do tronco aumentou com o aumento da precipitação e do conteúdo de água do solo, mas diminuiu com o aumento da temperatura máxima e do déficit máximo de pressão de vapor. Estes resultados indicam que, removendo o efeito da intercorrelação entre os parâmetros climáticos, o déficit de pressão de vapor pode, de fato, ter um efeito sobre o crescimento do tronco. Demonstrou-se que a redução no crescimento do caule durante a estação seca também pode estar relacionada ao aumento da temperatura máxima e do déficit máximo de pressão de vapor, e não apenas ao declínio do teor de água no solo.

ABSTRACT In a typical year in the central Amazon, there is a mild dry season, but its effect on stem growth of multipurpose forest tree species is not yet well known. This study aimed to determine the individual effect of microclimatic parameters on stem growth after removing the influence of intercorrelation among microclimatic variables. Monthly stem diameter increment was measured in six species (46 trees) from January 2018 to December 2020. Microclimatic variables recorded were irradiance, air temperature, rainfall, and vapor pressure deficit. Principal component regression was used to assess the effect of micrometeorological variability on stem growth. On average, stem growth increased with an increase in rainfall and soil water content, but decreased with rise in maximum temperature and maximum vapor pressure deficit. These findings indicate that, when removing the effect of intercorrelation between microclimatic parameters, vapor pressure deficit may, in fact, affect stem growth. We demonstrate that the reduction in stem growth during the dry season can also be related to an increase in maximum temperature and maximum vapor pressure deficit, and not only to a decline in soil water content.

Resumen El mildiu velloso (Peronospora belbahrii) afecta el desarrollo de la albahaca (Ocimum basilicum) y su control es complicado, debido al uso restringido de fungicidas. El objetivo de este estudio fue someter semillas de albahaca variedad Nufar a tratamientos de termoacondicionamiento de 40, 50 y 60°C expuestas a diferentes intervalos de tiempo (30, 60 y 90 min) para evaluar la relación existente entre la aparición de los síntomas de la enfermedad con la humedad relativa y temperatura ambiente, así como el efecto de los tratamientos de preacondicionamiento de la semilla en la severidad e incidencia de la enfermedad en la planta, y su respuesta fisiológica. Las semillas se sembraron en macetas bajo malla sombra y cuando las plantas alcanzaron 15 cm de crecimiento, se infectaron con P. belbahrii. La incidencia de la enfermedad se determinó semanalmente y 60 días después de la siembra se determinaron las variables morfométricas y fisiológicas mostrando diferencias significativas entre temperatura, tiempo de exposición e interacción en la mayoría de las variables evaluadas. Se observó una disminución en la incidencia de la enfermedad en plantas de semillas sometidas a condicionamiento térmico tratadas a 60°C por 60 min de exposición. Este mismo tratamiento mostró menor apertura estomática y transpiración y mayor concentración subestomatal de CO2, lo que sugiere una probable relación con la entrada de P. belbahrii a la hoja disminuyendo su incidencia.

Abstract Downy mildew (Peronospora belbahrii) affects severely the development of Ocimum basilicum; its control is complicated due to the restricted use of fungicides. The objective of this study was to subject basil var. Nufar seeds to thermopriming treatments at 40, 50 and 60°C in different exposure time intervals (30, 60 and 90 min) to assess the existing relationship between disease symptom emergence and relative humidity, environmental temperature and seed pre-conditioning treatment effects on plant disease severity, incidence and physiological response. The seeds weresowed in mesh house pots and when plants reached 15 cm, they were infected with P. belbahrii. Disease incidence was determined weekly; at 60 days after sowing, morphometric and physiological variables were determined showing significant differences between temperature, exposure time and interaction in the majority of the variables assessed. A decrease in disease incidence was observed in plants from seed thermopriming treated at 60°C for 60 min of exposure. This same treatment was found to show less stomatal opening and transpiration and greater substomatal concentration of CO2, which suggested a probable relationship P. belbahrii entering the leaf decreasing its incidence.

Resumen El objetivo de este trabajo fue evaluar la capacidad competitiva de cultivares de frijol tipo carioca, BRS FC104, BRS FC402, IAC Imperador, IAC Milênio, IPR Tangará y SCS Riqueza, bajo niveles crecientes de infestación de Alexandergrass (Urochloa plantaginea). Los experimentos se realizaron en condiciones de invernadero en un diseño completamente al azar con cuatro repeticiones. Los tratamientos se organizaron en proporciones de plantas de frijol y Alexandergrass de: 100: 0, 75:25, 50:50, 25:75 y 0: 100 o 40:00, 30:10, 20:20, 10:30 y 0: 40 plantas por maceta. El análisis de la competitividad de las especies se realizó mediante diagramas aplicados a experimentos de series de reemplazo y también mediante los índices de competitividad relativa. Treinta días después de la emergencia del cultivo, se midieron el área foliar (AF), la altura de la planta (AP), el diámetro de la planta (DP) y la masa seca de los brotes (MS), además de características relacionadas con la fisiología de la planta. Hubo competencia entre cultivares de frijol carioca en presencia de Alexandergrass, independientemente de la proporción de plantas, lo que provocó reducciones en el DP, AF, y MS. Básicamente, existe competencia por los mismos recursos ambientales entre el cultivo de frijoles y Alexandergrass.

