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The objective was to evaluate the initial performance of the bean genotypes grown in lowland soil in the State of Rio Grande do Sul. The experiment was conducted in the 2015/2016 agricultural harvest, in a chapel greenhouse, arranged in the North-South direction, covered with polycarbonate and equipped with temperature controllers, located under the coordinates 31º 52'00 " South latitude and 52º 21'00 "west longitude with an altitude of 13 meters, this structure is located at the Federal University of Pelotas. The experiment was carried out in a randomized block design with five bean genotypes (IPR Tuiuiú, Carioca, Mouro, BRS Guabiju and BRS Embaixador) and four initial collection periods (9 DAS, 13 DAS, 17 DAS and 21 DAS), arranged in five replicates. The different bean genotypes reveal dissimilar initial growth rates in the face of the adversities imposed by lowland soils. The BRS Guabiju genotype is superior to the others for initial growth and is more acclimatized to the soils of the extreme south of Rio Grande do Sul.

The aim of this study was to assess the impact of nitrogen doses on the yield of two barley cultivars, namely BRS Brau and BRS Cauê, cultivated in various growing environments in Southern Brazil. The research was conducted during the 2017 harvest season in Alegrete and Pelotas, RS, Brazil. A randomized block design with a factorial scheme of 2 x 2 x 4 (growing environments x barley cultivars x nitrogen doses) was employed, with four replications. Various parameters were evaluated, including plant height, number of tillers per plant, number of ears per square meter, number of seeds per plant, thousand seeds weight (TSW), and yield. The results indicated that the two barley cultivars responded differently to the growing environments and nitrogen doses. In Pelotas, BRS Brau exhibited superior performance in terms of plant height and TSW, while BRS Cauê showed a higher number of seeds per plant and seed yield. Furthermore, the combination of the Pelotas growing environment and a nitrogen dose of 200 kg ha-1 resulted in optimized growth and yield of barley seeds.

O objetivo deste trabalho foi avaliar o desempenho fisiológico e bioquímico de sementes de trigo produzidas em diferentes estados do Brasil. Este estudo foi conduzido em delineamento de blocos casualizados com 11 tratamentos dispostos em três repetições. A análise de variância revelou significância para Germinação (G), Velocidade de germinação (GS), Envelhecimento acelerado (AA), Comprimento da raiz (RL), Velocidade de emergência (ES), Comprimento da plântula (SL), Massa de mil sementes (TSM), Peso hectolitro (HW), Área foliar (LA), Teor de proteína (PTN), lipídios (LIP), fibra bruta (FB), cinzas (CNZ), amido (AMD), carboidratos totais (CT) e carboidratos não fibrosos (CNF). As sementes da cultivar TBIO Audaz oriundas de Brasília apresentaram qualidade superior, com maior vigor no teste de envelhecimento acelerado, comprimento da parte aérea e velocidade de emergência, sendo também a cultivar com maior teor de amido. Dentre os materiais estudados, verifica-se que independente da cultivar e local de produção das sementes de trigo existe uma associação positiva entre os atributos bioquímicos e físicos que influenciam na qualidade fisiológica do trigo, destacando-se o teor de amido, fibra e material mineral, bem como - massa de mil sementes, germinação, vigor e comprimento de plântulas.

