ABSTRACT The early seedling stage is one of the most vulnerable and critical growth stages in the plant life cycle and determines the final plant stand and yield. Corn hybrids have distinct degrees of drought tolerance, and exploiting this characteristic is important to enhance agricultural production in many tropical regions of the world. Fourteen corn hybrids commonly grown in the central-western region of Brazil, in Cassilândia, Mato Grosso do Sul, were assessed for drought tolerance during the early plant growth stage. Plants were grown in the Plant Ecophysiology Laboratory under non-stressful (control) and stressful (moderate drought) conditions for 28 days. Drought stress was induced with an -0.30 MPa iso-osmotic solution prepared with polyethylene glycol (PEG-6000). The emergence rate, seedling length, and seedling dry matter were measured, and then drought tolerance indexes were calculated. Our results showed that root length is an important morphological trait for plant adaptation to drought stress conditions. Therefore, plant breeding programs should select corn genotypes with longer roots to develop commercial hybrids with superior performance under limited soil water availability. The corn hybrids FS 575 PWU, GNZ 7757 VIP3, LG 36745 PRO4, and MG 545 PWU have greater tolerance to drought stress and are the most suitable genotypes to be grown in conditions of low soil water availability. The AG 8088 PRO2 corn hybrid has greater susceptibility to drought stress and should not be recommended for cultivation in conditions of reduced soil water availability.

ABSTRACT Delays in soybean harvesting can limit seed viability and vigor. In this study, soybean cultivar seeds’ physiological and sanitary quality was evaluated in response to harvest delay. The experimental design used was completely randomized blocks, arranged in a split-plot scheme, with three replicates. The plots were represented by the cultivation of two soybean cultivars (BMX Bônus IPRO and BMX Olimpo IPRO), while the subplots were represented by three harvest times [0, 7, 14 days after the seed’s full maturity (stage R8)]. The following characteristics of the physiological and sanitary quality of the seeds were measured: water content, plant emergence, total dry matter, germination, accelerated aging, electrical conductivity, and seed health. The delay in the soybean harvest affects the seeds’ physiological and sanitary quality. Seeds harvested seven days after full maturity have a higher incidence of Aspergillus flavus and Macrophomina sp. In comparison, seeds harvested 14 days after full maturity have a higher incidence of Phomopsis sp. and Fusarium sp.

ABSTRACT The use of cold plasma is effective in overcoming seed dormancy. However, its effects, both in the long-term and during storage, is still not fully understood. The aim of this study, therefore, was to evaluate the immediate and post-storage effect of atmospheric plasma on the seeds of Pityrocarpa moniliformis in overcoming seed coat dormancy. The seeds were treated with plasma for 0, 1.0, 2.0, 3.0, 4.0 and 5.0 minutes. Following application, 50% of the seeds were stored for two years while the remainder were submitted to immediate analysis. The seeds were evaluated for germination and the germination speed index, in addition to seedling length and dry weight. The experimental design was completely randomised, and included regression analysis. The plasma treatment resulted in an increase in the germination rate and vigour of the seeds, both immediately after exposure and after two years of storage. In particular, the seeds treated for five minutes showed around 39% germination, which was outstanding compared to seeds from other exposure times. Plasma is effective in overcoming seed coat dormancy in seeds of P. moniliformis treated for five minutes and tested immediately. The effect of plasma on the seeds of P. moniliformis after storage was less for all the conditions under test. However effects longterm long term understood study therefore poststorage post 0 10 1 1.0 20 2 2.0 30 3 3.0 40 4 4. 50 5 5. application analysis index weight randomised particular 39 times P test 1. 2. 3.

