Partitioning of assimilates and temporal distribution of productivity in grafted tomato plants

This study evaluated the morphology and partitioning of assimilates in grafted and non-grafted tomato plants in a greenhouse throughout the crop cycle. The plants were collected beginning on the 14th day after transplantation (DAT), at regular intervals of 14 DAT, until the end of the crop cycle. The dry mass of leaves, stems and fruits, number of leaves, leaf area, plant height, total number of fruits, number of unmarketable fruits, shoot/root ratio and harvest index were evaluated. Productivity was expressed in terms of mean fruit mass and non-commercial, commercial and total productivity in t ha-1 of fresh mass. Grafted plants had more leaves as well as greater allocation of dry matter to leaves and fruits, which resulted in a difference in the harvest index. However, the non-grafted plants proved superior in fruit production and in total and commercial productivity, compared to the grafted plants.(Partição de assimilados e distribuição temporal da produtividade de tomateiro submetido à enxertia). O trabalho objetivou avaliar as características morfológicas e a partição de assimilados entre plantas de tomateiro enxertado e pé-franco em ambiente protegido, ao longo do ciclo de cultivo. As plantas foram coletadas a partir do décimo quarto dia após o transplante (DAT), a intervalos regulares de 14 DAT até final do ciclo de cultivo. Foram determinados a matéria seca de folha, de caule e de fruto, o número de folhas, a área foliar, a altura das plantas, o número total de frutos, o número de frutos não comerciais, a razão parte aérea/raiz e o índice de colheita. A produtividade foi expressa pela massa média dos frutos, produtividade não comercial, comercial e total em t ha-1 de massa fresca. Plantas enxertadas apresentaram maior número de folhas, aliado à maior alocação de assimilados nas folhas e frutos, o que resultou um índice de colheita diferenciado. No entanto, o pé-franco demonstrou superioridade na produção de frutos e na produtividade comercial e total, quando comparado ao tratamento enxertado.

Desempenho de sementes, vigor e expressão isoenzimática em plântulas de teosinto (Euchlaena mexicana Schrader) sob efeito da restrição hídrica

This study aimed to evaluate seed physiological performance and isoenzyme expression in seedlings of teosinto (Euchlaena mexicana Schrader) under water restriction. For water restriction simulation, teosinto seeds were subjected to osmotic potentials of 0.0, -0.3, -0.6 and -0.9 MPa induced by polyethylene glycol 6000. We evaluated: germination; first count of the germination test; length and mass of both shoot and root dry matter; and expression of isoenzymes malate dehydrogenase, glutamate oxaloacetate transaminase, esterase and acid phosphatase. The decreased osmotic potential from -0.3 MPa impaired germination and early seedling growth. Fluid restriction in teosinto seeds negatively affects seedling performance, which may be related to alteration in expression of the isoenzymatic systems.O trabalho objetivou avaliar o desempenho fisiológico de sementes e a expressão isoenzimática em plântulas de teosinto (Euchlaena mexicana Schrader) sob restrição hídrica. Para a simulação da restrição hídrica, as sementes de teosinto foram submetidas aos potenciais osmóticos de 0,0; -0,3; -0,6 e -0,9 MPa induzida por polietilenoglicol 6000. Foram avaliados a germinação, a primeira contagem do teste de germinação, o comprimento e a massa da matéria seca de parte aérea e raiz, a expressão das isoenzimas malato-desidrogenase, glutamato-oxalacetato-transaminase, esterase e fosfatase ácida. A diminuição do potencial osmótico a partir -0,3 MPa prejudicou o processo germinativo e o crescimento inicial das plântulas. A restrição hídrica em sementes de teosinto afeta negativamente o desempenho de plântulas, fato que possivelmente mantém relação com a alteração da expressão dos diferentes sistemas isoenzimáticos

Atividade alelopática de extratos de folhas de Schinus molle L. sobre a germinação e o crescimento inicial do rabanete