A nutrição é um fator limitante na produção e qualidade de sementes de cevada. Nesse sentido, é necessário um adequado suprimento de nitrogênio para a obtenção de produtividade e qualidade fisiológica de sementes. Assim, o objetivo desse trabalho foi avaliar as respostas de duas cultivares de cevada, BRS Brau e BRS Cauê, em diferentes doses de adubação nitrogenada, inferindo sobre a produtividade e a qualidade fisiológica nas diferentes situações. O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 2x4, (duas cultivares X quatro doses de nitrogênio) e os tratamentos consistiram na combinação de duas cultivares (BRS Cauê e BRS Brau) e quatro doses de nitrogênio, totalizando oito tratamentos. O experimento foi conduzido no município de Capão do Leão e a coleta de dados para avaliação da resposta das plantas às doses de nitrogênio quanto ao rendimento e qualidade fisiológica de sementes de cevada, foram analisados no Laboratório de Análise de Sementes do Programa de Pós-Graduação em Ciência e Tecnologia de Sementes. As cultivares BRS Brau e BRS Cauê apresentaram diferentes exigências de nitrogênio para as variáveis altura de planta, rendimento por planta e rendimento total. Em relação à qualidade fisiológica de sementes, a utilização de diferentes doses de nitrogênio não afetou significativamente a germinação e o vigor das sementes. Porém, para as expressões isoenzimáticas, as diferentes doses de adubação nitrogenada influenciaram as plântulas de cevada. Palavras-chave: Hordeum vulgare; adubação nitrogenada; qualidade fisiológica; expressões isoenzimáticas.

ABSTRACT The objective of this study was to evaluate the performance of wheat plant grown from seeds with different vigor levels. The experimental design was randomized blocks in a 3 x 3 factorial design (cultivar x vigor level) with four replications. The wheat cultivars were Tbio Toruk, Tbio Mestre and Tbio Iguaçu. The classification of vigor levels was high, medium and low, determined by several vigor procedures. The following evaluations were performed: plant height, number of spikelets in the main tiller, number of seeds in the main tiller, seed mass in the main tiller, number of fertile tillers, number of seeds in tillers, seed mass in tillers, number of plants.m-2, number of spikes.m-2, and grain yield per hectare. The use of high vigor seeds provides a greater number of wheat plants and spikes per area. Grain yield is affected significantly by seed vigor level: there is an increase of up to 11% by using high vigor seeds compared to low vigor seeds.

This work aimed to evaluate the chemical composition and the initial growth of soybean seedlings originated from seeds produced under influence of soil flooding in the crop reproductive period. The experimental design was totally randomized, organized in factorial scheme being two soybean cultivars x three soil-flooding periods, and the traits were disposed in four repetitions. When submitting soybean plants to flooding at R5 stage, the mass of thousand seeds was reduced independently of the cultivar. The shoot growth and length, shoot dry matter, and roots dry matter characters were negatively influenced due to soil flooding in R5 growth stage. The oxygen deficiency can cause alteration in roots and shoot protein concentration on soybeans seedlings. The aminoacids concentration was stimulated in roots and shoot of seedlings originated from seeds produced under hypoxia conditions.

ABSTRACT: The aim of this work was to evaluate whether there is any influence of temporary soil flooding on the agronomic performance and yield of wheat varieties. The experimental design was completely random blocks, in an 11x2 factorial scheme (eleven varieties and two soil water conditions), with four replications. Stress was imposed in the stage prior to plant anthesis. The assessments were made in two seasons (2016/2017) in relation to the number of spikelets in the main ear, number of seeds in the main ear, mass of seeds in the main ear, number of seeds in the tiller ear, mass of seeds in the tiller ear and yield in the useful area. The physical attributes number of seeds, seed mass and wheat seed yield, according to variety and agricultural year, are negatively affected by the temporary flooding (12 days) of the soil. There is influence of temporary soil flooding on the agronomic performance and yield of wheat varieties. The varieties TBio Toruk, TBio Sinuelo, TBio Sintonia, and CD151 are superior in soil flooding condition for the number of spikelets, number of seeds end for the seed mass attribute. In the soil at field capacity, the seeds produced have higher yield compared to those produced under flooding period, reaching about 309.2 Kg more for the variety TBio Sinuelo, 262 Kg for TBio Toruk and 114 Kg in CD1303.

