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Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In fragile environments, no-tillage (0T) instead of conventional tillage (CT) is desirable to prevent agroecosystem degradation, but there is little information on its implementation in horticulture. This study aimed to investigate the effects of replacing CT with 0T on floristic composition and weed emergence dynamics in a garlic crop, under the hypothesis that the implementation of a 0T system alters the weed community during the initial stage of the transition. Two experiments were carried out following a randomized complete block design with two treatments (garlic crop grown under 0T and CT). In two subsampling per plot, biweekly destructive weed surveys were carried out. Although both tillage systems presented a similar diversity between systems, these weed communities varied by 36% in their species identity, and it was recorded a higher total weed density under CT (P>0.05). Under 0T, anemophilous Asteraceae, such as Conyza bonariensis and Sonchus oleraceus, tended to increase their presence. Under CT, there was a greater amount of indehiscent fruiting Brassicaceae such as Raphanus sativus and Rapistrum rugosum. The implementation of Vicia villosa as a predecessor crop led to many births due to its capacity for natural reseeding. It is concluded that there are important changes in the species composition and weed emergence patterns immediately after the implementation of 0T compared to CT, suggesting that the filtering pressures exerted by each tillage system favor certain weed species over others. By understanding weed community shifts and critical stages of weed emergence, farmers can improve herbicide application, thereby reducing the excessive use of chemicals and minimizing environmental impact. In addition, this information can help to schedule labor and machinery more efficiently, saving time and production costs. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Weedy biotypes of Oryza sativa L., (weedy rice) are a serious threat to rice production because of their flexibility in seed germination timing, variable growth forms, and high genetic diversity. Experiments were designed to determine the effects of storage conditions, osmotic stress, pH, salt stress, and burial depth on germination of weedy rice seeds in flooded or non-flooded conditions. Mature weedy rice seeds were gathered from rice fields in the different regions of Turkey. Three biotypes were selected and classified according to awn length; long awn, short awn and awnless. Seasonal germination patterns of weedy rice seeds in the laboratory after retrieval from various depths and timing were affected by burial depth, water regime, and exhumation timing across the treatments for all biotypes. The long and short awn biotypes had higher germination rates than the awnless biotype and did not have a seasonal germination pattern. Seed germination was initiated in the spring, peaked in summer and declined in the fall in flooded and non-flooded treatments for the awnless biotype. The most distinct differences in seedling emergence patterns were observed in awnless and long awn biotypes, and they emerged from 10 cm depth. Our results suggested that flooded conditions reduced the germination of weedy rice biotypes. Flooding rice paddies for a period of time after harvest may improve weedy rice control and decrease the weed population. In addition to deeper cultivation would be more effective in controlling all weedy biotypes since the majority of weed seedling emergence was from shallow depths. [ABSTRACT FROM AUTHOR]

Copyright of Investigación Agraria is the property of Investigacion Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The seed provenance can interfere with their size, as well as in the growth of saplings and susceptibility to stress. The aim of this study was to evaluate the quality of Brosimum gaudichaudii Trécul seeds and seedlings obtained from two different locations. Seeds were collected in two municipalities in the state of Goiás - Iporá and Jataí, in 2018. Individual seed size mass and dimension, seedling emergence percentage and speed, as well as initial growth, leaf chlorophyll index, biomass and seedling quality index (SQI) were determined. Such parameters were determined at 40, 70, 100, 130, 160 and 190 days after sowing (DAS). Individual size mass and dimension of seed collected in Iporá were superior to those collected in Jataí. Despite this, the seedling emergence percentage and seedling mortality were not affected by the different origins of seeds. As expected, there was increase in height, stem diameter and number of leaves of seedlings during the analyzed period, on the other hand, the chlorophyll index remained constant. The initial growth of seedlings differed between origins. The dry biomass did not vary between seedlings from the different origins, with greater allocation of biomass in roots. The SQI of seedlings produced from seeds collected in Iporá was higher than those collected in Jataí. Despite the quality verified for seeds and seedlings from the two origins, seeds collected in Iporá presented larger dimensions than those collected in Jataí, generating seedlings with greater initial growth and higher quality. [ABSTRACT FROM AUTHOR]

