Main conclusion Macauba palm fruiting is supra-annual, and the fruit growth follows a double sigmoidal trend. The prevailing compound in the mesocarp differs as the fruit ages, oil being the major storage compound. Acrocomia aculeata, macauba palm, is a conspicuous species in the tropical Americas. Because the species is highly productive in oil-rich fruits, it is the subject of domestication as an alternative vegetable oil crop, especially as a bioenergy feedstock. This detailed study first presents the macauba fruit growth and development patterns, morphological changes and accumulation of organic compounds. Fruits were monitored weekly in a natural population. The fruiting was supra-annual, and the fruit growth curve followed a double sigmoidal trend with four stages (S): SI-slow growth and negligible differentiation of the fruit inner parts; SII-first growth spurt and visible, but not complete, differentiation of the inner parts; SIII-growth slowed down and all structures attained differentiation; and SIV-second growth spurt and fruit maturation. In SII, the exocarp and endocarp were the main contributors to fruit growth, whereas the mesocarp and endosperm were responsible for most of the weight gain during SIV. In comparison with starch and oil, soluble sugars did not accumulate in the mesocarp. However, starch was transitory and fueled the oil synthesis. The protective layers, the exocarp and endocarp, fulfilling their ecological roles, were the first to reach maturity, followed by the storage tissues, the mesocarp, and endosperm. The amount and nature of organic compounds in the mesocarp varied with the fruit development and growth stages, and oil was the main and final storage material. The description of macauba fruit's transformations and their temporal order may be of importance for future ecological and agronomical references.

ABSTRACT. Flavonoids, the pharmaco-active compounds studied in this work, in general, are located in the shoots as natural pigments that protect the plants from damage by oxidizing agents. The experiment was conducted in the greenhouse of the Fitotecnia Department, Federal University of Viçosa, Minas Gerais Staty. The experimental design was completely randomized with five treatments and five replications. The treatments were the time of harvest: zero, three, six, nine, and twelve days after anthesis (DAA). The height of the plant (mm), stem diameter (mm), number of leaves and total flavonoid content (%, w w -1 ) were determined. We developed growth curves for calendula with growth behavior assessed through time for height, stem diameter and number of leaves. The time of the harvest season positively influenced the total flavonoid contents and the average productivity of flowers, and the highest content of flavonoids was found three DAA. The average productivity of the flowers and the accumulation of flavonoids were heterogeneous among harvest times (0, 3, 6, 9 and 12 days after anthesis). The highest yield of flavonoids was obtained three days after anthesis; therefore, a harvest of the inflorescences is recommended every three days.Keywords: secondary metabolism, phenolic compounds, harvest season, plant performance.Crescimento, desenvolvimento e teor de flavonoides em calêndula (Calendula officinalis L.) RESUMO. Os compostos fármaco-ativos estudado no trabalho, os flavonoides, de maneira geral, estão localizados na parte aérea das plantas. São pigmentos naturais presentes nos vegetais e protegem o organismo do dano por agentes oxidantes. O experimento foi conduzido na casa de vegetação do Departamento de Fitotecnia da Universidade Federal de Viçosa, MG. O delineamento utilizado foi o inteiramente casualizado, com cinco tratamentos e cinco repetições. Os tratamentos foram as épocas de colheita: zero, três, seis, nove e doze dias após a antese (DAA). Foram avaliadas a altura da planta (mm), o diâmetro do caule (mm), o número de folhas e o teor total de flavonoides (%, p p -1 ). Foi realizada a curva de crescimento da calêndula e seu desempenho quanto à altura, diâmetro e número de folhas ao longo do tempo de avaliação. A época de colheita influenciou positivamente no teor total de flavonoides e na produtividade média dos capítulos florais, sendo que aos três DAA foi encontrado maior teor de flavonoides. A resposta foi heterogênea entre as épocas de colheita (0, 3, 6, 9 e 12 dias após a antese) quanto à produtividade média das flores e o acúmulo de flavonoides. Aos três dias após a antese obteve-se a maior produtividade de flavonoides, portanto aconselha-se que a colheita das inflorescências seja feita a cada três dias.Palavras-chave: metabolismo secundário, compostos fenólicos, época de colheita, desempenho vegetal.

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water‐use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water‐use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water‐use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree‐days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water‐use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.

<p>O objetivo deste trabalho foi identificar as espécies de besouros coletados em uma população nativa de macaúba (<em>Acrocomia aculeata</em> (Jacq.) Lodd), bem como caracterizar suas atividades, para futuros estudos da interação planta x inseto. Indivíduos adultos do gorgulho dos frutos e do besouro pardo foram capturados manualmente nos frutos e nos folíolos de plantas adultas de macaúba. Os insetos foram associados com o abortamento prematuro dos frutos e com a redução da área fotossintetizante das plantas.</p>

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In intercropping systems, shading is one of the main limiting factors for the development of plants in the understory, especially C 4 plants. However, successful pasture production in silvopastoral systems can be achieved through proper spatial arrangement. This study provides fundamental information that validates the macauba-grass consortium. For 20 months, during two dry seasons and two rainy seasons, microclimatic and physical variables in an Acrocomia aculeata-Brachiaria decumbens intercropping system were monitored. The spacings of the trees were 5 m × 4 m, 6 m × 4 m, 7 m × 4 m, and 8 m × 4 m and were compared to a traditional pasture. The aboveground biomass in the intercropping system was estimated as well as its ability to assimilate atmospheric CO 2 and store carbon. Macauba palm presence in the intercropping system had a regulatory effect on the microclimatic conditions of the understory, regardless of tree spacing and season. In spacing, wider, the intercropped forage biomass was satisfactory and similar to that in the monocrop pastures. The spacing 7 m × 4 m and 8 m × 4 m improved the understory microclimatic conditions, allowing efficient forage growth and thus offering livestock food and comfort. These values were equivalent to those of traditional silvopastoral systems that use woody plant species. The estimates of aboveground biomass, carbon stock, and CO 2 assimilation in the intercropping system with a spacing of 8 m × 4 m were 1.6 times greater than those of traditional pastures. Therefore, here, we show for the first time that A. aculeata-B. decumbens grass intercropping system is a viable alternative agroforestry practice for tropical regions, since sufficient amounts of fodder are provided alongside beneficial environmental services, such as the efficient sequestration and storage of atmospheric carbon.

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