O trabalho objetivou avaliar o efeito de diferentes épocas de semeadura e densidades de cultivo na expressão de caracteres agronômicos da soja. O delineamento usado foi inteiramente ao acaso em esquema fatorial 2x5 (duas épocas de semeadura e cinco densidades de cultivo), em quatro repetições. A semeadura na primeira época foi realizada em 15 de novembro de 2018 e a segunda em 14 de dezembro de 2018. As densidades de cultivo foram de 160, 200, 240, 280 e 320 mil plantas por hectare. Foram avaliados altura de plantas, altura de inserção de primeiro legume, diâmetro de haste, número de ramificações, número de legumes, número de sementes, número de legumes na metade inferior e superior de plantas, massa de sementes na haste principal e nas ramificações, rendimento e massa de mil sementes. As densidades de semeadura não afetaram o rendimento de sementes, semeadura na primeira época favoreceu maior rendimento de sementes e maior massa de mil sementes. Em menores densidades de cultivo ocorreu maior ramificação das plantas e maior número de legumes por planta evidenciando a plasticidade fenotípica. O aumento da densidade de cultivos favorece maior proporção de sementes na haste principal e na metade superior das plantas.

This work aimed to evaluate the effect of nitrogen dose management on the growth responses and physiological performance of barley seeds. Two barley cultivars (BRS Brau and BRS Cauê) and four nitrogen doses were used. The experimental design consisted of randomized blocks in a 2 X 4 factorial scheme (cultivars BRS Brau and BRS Cauê x nitrogen doses 120, 150, 180, and 210 kg ha-1). Successive collections of primary data were performed every fourteen days for growth analysis. The analyzed variables were total dry matter, dry matter production and relative growth rate, assimilated partition, and seed electrical conductivity. Increasing nitrogen doses caused a temporal-quantitative difference in growth, partition, and the accelerated aging test of barley seeds. The 150 kg ha-1 N dose resulted in total dry matter over time (Wt) superiority for both evaluated cultivars. The variable dry matter production rate achieved an increase with the 150 kg ha-1 N dose at 70 days after emergence (DAE) for BRS Brau and at 56 DAE for BRS Cauê supporting Wt. The 180 and 150 kg ha-1 N doses increased the relative growth rate for BRS Brau and BRS Cauê.

Abstract: The quality of the seeds and the occurrence of stresses are decisive for the development of the crops. Thus, the work aimed to verify the effect of seed vigor on growth and dry weight partition of wheat plants subjected to water stress. For growth evaluation, the experimental design was completely randomized, in a 2 x 2 x 8 factorial scheme (vigor level x water regime x collection time), with four replications. To evaluate the yield of the seeds, the design was completely randomized, in a 2 x 2 factorial scheme (level of vigor x water regime), with four replications. Total dry weight, dry weight production rate, relative growth rate, leaf area ratio, leaf area, solar energy conversion efficiency, dry weight partition and harvest index were evaluated. Total dry weight production, dry weight production rate, leaf area, leaf weight ratio, solar energy conversion efficiency and yield were higher for plants from highly vigorous seeds under field capacity. The yield was higher for plants with high vigor compared to those with low vigor in field capacity.

O presente trabalho teve como objetivo avaliar a o desempenho de cultivares de feijão submetidas ao déficit hídrico no desenvolvimento inicial das plantas. O experimento foi conduzido na Universidade Federal de Pelotas. As sementes utilizadas foram das cultivares BRS Esteio e IPR Tuiuiú, ambas cultivares do grupo preto. A restrição hídrica foi imposta utilizando PEG-6000 como redutor de potencial osmótico para realizar o teste de germinação. No décimo dia de germinação foram coletadas as plântulas para a avaliação dos seguintes testes: teores de prolina, peróxido de hidrogênio, peroxidação lipídica e enzimas antioxidante que foram avaliadas através da atividade específica das enzimas superóxido dismutase (SOD), catalase (CAT) e ascorbato peroxidase (APX). O delineamento utilizado foi de inteiramente casualizado, no esquema fatorial duas cultivares por quatro potenciais osmóticos. Os dados foram submetidos à análise de variância e os valores de F quando significativos foram comparados pelo teste de Tukey a 5% de probabilidade. Os resultados demonstram que a restrição hídrica, conforme o potencial osmótico, afeta de forma distinta a atividade das enzimas CAT, SOD, APX. O que pode resultar em plantas menos adaptadas ao estresse hídrico.