ABSTRACT Chia (Salvia hispanica L.) seeds have attracted great economic interest for their high levels of linoleic and α-linolenic acids. In Brazil, there is a lack of studies on the agronomic characteristics and physiological quality of chia, necessitating research on germination processes and strategies to enhance yield under field conditions. There are no studies assessing the development of seeds with different coat colors in the presence of fungicides. This study aimed to assess the physiological quality of chia seeds as a function of coat color and fungicide treatment. The experiment followed a completely randomized design with a 2 × 2 factorial arrangement and six replications. For this, seeds were divided into two groups according to coat color (black and white) and subjected or not to treatment with carboxin + thiram. Germination speed index, germination rate, and shoot length were evaluated in plants sown at 0, 90, and 180 days after seed treatment. Germination rate and speed index differed significantly between coat colors, with white seeds having higher vigor than black seeds. Shoot length, however, differed only for seeds sown on the day of treatment, indicating that treated seeds were more vigorous. Salvia L. L αlinolenic α linolenic acids Brazil conditions fungicides replications this thiram 0 90 18 however vigorous 9 1

ABSTRACT Cobalt (Co) and molybdenum (Mo) are essential elements with a fundamental role in biological nitrogen fixation in legumes. Vitamins such as thiamine, despite being required in small quantities, influence plant growth. This study aimed to assess the efficiency of different doses of thiamine applied as seed treatment, combined or not with Co and Mo, in enhancing the development of soybean crops. The experiment was conducted in a greenhouse according to a randomized block design with a 6 × 2 factorial arrangement, comprising six thiamine doses (0, 10, 25, 50, 100, and 200 mg kg-1) in the presence or absence of Co and Mo at the recommended rate of 100 mL ha-1. At 40 days after sowing, plants were analyzed for root length, root dry weight, shoot length, shoot dry weight, nodule number, and nodule dry weight. Principal component analysis showed that combined application of Co and Mo with thiamine was negatively associated with all variables and that the thiamine doses most positively associated with the analyzed variables were 50 and 200 mg kg-1. In treatments containing thiamine alone, there was a linear direct relationship between thiamine dose and nodule dry weight. Root and shoot lengths and dry weights were highest in plants treated with thiamine only at a dose of 122 mg kg-1. Application of Co and Mo combined with thiamine via seed treatment does not promote the development of soybean crops. Thiamine application is a promising treatment to increase shoot length, root dry weight, and nodule dry weight in soybean. (Co (Mo legumes quantities growth crops arrangement 0, 0 (0 10 25 20 kg1 kg 1 kg-1 ha1. ha1 ha 1. ha-1 4 sowing length number 5 kg1. alone 12 ( kg- ha-

ABSTRACT Stress caused by defoliation can compromise the physiological quality of soybean seeds. However, there is evidence that the application of nitrogen (N) can be an alternative to reduce the qualitative losses in seeds caused by defoliating insects. The objective of this study was to evaluate the effectiveness of topdressing N fertilization in improving the physiological quality of soybean seeds from plants subjected to artificial defoliation. The experimental design was a randomized block arranged in a 2×4 factorial scheme with four replicates. The treatments consisted of two levels of defoliation (33 and 66%) and four doses of N (0, 50, 100, and 150 kg ha-1), using urea (45% N), applied two days after defoliation. Artificial defoliation was performed during the R3 stage by removing one (33%) and two leaflets (66%) from each trifoliate leaf under field conditions. At stage R5.1, leaf area was quantified, and after harvesting, germination, emergence, length, total dry mass, electrical conductivity, total protein content, mass of 1000 seeds, and tetrazolium (vigor and viability) tests were carried out. It was concluded that increasing the defoliation from 33 to 66% impaired the physiological quality of soybean seeds. The use of nitrogen fertilization for coverage after defoliation at the beginning of the reproductive phase cannot minimize qualitative losses in seeds.