Contextualization: The mung bean is widely cultivated in Asia and Brazil, it has emerged as an option for cultivation in the second crop in the Central West Brazil, especially rotation with grasses is intended; however, the uneven and slow emergence of mung bean seedlings can lead to delays in the development of the crop and impair the final stand. Knowledge gap: Some of the conditions that affect the initial establishment of the crop are the sowing depth and the size of the seed. These factors are still under discussion in the scientific environment, especially for a culture recently introduced in Brazil. Purpose: the objective was to evaluate the effect of seed size and sowing depth standardization on the performance of mung bean seedlings. Methodology: The trial was conducted in a Red Latosol, with Aw climate, average annual rainfall of 1300 mm and bimodal distribution. The experimental design used was completely randomized, in a 2 × 3 factorial scheme with 8 replicates of 25 seeds, totaling 48 plots. The factors analyzed were two seed size (3 and 4 mm) and three sowing depths (1, 2 and 3 cm). The emergency speed index (ISE), non-emerged seedlings, normal seedlings, fresh mass, dry mass and seedling length were evaluated. The data were submitted to variance analysis and, when significant at 5% probability, a Tukey test was applied to compare the means of the factors under study. Results and conclusions: It was verified that, when sown at 1 cm depth, the seeds of mung bean have lower ISE, however, they obtained a lower percentage of seedlings not relevant for the study, and a higher percentage of normal seedlings emerged than at a depth of 3 cm. Thus, the most recommended depth for the sowing of mung beans was 2 cm, regardless of the size of the seed used. The seed class of 4 mm allowed the development of seedlings with higher dry matter accumulation. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Agricolas is the property of University of Narino, Faculty of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El roble colombiano (Quercus humboldtii) es una especie endémica, dominante y vulnerable de los bosques altoandinos. Su madera y fruto se han utilizado tradicionalmente en pequeña escala por las poblaciones rurales. Una mayor sincronía del proceso de germinación podría facilitar la producción de plántulas para su uso en los programas de conservación. En vivero, se evaluó la emergencia mediante la inmersión de semillas en cuatro soluciones de ácido giberélico (GA3) por 24 horas (0, 150, 300 y 600 mg L-1), a 4 °C. Se adoptó un diseño completamente al azar con cuatro repeticiones de 25 semillas. El tiempo medio de emergencia tuvo una media de 32 días; sin diferencias estadísticamente significativas entre las diferentes dosis. No hubo efecto del GA3 para la emergencia de plántulas hasta 300 mg L-1 (media= 92 %); sin embargo, fue desfavorable con 600 mg L-1 (20 %). Las semillas frescas de roble andino poseen un alto contenido de humedad (38 %). Lo anterior revela un probable comportamiento recalcitrante. Este estudio confirma, como en la mayoría de los encinos blancos del trópico, la ausencia de latencia y la alta viabilidad de sus semillas. El uso del GA3 no es un tratamiento pregerminativo útil para acelerar y uniformizar la emergencia de plántulas de Q. humboldtii.

The aim of this study was to establish a methodology to determine physiological vigor in small and large seeds of Hymenaea courbaril L. non-scarified seeds and scarified by the electrical conductivity test and period of seed soaking in water aiming at maximum capacity of emergence and seedling vigor. The design was completely randomized, in a 2 x 2 x 5 factorial scheme (two classes of seed mass, non-scarified seeds and scarified and five periods of soaking in water), with 10 replicates of 10 seeds each. The variables evaluated were electrical conductivity (µS cm-1.g-1), emergence speed (index), seedling emergence (%) and mean time of emergence (days), obtained by means of daily counts until stabilization in the values. Maximum vigor of Hymenaea courbaril seedlings is obtained with large seeds subjected to scarification and soaked in water for six hours. Water content of 18.7% in large seeds of Hymenaea courbaril scarified promotes the production of 100% of vigorous seedlings. Small and large seeds of Hymenaea courbaril non-scarified seeds and scarified, soaked for six hours, had shorter mean time for seedling emergence. Water content of 20.6% in small seeds of Hymenaea courbaril scarified promotes 100% seedling emergence. The electrical conductivity test applied to Hymenaea courbaril seeds can be adopted to determine seed vigor, showing speed in the obtaining of results and ease of execution. [ABSTRACT FROM AUTHOR]