O presente trabalho objetivou analisar a correlação entre variáveis de crescimentoe caracteres agronômicos de tomateiro. O delineamento experimental foi de blocos ao acaso, com oito repetições. Os tratamentos foram compostos por plantas de tomateiro enxertadas e não enxertadas. Aos 112 dias após o transplante as plantas foram coletadas e separadas em órgãos (frutos, folhas, caule e raiz) para ser avaliado o número de folhas, número de frutos, área foliar, clorofila, eficiência na conversão de energia solar, massa seca de frutos, produtividade comercial, pH, sólidos solúveis totais, carotenóides e compostos fenólicos. Plantas enxertadas apresentaram maiores teores de clorofila. Para as variáveis referentes às correlações, foram encontrados fortes correlações entre a área foliar, o teor de clorofila e a massa seca de frutos e total. Enquanto que, os teores de carotenóides e fenóis totais se correlacionaram positivamente com a área foliar e o teor de clorofila.

O objetivo deste estudo foi avaliar os componentes de rendimento e de qualidade fisiológica de sementes de soja cultivadas com aplicação de diferentes doses e épocas de aplicação de nitrogênio. O delineamento inteiramente casualizado, em esquema fatorial 4x2 (quatro doses de nitrogênio e duas épocas de aplicação), com quatro repetições. A aplicação de nitrogênio foi feita na forma de uréia (45% de N), nas doses de 0, 25, 50 e 75 kg N ha- 1 durante a semeadura e no estádio R4 da cultura. Foi avaliado o número de vagens por planta, o número de sementes por planta, a massa de mil sementes, primeira contagem de germinação, porcentagem de germinação, massa seca de parte aérea e raiz. A aplicação de nitrogênio influenciou positivamente nos parâmetros de rendimento da soja na dose de 75 kg N ha-1 durante o enchimento de grãos. Durante a semeadura, a dose de 25 kg N ha-1 resultou em maiores médias da massa seca de parte aérea, 50 kg N ha-1 incrementou a massa de mil grãos e massa seca de raiz e a aplicação de 75 kg N ha-1 na semeadura durante a primeira safra obteve resultados positivos para a primeira contagem de germinação e germinação. Para os resultados da segunda safra, a aplicação de 50 kg N ha-1 em semeadura proporcionou incremento da primeira contagem de germinação.

Abstract: The objective of this work was to evaluate the adaptability and multi-trait stability of wheat (Triticum aestivum) genotypes according to the phenotypic index of seed vigor (PIV). Thirty wheat genotypes were grown in seven environments in the state of Rio Grande do Sul, Brazil, during one crop season. In each environment, a randomized complete block design with three replicates was used. The PIV was elaborated from the following traits: first germination count, germination percentage, accelerated aging, and electrical conductivity. The evaluated phenotypic index makes it possible to define macroenvironments for the production of wheat seeds with high physiological potential and to understand the implications of the genotype x environment interaction. The phenotypic index of seed vigor is effective to rank genotypes considering multi-trait selection related to the vigor of wheat seeds produced in Southern Brazil.

A semeadura em condições ambientais desfavoráveis tem se intensificado nos últimos anos, enquanto, a utilização do tratamento de sementes com bioestimulantes tem aumentado de forma marcante. Este trabalho objetivou avaliar o desempenho fisiológico de sementes e a expressão isoenzimática de sementes de arroz de sequeiro tratadas com bioestimulante e submetidas à restrição hídrica. Os tratamentos consistiram em sementes sem tratamento (dose zero) e tratadas com bioestimulante (dose recomendada). O déficit hídrico foi estabelecido pelos potenciais hídricos 0,0; -0,20; -0,40; -0,60; -0,80 e -1,0 MPa. Foram avaliados a germinação e o índice de velocidade de germinação, comprimento e massa seca de parte área e de raiz, a expressão das isoenzimas peroxidase, malato-desidrogenase, glutamato oxalacetato transaminase e esterase. A germinação e o índice de velocidade de germinação, o comprimento e a massa seca de parte aérea e de raiz foram reduzidos ao diminuir o potencial hídrico. Potenciais hídricos inferiores a -0,4 MPa reduzem drasticamente a germinação, o vigor e a expressão isoenzimática de plântulas de arroz de sequeiro. O tratamento de sementes com bioestimulante favorece o desempenho de sementes e plântulas de arroz de sequeiro sob restrição hídrica.