ABSTRACT Harvest delay can alter the physiological and sanitary quality of sorghum seeds due to the longer exposure time of seeds to adverse environmental conditions in the field. In this study, we investigated the impact of delayed Sorghum sp. harvest on the physiological and sanitary quality of seeds in four hybrids grown in the tropical soil of the Brazilian Cerrado region. Plants from four Sorghum sp. hybrids (IPA SUDAN 4202, BRS 658, BRS 810, and BRS 373) were grown and submitted to four seed harvest periods (0, 7, 14, and 21 days after stage 9 - seed physiological maturity). The treatments were arranged in a completely randomized block design in a 4 × 4 factorial, with four replicates. At each harvest period, the thousand-seed weight, water content, first count of the germination test, germination, seedling emergence, emergence speed index, seedling dry matter, accelerated aging, electrical conductivity, and sanitary quality of seeds were determined. Seeds of higher physiological and sanitary quality of the IPA SUDAN 4202 and BRS 658 sorghum hybrids can be obtained when the harvest is carried out up to 7 days after the physiological maturity stage. However, the delay in seed harvesting at 14 and 21 days after physiological maturity results in a higher incidence of Colletotrichum sp., Curvularia sp., Rhizoctonia sp., and Alternaria sp. on the seeds of these hybrids. Delaying the harvest of sorghum seeds from 7 days after the physiological maturity stage compromises seed vigor and viability and increases the incidence of pathogens.

ABSTRACT This study investigated the effectiveness of using the X-ray technique to assess the viability of papaya seeds. The X-ray images were performed in eight replicates of 25 seeds, placed on transparent acrylic plates on double-sided adhesive tape, previously identified, and then submitted to radiation in X-ray equipment "HP Faxitron". After exposure to X-ray radiation, the seeds were submitted to the germination test in rolls of germitest paper and kept in a germination chamber at 20-30 °C for 30 days. Seedlings were photographed and evaluated as normal seedlings, abnormal and non-germinated seeds. Afterward, the X-ray images and the seedlings from the same seeds were visually compared, and the X-ray images clearly showed seeds with and without internal filling. All abnormal seedlings were full seeds; therefore, X-ray images were not able to separate normal and abnormal. A 100% accuracy was verified by comparing the X-ray images and their respective seedlings, full seeds originated normal or abnormal seedlings, and empty seeds corresponded to non-germinated seeds. Therefore, using X-ray images is a promising technique to identify the viability of papaya seeds. The automated analysis of X-ray images is a simple, fast, and efficient technique to provide information on seed viability and generate parameters related to their germination capacity. Xray X ray 2 doublesided double sided tape identified HP Faxitron. Faxitron . Faxitron" 2030 20 20-3 C 3 days nongerminated non germinated Afterward compared filling therefore 100 Therefore simple fast capacity 203 20- 10 1

ABSTRACT Among the main problems that compromise the development of forest species are water and salt stresses, especially in the early stages of development, when seedlings are more sensitive. Thus, the objective of this study was to evaluate the morphophysiological and biochemical changes in Enterolobium contortisiliquum seedlings subjected to abiotic stresses. The experimental design was randomized complete blocks (RCB), composed of five treatments, with four replicates, and the experimental plot consisted of twenty plants. From the 31st day after sowing, when the seedlings reached approximately 15 cm in height, they began to receive the treatments, which consisted of different levels of electrical conductivity of irrigation water (0.3; 2; 4; 6; 8 dS m-1) for salt stress and periods of water restriction (0; 4; 8; 12 and 16 days without irrigation) for water stress. The traits evaluated were: plant height, root length, stem diameter, number of leaves, leaf area, total dry matter, Dickson quality index, height/shoot dry matter ratio, total soluble sugars, starch, total amino acids and proline. An increase in the electrical conductivity of irrigation water and days without irrigation compromised the development of E. contortisiliquum seedlings, which was intensified from 2 dS m-1 and four days without irrigation for salt and water stresses, respectively. The mechanism of survival of E. contortisiliquum to abiotic stresses involves reduction in the growth and quality of seedlings, with activation of biochemical defense mechanisms of the species. sensitive Thus RCB, RCB , (RCB) treatments replicates plants st sowing 1 height 0.3 03 0 3 (0.3 4 6 m1 m (0 were length diameter leaves area index heightshoot shoot ratio sugars starch proline E m- respectively (RCB 0. (0. (