At eutrophic shallow subtropical lakes, free-floating macrophytes can occupy the entire water surface. The removal of this vegetation favors the recolonization of submerged macrophytes from the propagule bank. Our study presents the response of the propagule bank of a shallow subtropical lake after management to reduce its hypertrophy. We sampled lake sediment in March 2016 at 15 points along three transects to investigate the richness and density of the propagule bank by emergence in the laboratory. We monitored water trophic conditions and restoration of vegetation in the field for 7 months. In the laboratory, 1382 seedlings of eight species emerged. Stuckenia pectinata and Chara zeylanica dominated the propagule bank. We identified the species S. pectinata, C. zeylanica and Ludwigia peploides in the field. The propagule bank was homogeneous, without difference (P>0.05) between lake regions and transects. Sørensen's similarity was 36% between the field and laboratory. When the submerged macrophytes grew in the field, there was a reduction of chlorophylla, the water remained clear, and the trophic state index was reduced from hypereutrophic to eutrophic. We concluded that the bank of propagules in shallow lakes is essential for the rapid reestablishment of submerged macrophytes after recovery strategies. These organisms help improve water quality. [ABSTRACT FROM AUTHOR]

For the replanting of the sugarcane crop, plants produced from buds of different reserve sizes and from different positions on the stem are used, without up to now an optimum reserve and position size has been determined to obtain a quality plant. Therefore, five treatments were evaluated for nutritional reserve: T1 (short reserve), T2 (without reserve), T3 (half reserve), T4 (long basal reserve) and T5 (long reserve superior) and for the position a design was used 2x3 factorial (two cultivars: MEX69-290 and COLPOSCTMEX05-223 and three yolk positions: basal, middle and apical), the treatments were distributed in a completely randomized arrangement. The buds were sown in unicel vessels with a liter capacity and sifted sand was used as substrate. It was evaluated; emergency percentage, root length and plant height. The results indicate that the use of buds with different positions in the stem is possible to produce seedlings of good quality, since more than 50% of sprouting was obtained in both cultivars. The results on nutrient reserves showed that T3 had the longest root length (36.2 cm) and T1 had the highest plant height (61.4 cm), showing that there is no direct relationship between plant height and root length. To obtain a quality plant it is enough to use short buds or half reserve and any position. For the commercial production of plants, it is recommended to plant in substrates rich in nutrients.

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Annual ryegrass seeds having low physiological quality can lead to the formation of pastures with undesirable plant stands for soil cover and forage utilization pastures. Thus, the objective of this study was proposing a vigor test to classify annual ryegrass seeds. For that, different sowing depths (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm) over three substrates (sand, coconut fiber, and carbonized rice husk) were tested to differentiate the physiological quality of four seed lots of annual ryegrass cv. BRS Ponteio having similarities in germination and moisture. The seed lots were classified according to vigor through the field seedling emergence (FSE), 1,000-seeds weight, saturated salt accelerated aging, and germination first count. The 2.5 cm of sand sowing depth and 3.0 cm of coconut fiber sowing depth provided separation of seed lots in similar groups of those reported to FSE test through the seedling emergence and speed of seedling emergence tests. [ABSTRACT FROM AUTHOR]

