Na região Sul do país as fruteiras têm papel importante, pois podem servir para exploração econômica. Destacando-se a família Myrtaceae, com fruteiras como araçazeiro. Porém, pouco se conhece sobre a espécie, tornando-se necessários mais estudos principalmente quanto à propagação para futura inserção no sistema de produção agrícola da região Sudoeste do Paraná ou para abastecer o mercado que carece desses produtos. Com isso, objetivou-se com este trabalho avaliar o crescimento e desenvolvimento de mudas dos araçazeiros amarelo e vermelho em diferentes substratos com aplicação exógena de giberelina. O experimento foi conduzido na Universidade Tecnológica Federal do Paraná -Câmpus Dois Vizinhos em casa de vegetação. O delineamento experimental utilizado foi inteiramente casualizado, no fatorial 3x4 (substrato, concentração de GA 3 ), com quatro repetições de 20 plantas por unidade experimental. Foram analisadas variáveis destrutíveis e não destrutíveis de crescimento e o índice de qualidade de mudas de Dickson. Os dados foram submetidos a análise de variância, teste de Duncan e análise de regressão, utilizando o aplicativo computacional estatístico Sanest®. As concentrações de GA 3 e os tipos de substratos influenciaram o desenvolvimento de mudas de araçazeiros. O uso do substrato (S3) associado ao fitoregulador giberelina é recomendado para a produção de mudas de araçazeiro amarelo e vermelho.

Matriconditioning is a technique that aims to standardize and accelerate the germination of seeds and the emergence of plantlets. The objective of the study is to evaluate the effect of that methodology under the physiological performance of amaranth seeds. The experiment used two lots of seeds at the Universidade Tecnológica Federal do Paraná (UTFPR), Campus Dois Vizinhos (Parana State). Plastic boxes of the Gerbox type were the matriconditioning environment, containing 55.5 g of sterile vermiculite moisturized with distilled water at 100% of the retention capacity. Plastic boxes were placed in a germination chamber at ten degrees Celcius. Four repetitions of 100 seeds had their weight measured at 0, 2, 4, 8, 16, and 32 h after the procedure started to obtain the curve of imbibition. The following tests were performed after each period: Germination test, first germination count; length and dry mass of plantlets; emergence speed index, and accumulated emergence tests. Amaranth seeds achieve phase II of germination around 8 h of imbibition by matriconditioning. The effect of matriconditioning in the physiological performance of amaranth seeds varies as a function of the used lot.

Solid matrix priming (matriconditioning) permits slow seed hydration, and germination and emergence period reduction. In general, seeds need to be soaked to start their germination process. The objective of this study was to evaluate the effect of the matriconditioning under the imbibition curve and the physiological performance of two lots of chia seeds with different qualities. The study was performed with chia seeds harvested by small-scale farmers. To estimate the imbibition curve, seeds from both lots were started in the imbibition process on a stainless-steel screen placed in plastic boxes, containing 55.5 grams of sterilized vermiculite and moisturized with distilled water at 100% of their retention capability. The imbibition curve weights were made 0, 2, 4, 8, 16, and 32 hours after the process had started. Simultaneously, in each evaluation period, seeds were submitted to the following tests: germination, first count of germination, plantlet shoot, root and total lengths, emergence velocity index and average time, and accumulated emergence. A completely randomized experimental design was used. It was possible to conclude that the beginning of phase II of germination in matriconditioned seeds varies in function of the chia seeds' lot quality. The matriconditioning contributes to the physiological performance, increasing and accelerating plantlets' emergence.

Ornamental species, especially those involving the use of seedlings in trays to serve residential gardens, need to be produced quickly for commercialization, which requires studies that provide such a condition. The present work aimed to evaluate the effect of light intensity and exogenous application of gibberellin on seedlings of four ornamental species (Calendula officinalis, Gypsophila elegans, Solenostemon scutellarioides and Viola wittrockiana). The experiment was carried out at the Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos. The seeds were sown in trays containing substrate composed of a mixture of humic Distroferric Red Latosol: medium texture sand: commercial substrate, in the volumetric proportion of 2:1:1, respectively. The trays were kept in shading environments, using black screens with 35%, 50% and 80% shading intensity, red with 35% shading, in addition to full sun. After 30 days of emergence, gibberellic acid solution was applied to the seedlings at concentrations of 0 mg L-1 and 300 mg L-1. Emergence, emergence speed index, mean emergence time, total length, shoot and roots, number of leaves, leaf area, root volume density, shoot, root and total dry matter were evaluated. For each environmental condition of cultivation, the values of temperature and air humidity and light intensity were obtained. The use of gibberellic acid proved to be beneficial for Viola wittrockiana and Solenostemon scutellarioides. The shading environments, regardless of color and light intensity, were more favorable for the formation of seedlings of these four ornamental species.