Wheat is one of the most cultivated cereals worldwide. Some wheat genotypes may be used for dual purposes that is, in the production of animal fodder and grains. The objective of this study was to compare the growth, partitioning of assimilates, and seed vigor expression of dual-purpose wheat cultivars originating from seeds produced by plants subjected to different cutting management systems. Dual-purpose wheat seeds in the vegetative period were used for this study; these were obtained from the cultivar BRS Umbu produced by plants subjected to different cutting management systems. The experimental design was completely randomized in a factorial scheme, with four replications. The treatments comprised a combination of four seed production systems (one, two, and three cuts) and eight planting seasons (10, 20, 30, 40, 50, 60, 70, and 80 days after emergence [DAE]). Total dry-mass, dry-mass production rate, relative growth rate, net assimilation rate, leaf area index, solar energy conversion efficiency, dry-mass partitioning, seedling emergence in the field, and emergence speed index were evaluated. Data regarding seedling emergence and emergence speed index were adjusted by orthogonal polynomials. Primary growth data were evaluated from the simple logistic equation. From 60 DAE, an inversion of the values of total dry-mass was observed, and the maximum values were observed in plants from seeds produced without cutting management. The highest dry-mass production rates were noted for plants produced by seeds of plants not subjected to cutting management. The highest relative growth rates were noted among plants originating from seeds produced by plants subjected to three- and two-cut treatments. The net assimilation rate was higher in plants originating from seeds produced from plants subjected to cutting management systems. The highest values of emergence were observed for seeds obtained from the three-cut treatment. Similarly, an increase in the values of emergence speed index was observed in seeds from plants subjected to one-cut treatment. Dual-purpose wheat cultivars originating from seeds produced in the absence of cutting management presented higher total dry-mass, dry-mass production rate, and relative growth rate. The net assimilation rate was higher in plants from seeds produced with cutting management systems. Plants produced from seeds subjected to the three-cut production management resulted in more vigorous seeds.

The aims of this study are to provide a comparative analysis of the growth and the expression of seed vigor from wheat plants subjected to periods of waterlogging during the development period. The treatments consisted of different combinations of soil waterlogging: T1 = no waterlogging; T2 = two waterlogging periods, at stages Z25 and Z45; and T3 = three waterlogging periods, at stages Z25, Z45 and Z75. Plants were collected at regular intervals after emergence until the end of the cycle: 14, 28, 42, 56, 70, 84, 98 and 112 days after emergence (DAE). Dry mass and leaf area of samples were determined. From the primary data, the analysis of growth was applied, and the total dry mass, dry matter production, relative growth and net assimilation rates, leaf area, leaf area ratio, leaf mass ratio and specific leaf area were calculated. Seedling emergence, seedling emergence rate index and dry mass of seedling shoots and roots were also evaluated. Wheat plants grown in conditions of field capacity demonstrated better performance compared to those subjected to three periods of soil waterlogging, with higher total dry mass and net assimilation rates. Seedling emergence and seedling emergence rate index did not differ between treatments. However, soil waterlogging for two or three periods resulted in a reduction in the dry matter of roots and shoots of wheat seedlings. The growth of wheat plants was found to be negatively affected by soil waterlogging. The expression of seed vigor from plants not exposed to soil waterlogging was similar to that of plant seeds subjected to soil waterlogging, although seedling growth was affected negatively by waterlogging conditions.