Abstract: Melon is one of the most consumed cucurbits and commercially significant cucurbits in the world. It is planted predominantly through seedlings, and seed quality is essential in this process. Among the rapid tests used in seed analysis, the pH testing of exudate has shown promise for several cultivated species. Thus, this study aimed to verify the viability of melon (Cucumis melo L.) seeds through the pH testing of exudate. For this, seeds of the hybrids Premier and Supreme (three lots each) were subjected to germination and vigor tests (first germination count, tetrazolium, accelerated aging, emergence speed index, and emergence). The pH testing of exudate was evaluated using phenolphthalein and sodium carbonate solutions. The results indicated the possibility of classifying the lots into three quality levels for both hybrids, similar to most tests used to assess initial quality. Therefore, the pH testing of exudate was effective in determining the viability of lots of melon seeds and can be conducted with a soaking period of 120 minutes at 25 or 30 °C.

Resumo: O meloeiro é uma das cucurbitáceas mais consumidas e de maior interesse comercial do mundo. Seu plantio é realizado predominantemente por meio de mudas, sendo a qualidade das sementes fundamental neste processo. Dentre os testes rápidos utilizados na análise de sementes, o pH do exsudato tem se mostrado promissor para várias espécies cultivadas. Com isso, objetivou-se verificar a viabilidade de sementes de melão (Cucumis melo L.) por meio do teste de pH do exsudato. Para isso, sementes dos híbridos Premier e Supreme (três lotes de cada) foram submetidas aos testes de germinação e vigor (primeira contagem de germinação, tetrazólio, envelhecimento acelerado, índice de velocidade de emergência e emergência). O teste de pH de exsudato foi avaliado com a utilização de soluções de fenolftaleína e carbonato de sódio. Os resultados indicaram que para ambos os híbridos foi possível classificar os lotes em três níveis de qualidade, semelhantes a maioria dos testes utilizados na avaliação da qualidade inicial. Com isso, o teste de pH do exsudato mostrou-se eficaz para determinar a viabilidade de lotes de sementes de melão, podendo ser conduzido com período de embebição de 120 minutos a 25 ou 30 °C.

ABSTRACT The objective was to verify if the primary root emission can be recommended as a vigor test for soybean seeds. For this, five lots of varieties ANTA 82, NA7337 and BRS1074IPRO were evaluated by first count, germination, emergence, emergence speed index and tetrazolium tests. In the root protrusion test at 20, 25 and 30 ºC, two evaluation criteria were adopted: primary root emission precocity index (PREPI) and percentage of seeds that emitted the primary root (PRE). The seeds counted were those with a primary root equal to or greater than 2 mm, every 12 h from the installation of the test until 120 h. The design was completely randomized and means were compared, within each evaluation time, using the Scott-Knott test at 5% probability. Pearson’s linear correlation was performed for PREPI and PRE with emergence. PREPI was not considered efficient. For the PRE, at 20 ºC, there was a correlation at 72 h, for the three varieties. At 25 ºC there was a correlation for a period of 36 h for ANTA 82 and NA7337 and 60 h for BRS1074IPRO. At 30 ºC there was a correlation in the time of 36 h for the three cultivars. Considering that speed in obtaining results is important in vigor tests, it is concluded that primary root emission for 36 h after installing the test at 30 ºC is recommended as a vigor test in the quality control of soybean seeds.

Resumo: Recentemente está crescendo a necessidade de tecnologias não invasivas, rápidas e precisas que possam estimar a qualidade das sementes. Entre essas tecnologias, destaca-se a análise de imagens de raios X para avaliação da morfologia interna das sementes. Assim, o objetivo deste estudo foi avaliar a eficiência do software SARS na análise de radiografias digitais de sementes de braquiária, denominado SARS (Sistema de Análise de Radiografias de Sementes) na avaliação da qualidade física das sementes. Cinco lotes comerciais de sementes de Urochloa decumbens cv. Basilisk foram utilizados. As sementes foram produzidas na safra de 2018/2019. As imagens radiográficas das sementes foram analisadas por meio do SARS, por meio das quais foram obtidas características físicas. As sementes foram submetidas ao teste de germinação, no qual foram mensuradas variáveis relacionadas à qualidade fisiológica. Foi possível observar que as sementes com maior potencial de germinação e vigor apresentaram correlações fortes e significativas com algumas das variáveis físicas obtidas pelo SARS. Assim, a alta correlação do comprimento de plântulas e a densidade relativa das sementes é importante para validar o método de análise de imagens radiográficas de sementes. O SARS mostrou-se uma ferramenta eficiente para análise de radiografias digitais de sementes de braquiária, gerando descritores que dão suporte a análise morfométrica e interna das sementes, que podem ser associados à sua qualidade fisiológica. Os parâmetros físicos obtidos pela técnica têm estreita relação com a germinação e o vigor das sementes.