In soybean crops, industrial seed treatment is widely adopted, and it has allowed the development of new technologies, such as the use of dry powders. This work aimed to evaluate the effect of the industrial treatment, with and without the additional application of dry powder, on the physiological potential of soybean seeds. The experimental design was completely randomized, in a 4x2 factorial scheme, with four replications. Four chemical treatments were evaluated: 1) control, 2) carbendazim + thiram + thiamethoxam, 3) carbendazim + thiram, 4) thiamethoxam. Each trial was divided into one group that was treated and the other that remained untreated with the dry powder. The cultivars BRS 360 RR and BRS 284 were used and analyzed separately. The physiological potential of the seeds was determined by the following assessments: germination, first germination count, seedling emergence in sand, seedling total length, shoot length, and root length. Soybean cultivars respond differently to seed chemical treatments, regarding the effects on physiological potential. Using the dry powder results in problems in seed germination speed in the cultivar BRS 284. In the cultivar BRS 360 RR, the use of dry powder associated with thiamethoxam treatment reduces the physiological potential of the seeds. [ABSTRACT FROM AUTHOR]

A dificuldade técnica devida à ocorrência de dormência das sementes é um entrave para a produção de mudas de espécies nativas em programas de recomposição de áreas degradadas do Cerrado. Objetivou-se com este trabalho avaliar o efeito do condicionamento fisiológico e do sombreamento na qualidade de sementes de duas espécies de barbatimão (Stryphnodendron polyphyllum e S. adstringens). Foram utilizados os seguintes tratamentos pré-germinativos: 1) PEG -1,0 MPa; 2) PEG -1,0 MPa+ KNO3 -1,0 MPa; 3) PEG -0,5 MPa; 4) PEG -0,5 MPa + KNO3 -0,5 MPa; 5) KNO3 -1,0 MPa; 6) Água deionizada; e 7) sementes que não receberam nenhum tratamento pré-germinativo (testemunha). Durante os tratamentos pré-germinativos, as sementes permaneceram incubadas em B.O.D. regulada na alternância de 20/30 ºC, durante 24 h, e em seguida semeadas em bandejas de células com Plantmax® mantidas em quatro níveis de sombreamento (pleno sol, 30%, 50% e 70%) com quatro repetições de 20 sementes. O condicionamento fisiológico com água de sementes de S. polyphyllum e S. adstringens e posterior semeadura em ambiente sombreado de 50 a 70% são eficientes para obter emergência rápida e elevada, maior altura e massa seca das plântulas. As sementes de S. polyphyllum podem ser osmocondicionadas com PEG 1,0 e PEG -0,5 MPA se a semeadura for realizada sob 30% de sombra. Entretanto, a semeadura de S. polyphyllum e S. adstringens não deve ser realizada a pleno sol.

The aim of this work was to evaluate the effect of different spray volumes, via industrial treatment, on the physiological quality of soybean seeds with different levels of vigor. The experimental design was completely randomized in a 2x5 factor scheme, with four replications. Factors consisted in two levels of seed vigor (high and low) and five spray volumes (0, 600, 1200, 1800 and 2400 mL. 100 kg-1). Products used to obtain the volumes were: fungicide (carbendazin + thiram); insecticide (imidacloprid + thiodicarb); nematicide (abamectin); micronutrients (cobalt, molybdenum and zinc); polymer (peridiam); biostimulants (kinetin + gibberellic acid) and inoculum (Bradyrhizobium japonicum). The used cultivars were BRS 360 RR and BRS 1010 IPRO. The physiological seed quality was determined by the following evaluations: germination, first count of the germination test, seedling emergence in sand, emergency speed index, total length of shoot and root of the seedlings. In the different spray volumes, high vigor soybean seeds have higher physiological quality than low vigor seeds. The increased spray volumes in seed treatments reduce the physiological quality of low vigor soybean seeds. [ABSTRACT FROM AUTHOR]