This study aimed to evaluate the allelopathic activity of leaf-soft mastic (Schinus molle L.) on germination and early growth of radish (Raphanus sativus L.). Leaf extracts were prepared at concentrations of 2, 4 and 8%. pH and osmotic potential were also performed from the extracts. Germination bioassay consisted of four replicates of 25 seeds of radish distributed in Petri dishes with germitest paper and 7 mL of extract or water and kept at 25 ° C in B.O.D. for five days. Germination percentage (PG), germination rate (VG), germination speed index (IVG) and Index of allelopathic effect (RI) were determined. For bioassay initial growth, seeds were germinated (2mm protrusion of radicle) and transferred to Gerbox contained germitest paper and 15 mL of extract or water, staying seven days at 25 ° C in B.O.D. to evaluate the length of radicle and hypocotyl, mass fresh and dry, the water content and content of chlorophyll (a, b and total). Extracts of leaves S. molle affected negatively all parameters examined for germination (PG, VG, IVG and RI). For the initial growth, the extracts caused a reduction of radicle length and stimulated the growth of hypocotyl. The extracts also led to increased the fresh and dry weight but did not alter the content of chlorophyll. Thus, as the pH and osmotic potential did not affect the results, S. molle exerted allelopathic effect on radish.Este trabalho objetivou avaliar a atividade alelopática de folhas de aroeira-mole (Schinus molle L.) sobre a germinação e o crescimento inicial do rabanete (Raphanus sativus L.). Foram utilizados extratos de folhas nas concentrações 2, 4 e 8%, cujo pH e potencial osmótico foram aferidos. No bioensaio de germinação, foram empregadas quatro repetições de 25 sementes, distribuídas em placas de petri forradas com papel Germitest, umedecido com 7 mL de extrato ou água e mantidos a 25ºC em B.O.D, por cinco dias. A porcentagem de germinação (PG), velocidade de germinação (VG), índice de velocidade de germinação (IVG) e índice de efeito alelopático (RI) foram determinados. No bioensaio de crescimento inicial, sementes foram germinadas (com 2 mm de protusão da radícula) e  transferidas para Gerbox contendo papel Germitest e 15 mL de extrato ou água, permanecendo sete dias a 25 ºC em B.O.D. para a avaliação do comprimento da radícula e do hipocótilo, da massa fresca e seca, do conteúdo de água e do teor de clorofila (a, b e total). Todos os parâmetros de germinação (PG, VG, IVG e RI) foram afetados negativamente pelos extratos de S. molle. Para o crescimento inicial, os extratos causaram redução do comprimento da radícula e estimularam o crescimento do hipocótilo, aumentando, também, a massa fresca e seca não alterando os teores de clorofila. Como o pH e o potencial osmótico não interferiram nos resultados, S. molle exerceu efeito alelopático sobre o rabanete

Growth analysis of maize under waterlogging conditions

The objective of this work was to evaluate the influence of flooding on the growth of maize plants through growth analysis through simple logistics. The work was conducted in the 2016/2017 growing season. The climate is temperate, with well distributed rainfall, hot summer andthe soil is classified as solodiceutrophic haplic planosol. The experimental design was completely randomized blocks arranged in a factorial scheme, with two soil water conditions x five plant samples, arranged in four replicates. It was carried out the flooding of the parcels. The variables measured were total dry mass; dry matter production rates; relative growth rate; net assimilation rate; leaf area ratio; leaf mass ratio; maximum values of specific leaf area; leaf area index; efficiency of solar energy on version and mass partition, carried out in five collections. There is a reduction in leaf mass ratio, dry mass production rate, and relative growth rate in plants submitted to flooding, compared to those kept at field capacity. Corn plants submitted to soil flooding presented negative changes in the assimilated partition throughout their development. Soil flooding over the period of 72 hours adversely affects the physiological parameters of maize plants, leading to a reduction of their productive efficiency.The objective of this work was to evaluate the influence of flooding on the growth of maize plants through growth analysis through simple logistics. The work was conducted in the 2016/2017 growing season. The climate is temperate, with well distributed rainfall, hot summer andthe soil is classified as solodiceutrophic haplic planosol. The experimental design was completely randomized blocks arranged in a factorial scheme, with two soil water conditions x five plant samples, arranged in four replicates. It was carried out the flooding of the parcels. The variables measured were total dry mass; dry matter production rates; relative growth rate; net assimilation rate; leaf area ratio; leaf mass ratio; maximum values of specific leaf area; leaf area index; efficiency of solar energy on version and mass partition, carried out in five collections. There is a reduction in leaf mass ratio, dry mass production rate, and relative growth rate in plants submitted to flooding, compared to those kept at field capacity. Corn plants submitted to soil flooding presented negative changes in the assimilated partition throughout their development. Soil flooding over the period of 72 h adversely affects the physiological parameters of maize plants, leading to a reduction of their productive efficiency