Abstract: Recently is growing the need for non-invasive, fast, and accurate technologies that can predict seed quality. Between these technologies, X-ray image analysis stand out for evaluation of the internal morphology of the seeds. Thus, the aim of the present study was to evaluate the efficiency of a specialized software for analyzing digital radiographs of Urochloa decumbens seeds called SARS (Sistema de Análise de Radiografias de Sementes - Seed Radiograph Analysis System). Five comercial seed lots of U. decumbens cv. Basilisk were used. The seed lots were produced in the 2018/2019 crop season. Radiographic images of the seeds were analyzed in SARS, through which physical characteristics were obtained. The seeds were then subjected to germination test, in which variables related to the physiological quality were evaluated. It was possible to observe that the seeds with greater germination and vigor showed strong and significant correlations with some of the physical variables obtained using SARS. Thus, high correlation of seedling length and relative seed density is important for validating the seed radiographic image analysis method. SARS proved to be an efficient tool for analyzing digital radiographs of U. decumbens seeds. It can generate descriptors which support morphometric and internal analysis of the seeds. Physical parameters obtained by using the technique have close relationship with the germination and vigor of the seeds.

Resumo: A tecnologia de aplicação do plasma atmosférico consiste em um método rápido e prático, que apresenta potencial de modificação da superfície tegumentar de sementes com dureza tegumentar. O objetivo desta pesquisa foi avaliar o efeito da aplicação do plasma frio atmosférico em sementes de Pityrocarpa moniliformis, verificando suas implicações sobre a impermeabilidade do tegumento, germinação e vigor. As sementes foram submetidas ao plasma por 1,5; 2,0; 3,0; 4,0 e 5,0 minutos, utilizando-se como controle, sementes sem nenhum tratamento. Após a aplicação, determinou-se a molhabilidade do tegumento, curva de embebição e condutividade elétrica da solução de embebição. As sementes também foram submetidas ao teste de germinação, tendo-se, a partir dos seus resultados determinado a viabilidade, mediana, uniformidade e assimetria da germinação. As sementes submetidas ao plasma por 4,0 e 5,0 minutos apresentaram os menores ângulos de contato aparente, 64 e 61°, respectivamente, caracterizando maior molhabilidade do tegumento, entre os tratamentos testados. Maior germinação foi observada nos tratamentos com aplicação do plasma quando comparado com o controle. A tecnologia de aplicação do plasma atmosférico tem potencial para ser utilizada como acelerador da germinação de sementes de P. moniliformis.

Abstract: Atmospheric plasma application technology consists of a fast and practical method, which has the potential to modify the surface of seeds with integumentary hardness. The aim of this research was to evaluate the effect of applying atmospheric cold plasma on Pityrocarpa moniliformis seeds, assessing its implications on the seed coat impermeability, germination and vigor. Cells were subjected to plasma for 1.5, 2.0, 3.0, 4.0 and 5.0 minutes, using seeds without any treatment as a control. After application, the seed coat wettability, imbibition curve and electrical conductivity of the soaking solution were determined. Seeds were also subjected to the germination test, and its results were used to determine viability, median, uniformity and asymmetry of germination. Seeds subjected to plasma for 5.0 and 4.0 minutes showed the lowest apparent contact angles, 64 and 61°, respectively, characterizing greater wettability of the seed coat among the treatments tested. Higher germination was observed in the treatments with plasma application when compared to the control. Atmospheric plasma application technology has the potential to be used as an accelerator of P. moniliformis seed germination.

