RESUMO As flores de corte são produtos delicados cuja qualidade e longevidade dependem das condições de cultivo e pós-colheita. O trabalho foi desenvolvido objetivando-se avaliar o antocrono e a pós-colheita de hastes de gladíolo produzidas sob diferentes épocas de cultivo e níveis de irrigação. Os experimentos foram conduzidos em casa de vegetação no Estado do Rio de Janeiro (Brasil), durante os períodos de inverno/primavera de 2018 e outono/inverno de 2019. O delineamento experimental foi em blocos casualizados, com quatro níveis de irrigação (45%, 60%, 80% e 100% da necessidade hídrica da cultura) e 5 repetições. O manejo da irrigação foi realizado pelo acionador automático para irrigação, instalado no tratamento 100%. A medida em que alcançavam o ponto de colheita, considerado como “mostrando a cor” dos três floretes basais, as hastes florais eram colhidas, sempre no período da manhã, e imediatamente levadas ao laboratório para padronização do tamanho (75 cm). Durante o armazenamento, as hastes foram mantidas à temperatura de 25 ºC, com a base imersa em recipiente contendo 300 mL de água. As avaliações de massa fresca, absorção de água, antocrono e longevidade foram realizadas diariamente, além de uma avaliação visual, realizada por meio de uma escala de senescência proposta. A ocorrência de déficit hídrico acentuado durante o cultivo interfere na massa fresca das hastes em pós-colheita e aumenta a velocidade de abertura das flores. A longevidade das hastes florais é reduzida quando gladíolo é produzido com o nível de irrigação de 45%. Não há diferenças significativas na longevidade das flores cultivadas nas diferentes estações e o valor do antocrono é influenciado pela disponibilidade de água, sendo menor nas hastes mantidas em condição de campo (0,70 a 0,80) em comparação à condição pós-colheita (0,83 a 0,92).

ABSTRACT Cut flowers are delicate products whose quality and longevity depends on growing and postharvest conditions. The aim of the study was to evaluate the anthochron and the postharvest of gladiolus stems produced under different growing seasons and irrigation levels. The experiments were carried out in a greenhouse in the State of Rio de Janeiro (Brazil) during the winter/spring 2018 and autumn/winter 2019 periods. A randomized block design with 5 replications was used, considering irrigation levels of 45%, 60%, 80% and 100% of the crop water requirement. Irrigation management was performed by the automatic irrigation controller, installed in the 100% irrigation level treatment. As they reached the harvest point, considered to be “showing the color” of the three basal florets, the floral stems were harvested, always in the morning, and immediately taken to the laboratory for standardization of size (75 cm). During the storage period, the stems were kept at a temperature of 25 ºC, with the base immersed in a container with 300 mL of water. Fresh mass, water absorption, anthochron and longevity evaluations were performed daily, in addition to a visual evaluation, performed using a proposed senescence scale. The occurrence of severe water deficit during cultivation interferes with the fresh mass of the stems in postharvest and increases the opening speed of the flowers. The floral stems’ longevity is reduced when gladiolus is produced under the 45% irrigation level. There are no significant differences in the longevity of flowers grown in the different seasons and the anthochron value is influenced by the water availability, being lower in the stems kept in field condition (0.70 to 0.80) in comparison to the postharvest condition (0.83 to 0.92).

RESUMO O manejo da irrigação e as condições meteorológicas durante a fase de cultivo desempenham um papel essencial na manutenção da qualidade comercial de flores de corte. Este estudo avalia a necessidade de água, a sensibilidade ao déficit hídrico e a qualidade comercial do gladíolo ‹Amsterdam’ produzido com irrigação automatizada em diferentes períodos de crescimento. O delineamento experimental foi blocos casualizados com cinco repetições, composto pelo fator época de plantio (inverno/primavera de 2018 e outono/inverno de 2019) e o fator níveis de irrigação (45% - L1, 60% - L2, 80% - L3, 100% - L4 da necessidade hídrica da cultura). A irrigação foi feita com uso do acionador automático para irrigação (AAI). No ponto de colheita nós avaliamos as hastes quanto ao diâmetro, número de flores, comprimento do pendão e da haste floral. Foram realizadas também avaliações de condutância estomática, área foliar e duração das fases fenológicas em graus-dias. A aplicação de 100% da necessidade hídrica da cultura em cultivo usando o acionador automático de irrigação no outono/inverno resulta em melhor classificação comercial. O tratamento correspondente a 45% da necessidade hídrica da cultura estendeu a duração total do ciclo do gladíolo. Hastes florais de melhor qualidade comercial são obtidas com 100% da necessidade hídrica da cultura durante o cultivo de outono/inverno.

ABSTRACT Water management and meteorological conditions during the cropping phase play an essential role in maintaining the commercial quality of cut flowers. This study evaluates water requirement, sensitivity to water deficit, and commercial quality of gladiolus ‘Amsterdam’ produced with automated irrigation in different growing periods. The experimental design was in randomized blocks with five replicates and consisted of the growing period factors (winter/spring 2018 and autumn/winter 2019) and the irrigation level factors (45% - L1, 60% - L2, 80% - L3, and 100% - L4 of crop water requirement). An automatic irrigation controller was used for irrigation management. At the harvest point, we evaluated the stems for the diameter, number of flowers, spike length, and floral stem length. We also evaluated stomatal conductance, leaf area, and duration of phenological phases on degree-days. The application of 100% crop water requirement using an automatic irrigation controller in the autumn/winter cycle results in better commercial classification. The treatment with 45% of the crop water requirement extended the total duration of the cycle. In conclusion, flower stems of better commercial classification are obtained with 100% of crop water requirement during the autumn/winter cycle.

ABSTRACT: Records of changes in the phytosociological structure of vegetation can be observed more clearly in soils that have more significant accumulation of organic matter, like those occurring in high-mountain environments. The aim of this study was to characterize soils formed in high-mountain environments in the Itatiaia National Park (INP), state of Rio de Janeiro, southeastern Brazil, and to discuss the potential of preserved phytoliths as markers of vegetative history and environmental factors. Four profiles were selected, which were morphologically described and evaluated for their physical and chemical properties. For phytolith analysis and high-resolution determination of the stable carbon isotopes, samples were collected at 0.10 m intervals. The profiles showed highly similar morphological characteristics, with peat deposits and colluvial sediments as source material, produced in the highest parts of the landscape. High-mountain soils in the INP have properties related to high contents of organic matter, like high acidity, low base saturation, and high CEC values due to high H+ contents. The soils are formed by the addition of plant residues, which accumulate due to the cold and humid climate during most of the year in these environments. The phytolith assemblage had a high frequency of morphotypes characteristic of temperate, cold, and high elevation intertropical regions, especially of Pooideae plants. The phytolith indexes indicated open vegetation environments with a predominance of C3 grasses, suggesting cold climate conditions, and corroborating the δ13C isotopic values. The results of phytolith analysis of the profiles reflected characteristics related to soil genesis. Organism is the main soil formation factor, conditioned by the factors relief (elevation) and climate, which resulted in low temperatures and lead organic matter accumulation.