Development and productivity of soybean sown in the off-season

The objective of this work was to evaluate the influence of different sowing times on plant height and yield of soybean seeds produced in two consecutive years and in two seasons in the off-season period. The experiment was carried out in an open field, at the Federal University of Pelotas, in the municipality of Capão do Leão, RS. The experimental design was completely randomized. In order to evaluate growth attributes and yield characters, the plant height, number of pods, seeds per plant, seed production, number of seeds per pod. Sowing at different times of the off-season affects in a different way the production of soybean seeds. Sowing at the end of February negatively affects plant height and soybean seed production in relation to sowing in early January.The objective of this work was to evaluate the influence of different sowing times on plant height and yield of soybean seeds produced in two consecutive years and in two seasons in the off-season period. The experiment was carried out in an open field, at the Federal University of Pelotas, in the municipality of Capão do Leão, RS. The experimental design was completely randomized. In order to evaluate growth attributes and yield characters, the plant height, number of pods, seeds per plant, seed production, number of seeds per pod. Sowing at different times of the off-season affects in a different way the production of soybean seeds. Sowing at the end of February negatively affects plant height and soybean seed production in relation to sowing in early January

Ação de níveis de luminosidade sobre o crescimento de plantas de maria-pretinha (Solanum americanum Mill.)

This work aimed to evaluate the effect of light levels on performance and plasticity of Solanum americanum Mill plants. Twelve collections were made at regular intervals seven days after transplanting, and separated into organs. Luminosity levels of 35%, 65% and full light (100%) were used, and height, number of leaves, leaf area, relative growth rate of leaf area, shoot and root ratio, fruit dry matter ratio and total dry matter were evaluated. The highest number of leaves occurred in plants under 65% of luminosity, and the superior leaf area on those under luminosity of 35 and 65%. The relative growth rate of leaf area was higher on seventh day after transplanting in plants under luminosity of 35% and under full light. Plants under luminosity of 65% had a higher ratio of shoot and root and similar height. Dry matter ratio of fruit and total was quantitatively modified by reducing luminosity. The different levels of luminosity distinctly influenced growth and plasticity of S. americanum Mill plants.Este trabalho objetivou avaliar o efeito de níveis de luminosidade sobre o desempenho e a plasticidade de plantas de Solanum americanum Mill. As doze coletas foram efetuadas a intervalos regulares de sete dias após o transplante e separadas em órgãos. Foram utilizados níveis de luminosidade de 35; 65% e luz plena (100%) e avaliados a altura, o número de folhas, a área foliar, taxa de crescimento relativo de área foliar, razão parte aérea e raiz e a razão massa seca de fruto e massa seca total. O maior número de folhas ocorreu em plantas sob luminosidade de 65% e a superior área foliar naquelas sob luminosidade de 35% e 65%. A taxa de crescimento relativo de área foliar foi maior aos 7 dias após o transplante em plantas sob luminosidade de 35% e luz plena. Plantas sob luminosidade de 65% apresentaram maior razão parte aérea e raiz e similar altura. A razão massa seca de fruto e massa seca total foi modificada quantitativamente pela redução da luminosidade. Os diferentes níveis de luminosidade influenciaram distintamente o crescimento e a plasticidade de plantas de S. americanum

Effect Of Soil Waterlogging Stress On The Physiological Performance Of Seeds And On The Productivity Of Rye Plants