Na flora arbórea brasileira destaca-se o araçazeiro, fruteira nativa da família Myrtaceae com grande potencial de produção. Na propagação predomina o uso de sementes, pois apresenta grande homogeneidade no padrão das mudas obtidas, relacionado a apomixia e curto período juvenil. Entretanto, é necessário adotar técnicas de armazenamento que garantam a viabilidade por maior período de tempo. Neste sentido, o trabalhou objetivou avaliar formas de conservação da viabilidade de sementes de araçazeiro amarelo cv. Ya-Cy por período de 12 meses. Adotou-se delineamento experimental inteiramente casualizado (DIC), em bifatorial 12 X 5 (tempo x formas de armazenamento), com quatro repetições de 100 sementes. Foram avaliadas a porcentagem de germinação (G %), índice de velocidade de germinação (IVG) e tempo médio de germinação (TMG). Recomendou-se o uso de recipientes como eppendorf® ou material tetrapak® para armazenar sementes de araçazeiro Ya-Cy, visando conservar sua viabilidade e vigor até os 330 dias. Utilização de gordura animal não foi recomendada para armazenamento de sementes de araçazeiro Ya-Cy. Palavras-chave: Araça amarelo; Psidium cattleyanum Sabine; viabilidade de sementes; conservação de sementes. FORMS OF STORAGE OF ARAÇAZEIRO SEEDS

Myrcianthes pungens is a tree fruit native to Brazil, unknown to a large part of the population, with fruit consumed only locally. In October 2022, at the experimental area at Universidade Tecnológica Federal do Paraná (UTFPR) in the Dois Vizinhos city, Paraná State, Brazil, symptoms of the disease were observed on mature leaves and fruits of 17 trees. Fungal fructifications were observed in the form of bright yellow uredinia containing a large mass of urediniospores on the surface and on the leaves and fruits that resembled the structures typical of a Myrtaceae rust pathogen. Leaves colonized by the fungus showed deformations, turning dark and rapidly causing senescence. In the orchard, the fungus affected 80% of the trees, with a severity of 40 to 45%. Diseased fruits (10) and leaves (10) (from each tree) were collected from 17 trees from different positions in the orchard. The observed structures (optical microscope) were hyaline and globose urediniospores (n = 30) which had pointed echinulate ornaments throughout their surface (Cummins & Hiratsuka, 2003), (n = 30, 14.84 μm × 21.1 μm). These characteristics were similar to the morphological characteristics of the genus Austropuccinia previously described by Young et al. (2019). A strain was selected as a representative for molecular characterization and pathogenicity tests (accession no. APM001). For molecular identification, the internal transcribed spacer (ITS) region (Kroop et al., 1995), b-tubulin (TUB2), and translation elongation factor 1-alpha (TEF) (Machado et al., 2015) were amplified by PCR and sequenced. The sequences were deposited in GenBank (accession nos. ITS: OQ442638, TUB2: OQ506543, and TEF: OQ506542). Phylogenetic analyses using Bayesian inference grouped the isolate with the type species of Austropuccinia psidii with a high posterior probability (1.0). Pathogenicity tests used conidial suspensions (1x105urediniospores/ml). Four branches containing twenty leaves and two young asymptomatic fruits were individually inoculated with 1.5 mL of urediniospore suspension using a bottle with a spray nozzle cap. The branches were protected with perforated transparent plastic bags moistened with distilled water and incubated at room temperature (18 ºC to 25 ºC). Three replicates (pathogen and control) spread on different trees in the orchard were used in this experiment. After seven days, symptoms of rust appeared on the leaves and on the tenth day of the fruits, with morphological characteristics similar to those previously reported. Control branches showed no fungal growth. The inoculation test was repeated, confirming the symptoms. This is the first report of the incidence of rust caused by A. psidii on leaves and fruits of M. pungens in Paraná State. The importance of the disease is due to the high percentage of fruit loss due to rapid rot and drop caused by the pathogen attack.