The grafting technique favors cultivation tomato under conditions environment adverse, being the effects on the physiology of scarce plants. Thus, this study aimed to evaluate the growth and solar energy conversion efficiency in grafted tomato and not grafted in greenhouse. The grafting was performed by grafting of cleft and the treatments consisted of tomato plants grafted on hybrid Kaguemusha® and not grafted. The samples for growth analysis were performed at intervals of fourteen days after transplanting (DAT) by the end of the crop cycle. At each harvest, plants were separated into organs, being determined to total dry matter (Wt), rates of dry matter production (Ct) and relative growth (Rw), net assimilation (Ea), leaf area index (L), growth rate, leaf area (Ca), relative growth of leaf area (Ra), leaf area ratio (Fa), leaf weight (Fw), specific leaf area (Sa), conversion efficiency solar energy (?) and assimilation rate of fruit (Efr). From the analysis of data growth, the plants grafted on the hybrid Kaguemusha® had higher Wt, Ct, Rw, Ea and ? compared to non-grafted that showed a high Fa and Fw. Therefore, the stress caused by grafting did not affect the growth at the end of the development cycle of tomato plants, being important feature to keep the crop yield

This study aimed to evaluate the growth, assimilate partitioning and seed vigor expression of rye seeds subjected to waterlogging during development. The experimental design was completely randomized with six replications and three treatments. The treatments involved different waterlogging periods: a) no waterlogging; b) single waterlogging of three days; and c) two soil waterlogging periods of three days. The plants were collected at regular intervals of 14 days after emergence until the end of the growth cycle, measuring the dry matter accumulation and the leaf area for growth analysis and dry matter partition between the organs and number of flowers. The other calculated indices included the harvest index and relative seedling emergence rate originating from the seeds of plants that were maintained at field capacity and under the effect of soil waterlogging. Rye plants that were not subjected to waterlogging had a higher dry matter, dry matter production rates and harvest index compared to the plants under the effect of two soil waterlogging periods. Plants under the effect of two waterlogging periods showed drastic alterations in their growth rates and assimilate partitioning during development, and seed vigor expression was negatively affected when the plants were subjected to soil waterlogging.

The work was conducted to evaluate the effect of different Philodendron bipinnatifidum Schott. extract concentrations on the physiology and enzymatic metabolism of lettuce seeds and seedlings. The treatments extracts of mature leaves at concentrations of 0, 6, 12, 25 and 50%. Were evaluated the germination, first count germination, speed and germination speed index, length of shoot and primary root, seedling total dry mass, electrical conductivity, chlorophyll content, activity of the enzymes ?-amilase, superoxide dismutase, catalase and ascorbarto peroxidase, lipid peroxidation, hydrogen peroxide content and seedling emergence, length of shoot and total dry mass of emerged seedlings. There was a reduction of germination, germination speed index and total dry mass by increasing the concentration of the extract. While the content of hydrogen peroxide, lipid peroxidation and activity of superoxide dismutase, catalase and peroxidase ascorbarto increased with concentration. The increasing of concentration the leaf extracts of the P. bipinnatifidum negatively affects the activity of the enzyme ?-amylase and causes increase in the activity of antioxidant enzymes, affecting the physiologic performance and growth of lettuce seedlings.

