RESUMO -A influência dos teores de água (8 e 10% b.u.), da embalagem ('pouch' de alumínio flexível e saco de papel multifoliado) e do ambiente de armazenamento (laboratório, com a temperatura variando de 21-29 º C e 50-80% UR e duas condições controladas 18 º C/24%UR e 4 º C/ 60%UR) sobre a qualidade das sementes de maracujá amarelo foram avaliadas neste trabalho. As sementes acondicionadas nas diferentes embalagens foram expostas aos três ambientes para serem avaliadas, bimestralmente, tendo sido determinado: o teor de água, a germinação e o vigor das sementes, pelo teste de envelhecimento acelerado. Os resultados indicaram que as sementes acondicionadas com teor de água de 10% apresentaram uma redução drástica na germinação, quando acondicionadas em embalagem impermeável em condição de laboratório, enquanto o ambiente sob temperatura de 4 º C e 60% UR foi o mais eficiente para preservar a viabilidade das sementes, independente do tipo de embalagem.Termos para indexação: semente, maracujá, germinação, vigor, armazenamento. INFLUENCE OF MOISTURE CONTENT, PACKAGING AND STORAGE ENVIRONMENT ON YELLOW PASSION FRUIT SEED QUALITYABSTRACT -This experiment was designed to verify the influence on yellow passion fruit seed quality of 8 and 10% moisture content (wet basis), package type ( flexible aluminum pouch and paper bag) and the storage environment: laboratory room, temperature varying between 21-29ºC and relative humidity between 50-80%, and two controlled conditions, 18ºC/24%RH and 4ºC/ 60%RH. The seeds placed in the different packaging were stored in the three different environments for bimonthly evaluation. The following determinations were carried out: seed moisture content, germination and the vigor determined by the accelerated aging test. The tests indicated that seeds conditioned with 10% moisture content presented a drastic reduction in germination, when placed in impermeable packaging in laboratory room conditions, while the treatment with temperature of 4ºC and 60% RH showed the best results to preserve the seed viability, regardless of the type of packaging.

Brassinosteroid and substrates in acclimatization of 'Imperial' pineapple. This work aimed to evaluate the effects of different concentrations of a brassinoesteroid analogue (BIOBRAS-16) and two substrates on the growth of micropropagated seedlings of 'Imperial' pineapple. A randomized block design was used in a 2 x 5 x 4 factorial scheme, evaluating five concentrations of BIOBRAS-16 (0; 0.1; 0.3; 0.5 and 1 mg L-1), two types of substrates and four sampling periods (60, 90, 120 and 150 days after planting). The substrates used were Plantmax ® and another obtained from a mix of composting sugar-cane bagasse and filter cake (CC). The seedlings were transplanted to small conic tubes and allocated in a greenhouse equipped with an intermittent mist. The plants cultivated in CC substrate and sprayed with 0.1 mg L-1 of BIOBRAS-16 showed higher growth of shoots with greater numbers of leaves, rosette diameter, leaf width, fresh and dry matter production at 150 days after planting. The plants that were cultivated on CC substrate and sprayed with BIOBRAS-16 at a 0.1 mg L-1 produced 2.8 times more dry matter than the control cultivated in Plantmax ® substrate. The fresh and dry matter of roots were superior in Plantmax ® when compared to CC at late sampling periods.

Plant Ecophysiology was used as a tool to interpret the responses and adaptation of pastures to environmental conditions. The objective of this study was to evaluate ecophysiological parameters in Brachiaria decumbens grown in different grazing systems in the Cerrado's biome in the south state of Maranhão, Brazil. The experiment was conducted in a completely randomized design with nine replications, using a 3×2×3 factorial arrangement consisted of three grazing management systems (silvopastoral, a rotation system with regeneration of native vegetation, and extensive) two seasons (dry and rainy), and three evaluation times along the day. The photochemical efficiency, performance index, and estimation of chlorophyll content were evaluated. According to the results, most of the parameters of the variables evaluated for B. decumbens presented stress conditions, thus compromising their photosynthetic apparatus. B. decumbens presented the best photochemical efficiency and estimated chlorophyll content throughout the day in the silvopastoral system, in both evaluated seasons, therefore, it is a promising species of grass for this system.

Emergência de plântulas e desenvolvimento inicial de mudas de aroeira sob diferentes substratosEmergency of seedlings and initial development of aroeira under different substrates

As sementes da Guazuma ulmifolia apresentam dormência tegumentar, sendo necessária a realização de tratamento térmico para superação de dormência. O objetivo do trabalho foi testar a influência do tratamento térmico e composição de substratos na emergência de plântulas e crescimento inicial de G. ulmifolia. O experimento foi conduzido no Viveiro Florestal Berço da Natureza, pertencente área da Usina Hidroelétrica de Estreito, localizado no município de Estreito-MA, em 2021. Foi preparado primeiro o substrato padrão composto por (terra preta 60%, esterco de galinha 15%, argila 20 %, NPK (10:10:10) 3%, calcário 2%). O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5 x 5 [cinco temperaturas (0, 20, 40, 60 e 80oC) x cinco substratos (S1 – 100% substrato padrão; S2 – 90% substrato padrão + 10% esterco de galinha; S3 – 90% substrato padrão + 10% de fosfato de rocha; S4 – 80% substrato padrão + 20% de fosfato de rocha; S5 – 70% substrato padrão + 10% esterco de galinha + 20% de fosfato de rocha). Aos 40 dias após a semeadura foram avaliadas: emergência, comprimento da parte aérea e sistema radicular, biomassa seca da parte aérea e sistema radicular. A temperatura de 80 ºC associado ao substrato S1 (substrato padrão) é uma combinação eficiente para emergência de plântulas e crescimento inicial de G. ulmifolia.