Summary The objectives of this study were to evaluate the effect of waterlogging on seed physiological performance and plant productivity in rye. Our study consisted of three treatments: 1) no waterlogging, 2) a single waterlogging period, and 3) double waterlogging period. Plant productivity was evaluated from the number of spikes per plant, the number of seeds per plant, the number of seeds per spike, and seed yield. Seeds were exposed to a germination test and seed physiological quality was evaluated from the seed germination rate, initial germination rate, germination speed index, electric conductivity, shoot length, primary root length, shoot dry matter and primary root dry matter, and weight per 1000 seeds. The seeds derived from plants not exposed to waterlogging showed a higher germination rate in a shorter period of time and higher germination speed index than those derived from plants that were exposed to waterlogging; however, the weight per 1000 seeds was lower and seedlings had longer shoots and primary roots. The plants that were not exposed to waterlogging had a higher number of spikes per plant, higher number of seeds per plant, higher number of seeds per spike, and better seed yield per plant. Therefore, it was concluded that waterlogging has a negative effect on seed physiological performance in rye and that plant productivity is reduced under long-term waterlogging. Keywords: Secale cereale L., abiotic stress, seed physiological quality, plant productivity Efecto estresante del anegamiento del suelo sobre el rendimiento fisiológico de semillas y sobre la productividad de plantas de centeno Resumen El objetivo de este trabajo fue evaluar el efecto del anegamiento del suelo sobre el comportamiento fisiológico de las semillas y la productividad de las plantas de centeno. Nuestro estudio consistió en tres tratamientos: 1) sin anegamiento; 2) un período de anegamiento; 3) dos períodos de anegamiento. La productividad de la planta se evaluó a partir del número de espigas por planta, el número de semillas por planta, el número de semillas por espiga y el rendimiento de las semillas. Las semillas fueron sometidas a una prueba de germinación para evaluar la calidad fisiológica de acuerdo a la tasa de germinación, tasa de germinación inicial, índice de velocidad de germinación, conductividad eléctrica, longitud del tallo, longitud de la raíz primaria, materia seca de la raíz y del tallo y peso de mil semillas. Las semillas de plantas no expuestas al anegamiento del suelo alcanzaron mayor porcentaje de germinación en menos tiempo y registraron mayores valores del índice de velocidad de germinación. Sin embargo, presentaron un menor peso de mil semillas, y las plántulas registraron mayor longitud del tallo y de la raíz primaria. Las plantas no expuestas al anegamiento tuvieron mayor número de espigas por planta, mayor número de semillas por planta, mayor número de semillas por espiga, y mejor rendimiento de semilla por planta. Por lo tanto, se Agrociencia Uruguay 42 concluye que el anegamiento del suelo en largos períodos afecta negativamente el rendimiento fisiológico de la semilla y la productividad de la planta de centeno. Palabras clave: Secale cereale L., estrés abiótico, calidad fisiológica de la semilla, productividad de la plant

PARÂMETROS FISIOLÓGICOS DE MUDAS DE Albizia niopoides PRODUZIDAS EM DIFERENTES COMPOSIÇÕES DE SUBSTRATO

The work aimed to evaluate the influence of composition a substrate organo-sandy on emergence and physiological parameters of angico-white seedlings. The seeds were subjected to germination in the following compositions of substrate: T1) 100% sand; T2) 75% sand + 25% Tecnomax®; T3) 50% sand + 50% Tecnomax®, T4) 25% sand + 75% Tecnomax®; 100% Tecnomax®T5).The evaluations were performed at 45, 90, 135 and 180 days after sowing (DAS) and measured the dry mass of the shoot and stem diameter. The180 DAS determined the dry mass of shoot, root and dry mass total, content of chlorophyll a, b and total. The composition T1 (100% sand) provided more height  when angico seedlings in the four evaluation times. Dry mass of the shoot and root was higher in the composition T2 at 180 DAS, the same was obtained for the Dickson Quality Index (IQD). The content of chlorophyll presented modification qualitative and quantitative to according to the substrate composition. Seed vigor expression is affected by substrate composition, and its is higher on substrates whose composition contains sand. The combination of Tecnomax® and sand, is organo-substrate, with employment potential for the production of angico-white seedlings.O trabalho objetivou avaliar a influência da composição de um substrato organoarenoso sobre emergência e parâmetros fisiológicos de mudas de angico-branco. As sementes foram submetidas à germinação nas seguintes composições do substrato: T1) 100% areia; T2) 75% areia + 25% Tecnomax®; T3) 50% areia + 50% Tecnomax®, T4) 25% areia + 75% Tecnomax®; T5) 100% Tecnomax®. As avaliações foram efetuadas aos 45, 90, 135 e 180 dias após a semeadura (DAS), sendo aferidos a altura de parte área e o diâmetro do coleto. Aos 180 DAS determinou-se a massa seca de parte aérea e de raiz, a massa seca total e os teores de clorofila a, b e total. A composição T1 (100% areia) proporcionou maior altura em mudas de angico nas quatro épocas de avaliação. A massa seca da parte área e de raiz foi superior na composição T2 aos 180 DAS, assim como a massa seca de raiz, o mesmo foi obtido para o índice de qualidade de Dickson (IQD). Os teores de clorofila apresentaram modificação quali-quantitativa de acordo com a composição do substrato. A expressão do vigor da semente de angico-branco é afetada pela composição do substrato, sendo superior em substratos cuja composição contenha areia. A combinação entre Tecnomax® e areia constitui substrato organoarenoso, com potencial de emprego para produção de mudas de angico-branco