The work was conducted in greenhouse and aimed to analyze the growth and partitioning of assimilates in Physalis peruviana subjected in intervals of leaf fertilization. The plants were collected at regular intervals of fourteen days after transplantation until the end of the cycle and determined the dry mass and leaf area. From the primary data analysis was applied to growth analysis and calculated the total dry matter production (Wt), rates of dry matter production (Ct), relative growth (Rw), net assimilation (Ea), leaf area index (L), relative growth of leaf area (Fa) and ratios of leaf area and leaf mass (Fw), specific leaf area (Sa) and dry matter partitioning between organs. Plants of Physalis peruviana subjected to leaf fertilization biweekly reached higher Wt, Ct, number of fruits and similar dry mass of fruits (Wfr) of plants subjected to foliar weekly application and higher Wfr compared to plants without application leaf of fertilization. Thus, the application of leaf fertilization provided benefits of growth and the partition of assimilates in Physalis peruviana plants. O trabalho foi conduzido em casa de vegetação e objetivou analisar o crescimento e a partição de assimilados em Physalis peruviana submetida a intervalos de adubação foliar. As plantas foram coletadas a intervalos regulares de quatorze dias após o transplante até o final do ciclo e foram determinados a massa seca e a área foliar. A partir dos dados primários foi aplicada a análise de crescimento, sendo calculados a massa seca total (Wt), taxas de produção de matéria seca (Ct), crescimento relativo (Rw) e assimilatória liquída (Ea), índice de área foliar (L), razões de área foliar (Fa) e massa foliar (Fw), área foliar específica (Sa), partição de matéria seca entre órgãos e o número de frutos. Plantas de Physalis peruviana submetidas à adubação foliar quinzenal atingiram maior Wt, Ct, superior número de frutos e semelhante matéria seca de frutos (Wfr) a plantas submetidas à aplicação de adubação foliar semanal e superior Wfr em relação a plantas sem adubação foliar. Desse modo, a aplicação de adubação foliar proporcionou benefícios no crescimento e na partição de assimilados em plantas de Physalis peruviana.

This work aimed to evaluate the effect that different intensities of light have on the physiological attributes of red rice seeds and seedlings. Before and after emergence, seedlings were exposed to light levels of 35%; 65% and 100% in a greenhouse. We evaluated shoots and roots, in terms of length and dry mass, as well as leaf area and content of chlorophyll (a,b and total). In leaves and roots, we quantified the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (POX). We determined the leaf area ratio (F A), leaf mass ratio (F W), specific leaf area (S A), and shoot/root ratio (P W). At higher light intensities, shoot length decreased, whereas root length, dry mass and number of tillers increased. Leaf area was greatest in seedlings exposed to a 65% light level. The F A, F W, S A and P W were lowest at a light intensity of 100%. Differences in light intensity had qualitative and quantitative effects on chlorophyll contents. The activity of SOD and CAT was higher at lower light levels, whereas the inverse was true for APX and POX activity. Extremes of light availability alter the activity of antioxidant enzymes, negatively affecting the initial growth characteristics and photosynthetic pigments of red rice seedlings.

The study aimed to analyze the effect of seed treatment with micronutrients on the growth of rainfed rice plants. Treatments consisted in the absence of micronutrient application, single applications or a combination of five micronutrients applied to seeds: compound Zinc + Molybdenum (Mo 2.3, Zn 3.5 % w/v) in a dose of 2 mL kg-1 seed; Copper + Molybdenum + Zinc + Manganese (6.7 Cu, 3.2 Mo, 15 Zn; 9.4% Mn w/v) at a dose of 3 mL kg-1 seed; Zinc (100% Zn p/v) at a dose of 2 mL kg-1 seed, Manganese (50% Mn w/v) at a dose of 2ml kg-1 seed, Boron (3% B w/v) at a dose of 3 mL kg-1. Plants were collected at, three, seven and eleven days after emergence with readings of leaf area and estimates for dry weight of shoots and roots. From these data calculations were derived for the total plant dry mass, shoot/root ratio, ratio of leaf area to leaf mass and the specific leaf area. The compound mixture of Cu + Mo + Zn + Mn provided the highest seedling dry matter accumulation and highest leaf area, while single zinc applications stimulated the accumulation of root dry mass. Seed treatment with micronutrients provides better performance for the initial growth in rainfed rice plants.