Abstract The objective of this work was to evaluate the competitive ability of carioca bean cultivars BRS FC104, BRS FC402, IAC Imperador, IAC Milênio, IPR Tangará, and SCS Riqueza in the presence of Alexandergrass (Urochloa plantaginea) in different proportions of plants in association. The experiments were carried out in a greenhouse in a completely randomized design with four replications. The treatments were arranged according to the proportions of beans and Alexandergrass plants: 100:0, 75:25, 50:50, 25:75, and 0:100 or 40:00, 30:10, 20:20, 10:30, and 0:40 plants per pot. The competitiveness of the species was analyzed using diagrams applied to replacement experiments and also through relative competitiveness indices. At 30 days after crop emergence, leaf area (LA), height (HP), diameter (DP), and shoot dry mass (SM) of the plant shoots were measured, as well as variables related to the physiology of the species. There was competition among carioca bean cultivars in the presence of Alexandergrass regardless of the proportion of plants, causing decreases in DP, LA and SM. Basically, there is competition for the same environmental resources between beans and Alexandergrass.

RESUMEN La manzana ‘Anna’ es una variedad de bajo requerimiento térmico (250 a 300 horas frío ≤7,2ºC). Esta posee beneficios importantes para la salud y tiene un gran potencial en zonas tropicales y subtropicales, afectadas por el cambio climático. En esta revisión, se pretende presentar la importancia del cultivo de manzano ‘Anna’, los cambios fenológicos y ecofisiológicos, y el estado actual en el manejo agronómico cuando se trabajan cosechas continuas en condiciones del trópico alto. En zonas altas tropicales, esta variedad de manzano presenta dos cosechas en un año en zonas con condiciones ambientales específicas e implementando un manejo particular. Bajo la producción de estas cosechas continuas, se realizan algunas prácticas agronómicas durante la fenología productiva para que el manzano no ingrese a una endodormancia, dichas prácticas son estrés hídrico - defoliación - agobio de ramas y aplicación de compensadores de frío (inductores de brotación floral). En Colombia, esta variedad fue introducida en 1985 y se cultiva bajo condiciones de temperaturas entre 14 y 20°C, de 1700 a 2800 metros sobre el nivel del mar (m.s.n.m.), precipitación bimodal y monomodal, y brillo solar entre 800 y 2000 horas al año. El desarrollo del fruto y la cosecha es entre 100 a 120 días después de la antesis, con valores de firmeza de 38.38 N, contenido de sólidos solubles de 8.58°Brix y acidez total titulable de 0.7% del fruto. Esta documentación indica una producción favorable y con gran potencial en cuanto al crecimiento y desarrollo, precocidad y calidad del manzano ‘Anna’ en zonas altas colombianas.

ABSTRACT The 'Anna' apple is a variety of low requirements of winter chill (250 to 300 chilling hours ≤7.2C). This apple has essential health benefits and remarkable adaptive potential in tropical and subtropical areas affected by climate change. Thus, this review presents the significance of the 'Anna' apple cultivation, the phenological and eco-physiological modifications, and the current state of agronomic management when continuous crops are managed in tropical highlands. The production of this apple in tropical highlands has outstanding potential to obtain cyclical or continuous harvests (two harvests per year) in certain areas with specific environmental conditions, implementing a particular management system. In plantations, it is crucial to carry out some agronomic practices during the reproductive phenology so that the apple tree does not enter into an endodormancy. These are water stress - defoliation - tie-down branches, and the application of dormancy-breaking agents (flower-inducing compounds). In Colombia, ‘Anna’ variety was introduced in 1985 and is grown in areas with temperatures between 14 and 20°C, altitudes between 1700 and 2800 meters above sea level (m a.s.l.), with bimodal and monomodal rain regimes, and solar brightness between 800 and 2000 hours a year. The harvest is between 100 to 120 days after anthesis, with firmness values of 38.38N, a soluble solids content of 8.58°Brix, and total titratable acidity of 0.7% of the fruit. This documentation indicates a good production with great potential in terms of growth and development, earliness, and quality of the 'Anna' apple tree in Colombian highlands.