Atividade alelopática de extratos aquosos de folhas de rabo-de-bugio sobre a germinação e o crescimento inicial de plântulas de alface

This work aimed to evaluate the allelopathic action of aqueous leaf extracts monkey tail on the germination and early growth of lettuce. The concentrations were 0; 2; 4 and 8%. We evaluated the germination, the speed index and germination rate, the length of the hypocoyl and radicle, the total dry mass and water content. The speed index and germination rate was reduced by increasing the extract concentration of fresh and dry leaves. The radicle length was reduced by increasing the concentration of the extract, with more drastic effect on lettuce seedlings of the action of dry leaves extracts. The hypocotyl length of seedlings, under the action of fresh leaves extract, increased with concentration. The seedling dry mass, for both fresh and dry leaves extract, was reduced on concentration 8% of the extract. The water content was affected by the extract of fresh leaves from the 4% concentration. The aqueous extract of fresh and dry leaves of monkey tail, affect differently the germination and early growth of lettuce seedlings, being more drastic inhibitory results exercised by extract of dry leaves and higher concentrations.Este trabalho objetivou avaliar a ação alelopática de extratos aquosos de folhas de rabo-de-bugio sobre a germinação e o crescimento inicial de alface. As concentrações empregadas foram 0; 2; 4 e 8%. Foram avaliados a germinação, o índice de velocidade e a velocidade de germinação, o comprimento de hipocótilo e de radícula, a massa seca total e o conteúdo de água. A velocidade e o índice de velocidade de germinação foram reduzidos ao aumentar a concentração do extrato de folhas frescas e secas. O comprimento de radícula foi reduzido ao aumentar a concentração do extrato com efeito mais drástico em plântulas de alface sobre ação de extratos de folhas secas. O comprimento do hipocótilo de plântulas sob ação do extrato de folhas frescas aumentou com a concentração. A massa seca de plântulas, tanto para o extrato de folhas frescas quanto secas, foi reduzida somente na concentração 8% do extrato. O conteúdo de água foi afetado pelo extrato de folhas frescas a partir da concentração 4%. O extrato aquoso de folhas frescas e secas de rabo-de-bugio afetam de forma distinta a germinação e o crescimento inicial de plântulas de alface, sendo resultados inibitórios mais drásticos exercidos pelo extrato de folhas secas e maiores concentrações

Nitrogênio em soja: qualidade fisiológica das sementes

The objective of this study was to evaluate the yield and physiological quality components of soybean seeds grown with application of different doses and times of application of nitrogen. The completely randomized design, in a 4x2 factorial scheme (four nitrogen doses and two application times) with four repetitions. The application of nitrogen was done in the form of urea (45% N), in the doses of 0, 25, 50 e 75 kg N ha- 1 during sowing and at the R4 stage of the culture. The number of pods per plant, the number of seeds per plant, the mass of a thousand seeds, first germination count, percentage of germination, dry mass of aerial part and root were evaluated. The application of nitrogen positively influenced the parameters of soybean yield at the dose of 75 kg N ha-1 during grain filling. During sowing, the dose of 25 kg N ha-1 resulted in higher averages of the dry mass of aerial part, 50 kg N ha-1 increased the mass of one thousand grains and dry root mass and the application of 75 kg N ha-1 at sowing during the first harvest obtained positive results for the first germination and germination count. For the results of the second crop, the application of 50 kg N ha-1 at sowing provided an increase in the first germination count.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