The aim of this research was to compare genetic parameters for traits related with seed germination and seedling vigour of single cross (SCH) vs. three-way (TWH) sorghum hybrids. The study was conducted in a sand bed under a greenhouse; 67 genotypes (four pairs of A- and B- lines, four R- lines, 13 SCH and 42 TWH) were allocated in a randomized complete blocks experimental design with three replications. Statistical analysis included ANOVA's and Student "t" tests, while Tukey test (p = 0.05) was applied for mean comparisons. The R-lines showed better physiological seed quality attributes than the Aand B- lines. The seed quality and heterosis values of SCH vs. that of TWH did not show significant differences (p > 0.05) for any variable; however, heterobeltiosis of SCH was higher than that of TWY for normal seedlings, dry weight of plumule and seedling emergence rate. The A2-line and R14 restorer line showed the highest GCA values in both types of hybrids. No differences (p ≤ 0.05) were found between maternal and paternal effects of the A- and B- lines involved in the male sterile cross (female parent) of the TWH, except for plumule length in Line 5. [ABSTRACT FROM AUTHOR]

A produção de mudas é uma das etapas fundamentais para o cultivo do tomateiro e pode ser influenciada pela temperatura inicial de germinação. Nesse sentido, o objetivo deste trabalho foi avaliar o efeito desse fator no desempenho de plântulas e mudas de tomate. Foram utilizados quatro lotes de sementes de tomate híbrido Mariana, submetidos aos testes de germinação, envelhecimento acelerado e condutividade elétrica para a avaliação do potencial fisiológico. Após a caracterização dos lotes, as sementes foram submetidas a diferentes temperaturas iniciais de germinação (20-30 alternada, 30, 33 e 35°C constantes) para determinação da curva de embebição e para análise de plântulas por meio do software SVIS®. Sementes submetidas às mesmas temperaturas foram destinadas à produção de mudas e o desempenho destas foi avaliado por meio da velocidade e porcentagem de emergência, altura e massa seca da parte aérea e das raízes. As temperaturas mais elevadas prejudicam o desenvolvimento inicial das plântulas, porém as mudas submetidas às diferentes temperaturas, aos 28 dias após a semeadura, estavam com desempenho semelhante.

Rhynchosia capitata is becoming an increasing problem in summer crops, such as cotton, soybean, pearl millet and mungbean in many Asian countries. Laboratory and greenhouse studies have been conducted to determine the effects of several environmental factors on seed germination patterns and seedling emergence of R. capitata. We investigated whether the diverse ecological factors such as temperature, light, salinity, moisture stress, pH, and soil depth affected germination and seedling emergence of R. capitata. Germination increased as temperature increased from 25ºC and significantly reduced at 45ºC. Presence or absence of light did not influence germination. Germination of R. capitata was sensitive to increased salt and moisture stress, as well as to seed burial depth. Only 48% of seeds germinated at 150 mM salt concentration compared to 100% in control (distilled water). Similarly, 15% of seeds germinated at an osmotic potential of ‑0.8 MPa compared to 88% at ‑0.2 MPa. The optimum pH for seed germination of R. capitata was 7 (98% germination), but the seeds also germinated at lower level of pH 5 (85%) and at higher level of pH 10 (75%). In seed burial trial, maximum seedling emergence of 93% occurred at 2 cm depth, and seedling did not emerge from a depth of 12 cm. The high germination ability of R. capitata under a wide range of ecological factors suggests that this species is likely to be the one to cause more problems in a near future, if not managed appropriately.A Rhynchosia capitata vem se tornando um problema crescente para culturas de verão como algodão, soja, milheto e feijão-mungo em muitos países asiáticos. Foram feitos estudos de laboratório e estufa para determinar os efeitos de vários fatores ambientais sobre os padrões de germinação das sementes e emergência das plântulas de R. capitata. Diversos fatores ecológicos, tais como, temperatura, luz, salinidade, estresse hídrico, pH e profundidade do solo foram avaliados para saber se afetam a germinação e emergência das plântulas de R. capitata. A germinação aumentou à medida que a temperatura aumentou a partir de 25ºC e reduziu significativamente a 45ºC. A presença ou ausência de luz não influenciou a germinação. A germinação das sementes de R. capitata se mostrou sensível ao aumento dos estresses hídrico e salino, bem como à profundidade do enterrio das sementes. Apenas 48% das sementes germinaram a 150 mM de concentração salina, em comparação com 100% no controle (água destilada). Do mesmo modo, 15% das sementes germinaram a um potencial osmótico de -0,8 MPa, em comparação com 88% a -0,2 MPa. O pH ideal para a germinação de sementes de R. capitata foi 7 (98% de germinação), mas as sementes germinaram também a um nível inferior de pH 5 (85%) e superior de pH 10 (75%). No experimento de enterrio das sementes, a máxima emergência das plântulas de 93% foi a 2 cm de profundidade e as plântulas não emergiram a partir da profundidade de 12 cm. A alta capacidade de germinação da R. capitata sob uma ampla gama de fatores ecológicos sugere que provavelmente esta espécie será a que mais causará problemas em um futuro próximo se não for gerida de forma adequada.