RESUMO O significativo potencial econômico de Swietenia macrophylla tem causado redução intensa nas populações nativas, colocando em risco sua sobrevivência, exigindo assim, medidas para promover adequada avaliação do estado fisiológico das sementes, visando estabelecimento de um programa de qualidade de produção de mudas. Assim, o objetivo do presente estudo foi avaliar o efeito da temperatura e da luz sobre a germinação de sementes e o crescimento de plântulas de Swietenia macrophylla. O delineamento experimental foi o inteiramente casualizado, com dez tratamentos de quatro réplicas com 50 sementes, e constou de: temperaturas constantes de 23, 29, 35 e 41 °C, com fotoperíodo de 24 e 12 h de luz, e alternadas de 25-35 oC e 30-40 oC, com 12 h de luz. Avaliou-se o teor de água, germinação, índice de velocidade de germinação, diâmetro do coleto, comprimento de raiz e parte aérea, massa seca de raiz e parte aérea de plântulas. Germinação na temperatura de 41 oC é letal para sementes de S. macrophylla. O teste de germinação com temperatura constante de 29 oC sob 24 h de luz favorece o processo germinativo das sementes e o crescimento inicial das plântulas.

ABSTRACT The significant economic potential of Swietenia macrophylla has caused immense reductions in the native populations, jeopardizing their survival. Restoring these populations requires the establishment of quality seedling production, which depends on adequate evaluation of the physiological state of seeds. Thus, the aim of this study was to evaluate the effect of temperature and light on seed germination and seedling growth of S. macrophylla. The experimental design was completely randomized, with ten treatments of four replicates of 50 seeds. Treatments consisted of: constant temperatures of 23, 29, 35 and 41 °C, with photoperiods of 24 and 12 h of light, and alternating temperatures of 25-35 °C and 30-40 °C, with 12 h of light. Water content, germination, germination speed index, stem diameter, root length, shoot length, root dry mass and shoot dry mass of seedlings were evaluated. At 41 oC, S. macrophylla seeds failed to germinate. A constant temperature of 29 oC under 24 h of light favors the germination process of seeds and initial seedling growth.

El revestimiento de semillas de arroz con óxido de zinc microparticulado puede maximizar la absorción de este micronutriente por las plántulas y favorecer el vigor de las semillas en comparación con el sulfato de zinc. Este trabajo tuvo como objetivo evaluar las fuentes y dosis de zinc en la calidad de semillas y en la nutrición de plántulas de arroz. El experimento fue desarrollado en delineamiento completamente al azar con cuatro repeticiones, con un testigo sin aplicación de zinc, cuatro dosis de óxido de zinc (20, 40, 80 y 160 g kg-1 de Zn), y un tratamiento en la forma de sulfato de zinc, 40 g kg-1 de Zn. Se evaluaron los siguientes parámetros: germinación, velocidad de envejecimiento, emergencia de plántulas, índice de velocidad de emergencia, prueba fría de semillas, materia seca y acumulación de zinc en la raíz y parte aérea de las plántulas. La cobertura de semillas con zinc, independientemente de la fuente, mejoró la calidad fisiológica de las semillas y la nutrición de las plántulas de arroz. Las fuentes de zinc no alteraron la germinación; sin embargo, el óxido de zinc proporcionó un mejor vigor de las semillas, con la excepción de la mayor dosis, 160 g kg-1. El aumento en la dosis de óxido de zinc aumentó la acumulación de ese nutriente en la materia seca de las plántulas de arroz. El recubrimiento con zinc en semillas de arroz en forma de micropartículas, dependiendo de la dosis, puede maximizar el vigor de las semillas y aumentar la concentración de este micronutriente en las plántulas en comparación con el sulfato de zinc, que es la fuente tradicional utilizada por los productores.

Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg-1), and a control treatment of zinc in the form of sulfate (40 g kg-1). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition. Zinc sources did not affect germination; however, the oxide form induced better seed vigor, except for the highest dose (160 g kg-1). Increasing doses of zinc oxide augmented the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize seed vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, the traditional source.