Objetivou-se com este trabalho avaliar a influência da concentração do extrato de folhas maduras de Zantesdeschia aethiopica sobre atributos fisiológicos de sementes e plântulas de arroz vermelho. Os tratamentos foram extratos nas concentrações 0; 12; 25; 50 e 75%. Foram avaliados germinação, primeira contagem, comprimento de parte aérea e raiz, massa seca total de plântulas, condutividade elétrica, teores de clorofila a, b e total, atividade das enzimas superóxido-dismutase, catalase e ascorbarto peroxidase, peroxidação lipídica e teor de peróxido de hidrogênio, emergência de plântulas, comprimento de parte aérea e de raiz e massa seca total das plântulas emergidas. Os teores de clorofila foram alterados quanti-qualitativamente, a emergência de plântulas, o comprimento de raiz e a massa seca total de plântulas emergidas foram reduzidos pelo aumento da concentração do extrato. A peroxidação de lipídeos, a atividade das enzimas superóxido-dismutase, ascorbato-peroxidase e catalase aumentaram com a concentração. Os resultados encontrados no trabalho demonstraram que o extrato de folhas maduras de Z. aethiopica altera diferentes atributos fisiológicos e apresenta toxidez a sementes e a plântulas de arroz vermelho.

O experimento foi conduzido em casa de vegetação, na Universidade Federal de Pelotas, Campus Capão do Leão, RS, com o objetivo avaliar comparativamente o crescimento de plantas de rabanete Comprido de Ponta Branca submetido a diferentes doses de nitrogênio (0,15 e 30 kg ha-1 de N). As plantas foram coletadas a intervalos regulares de três dias a partir dos 13 dias após a semeadura até o final do ciclo da cultura. Determinaram-se a massa seca total, taxa de produção de matéria seca, taxa de crescimento relativo, taxa assimilatória líquida, índice de área foliar, taxa de crescimento relativo de área foliar, razões de área foliar e massa foliar e a área foliar específica. O tratamento de 15 kg ha-1 de N proporcionou melhores características de crescimento e maior acúmulo de matéria seca quando comparada aos demais tratamentos.

O presente trabalho objetivou avaliar comparativamente as características fisiológicas de crescimento entre duas cultivares de pimenta, em casa de vegetação. As plantas foram coletadas a partir do décimo quarto dias após o transplante (DAT), a intervalos regulares de quatorze dias após o transplante até final do ciclo de cultivo. Em cada coleta, as plantas foram separadas em órgãos (raiz, caule, folha e fruto). Foram determinadas a matéria seca total (Wt), as taxas de produção de matéria seca (Ct) e de crescimento relativo (Rw), taxa assimilatória líquida (Ea), índice de área foliar (L), taxa de crescimento relativo de área foliar (R¬a), razão de área foliar (Fa), razão de massa foliar (Fw), área foliar específica (Sa) e o índice de colheita (Hi). A partir da análise conjunta e comparativa dos dados de crescimento das cultivares de pimenta estudadas, a cultivar Vulcão obteve maiores Ea, Fa e Ra. Entretanto, menores Wt, Ct e Hi em relação a cultivar Doce. Assim, a cultivar Doce foi superior à Vulcão no que tange aos atributos de crescimento estudados, em condições de casa de vegetação.

Abstract : The objective of this work was to apply a multivariate index of vigor in soybean seeds to identify the differential effects of the genotypes x environments interaction on the quality of the seeds produced in the 2016/2017 harvest season. The experiment was conducted in a randomized block design, organized in the factorial scheme, with five seed production environments x 20 soybean genotypes, arranged in four replications. The seed production environments of Tenente Portela - RS and Santa Rosa - RS soybeans are characterized as the environments that express the highest magnitude for seed vigor index, however biometrically Sarandi - RS has been defined as the optimal environment for the production of high vigor seeds according to the tested genotypes. High seed vigor index were expressed for the genotypes TMG 7161 RR, AMS Tibagi RR, BMX Magna RR, Fepagro 37 RR and NA 5909 RG. The differential effects of the genotypes x production environments interaction of soybean seeds influenced by more than 68% the vigor index of the seeds produced.