The majority of Arecaceae species presents difficulties to germinate, even under appropriate conditions, complicating the seedlings production process. This study aimed at evaluating the influence of seed scarification and soaking in the emergence and development of Mauritia flexuosa seedlings. The treatments consisted of a combination of seed soaking and scarification methods, in a completely randomized design, in a 2 x 3 + 1 factorial scheme, with five replications. Seeds with and without scarification, combined with soaking methods (not soaked seeds and seeds soaked for 30 days, with and without daily water renewal), plus an additional treatment, where the seeds were scarified after soaking for 30 days, were tested. The seedlingemergence up to 146 days after sowing (d.a.s.) was evaluated, as well as the emergence rate index (46 and 146 d.a.s.) and growth components (146 d.a.s.). The results were submitted to the variance analysis (F test) and means compared by using the Tukey test, at 5%. It was possible to conclude that the Mauritia flexuosa seeds presented tegument dormancy. The seed scarification increased the germination rate, however, it contributed to increase the seeds mortality rate. The soaking of nonscarified seeds for 30 days, with daily water renewal, improved the potential for seed germination. The mechanical scarification, without or after soaking the seeds in water, increased the Mauritia flexuosa seedlings mortality rate, and it is not, therefore, a suitable method for dormancy breaking. = A maioria das espécies de Arecaceae apresenta dificuldades para germinar, mesmo sob condições adequadas, dificultando a produção de mudas. Objetivou-se, com este trabalho, avaliar a influência da escarificação e embebição de sementes na emergência e desenvolvimento de mudas de buritizeiro. Os tratamentos foram compostos pela combinação de métodos de embebição e escarificação de sementes, adotando-se o delineamento inteiramente casualizado, no esquema fatorial 2 x 3 + 1, com cinco repetições. Foram testadas sementes com e sem escarificação, combinadas com métodos de embebição (sementes não embebidas e sementes embebidas por 30 dias, com e sem renovação diária de água), além de um tratamento adicional, onde as sementes foram escarificadas após a embebição por 30 dias. Foi avaliada a emergência de plântulas aos 46, 66, 86, 106, 126 e 146 dias após a semeadura (DAS), bem como o índice de velocidade de emergência (46 e 146 DAS) e os componentes de crescimento (146 DAS). Os resultados foram submetidos à análise de variância (Teste F) e as médias comparadas pelo teste Tukey, a 5%. Concluiu-se que as sementes de buriti apresentam dormência tegumentar. A escarificaçãode sementes aumenta a velocidade de emergência, entretanto, contribui para o aumento na taxa de mortalidade das sementes. A embebição de sementes não escarificadas por 30 dias, com renovação diária de água, melhora o potencial germinativo das sementes. A escarificação mecânica, sem ou após a embebição das sementes em água, aumenta a mortalidade de plântulas de buritizeiro, não sendo, portanto, um método adequado para a superação de dormência.

Knowing the importance of preventive use of insecticides for seed treatment, this study aimed to identify potential insect pests of storage for seeds of radish by means of traps set on the field for six months and to evaluate the effect of natural and synthetic substances insecticides on the emergence of radish seedlings stored for 120 days. The bioassay, field-level, was conducted over a period of six months in the following environments: savannah, area of cultivation of crops, pasture and forest at the Federal Institute Goiano. For each of these environments were placed five traps made of PET bottles, containing respectively in maize, millet, soybean, crambe and wild radish. The traps were inspected every seven days to verify the the occurrence of insects plague. The substances were: 1) saffron, 2) limestone, 3) Gray, 4) neem, 5) diatomaceous earth, 6) chlorpyrifos, 7) deltamethrin and 8) control treatment. The experimental design was randomized blocks in factorial scheme 8 x 2 (8 substances and two storage periods, is not stored seeds and seeds stored for 120 days) with four replications. Were evaluated the percentage of emergence, hold rate of emergence, time to reach 50% emergence and the record of the dry mass of seedlings. The natural and synthetic substances do not interfere with seedling emergence in seeds of wild radish, even after storage for 120 days in a room. In the traps in the field, containing seeds of wild radish noted the presence of the insect Carpophilus sp. Sabendo da importância do uso preventivo de inseticidas no tratamento de sementes, esta pesquisa teve por objetivos identificar possíveis insetos praga de armazenamento para sementes de nabo forrageiro por meio de armadilhas montadas em campo durante seis meses e avaliar o efeito de substâncias inseticidas, naturais e sintéticas na emergência de plântulas em sementes de nabo forrageiro armazenadas por 120 dias. O bioensaio, em nível de campo, foi conduzido por um período de seis meses nos seguintes ambientes: cerrado, área de cultivo de grandes culturas, pastagem e mata do Instituto Federal Goiano. Para cada um desses ambientes foram colocadas cinco armadilhas confeccionadas em garrafas PET, contendo respectivamente sementes de milho, milheto, soja, crambe e nabo forrageiro. As armadilhas foram inspecionadas a cada sete dias para a verificação da ocorrência de insetos praga. As substâncias consistiram de: 1) açafrão, 2) calcário, 3) cinza, 4) nim, 5) terra de diatomáceas, 6) clorpirifós, 7) deltametrina e 8) tratamento controle. O delineamento experimental foi em blocos ao acaso, no esquema fatorial 8 x 2, sendo oito substâncias e armazenamento por zero e 120 dias, com 4 repetições. Avaliaram-se porcentagem de emergência, índice de velocidade de emergência, tempo para atingir 50% da emergência e massa seca das plântulas emergidas. As substâncias naturais e sintéticas não interferem na emergência de plântulas em sementes de nabo forrageiro, mesmo após o armazenamento de 120 dias em sala climatizada. Nas armadilhas em campo contendo sementes de nabo forrageiro, foi observado a presença do inseto Carpophilus sp.

Three trials were carry out at Garça Municipal County, São Paulo, Brazil in order to study the effects of sowing depth of three castor bean cultivars submitted or not to dinitroaniline herbicides application in pre-emergency. The three cultivars chosen as fllow: AL Guarany 2002 variety and Iris and Savana hybrids. The experiments were disposed in randomized complete blocks, with fifteen treatments and four replications, by using factorial scheme 5x3, composed by sowing in 2,5; 5,0; 10,0; 15,0 and 20,0 cm depths with application in pre-emergency condition of the herbicides: trifluralin (1125 g a.i. ha-1), pendimethalin (1500 g a.i. ha-1) and check without herbicide (hand-hold check). Only the sowing depths of 2.5 and 20.0 significantly reduced the initial development of castor bean cultivars AL Guarany 2002 and Iris, without interfering in characteristics number of leaves, stem diameter, insertion height of first raceme and yield. Trifluralin application has increased significantly AL Guarany 2002 yield, in sowings from 5.0 cm deep, unlike Iris and Savana hybrids, where most of sowing depths studied, resulted in yield declines. Pendimethalin herbicide presented high selectivity mainly for AL Guarany 2002 and Savana cultivars, characterizing, generally as the safest option castor bean crop.Três experimentos foram conduzidos no município de Garça-SP com o objetivo de avaliar os efeitos da profundidade de semeadura em três cultivares de mamoneiras submetidas ou não à aplicação de herbicidas dinitroanilinas em pré-emergência. As três cultivares utilizadas foram a variedade AL Guarany 2002 e os híbridos Íris e Savana. Os experimentos foram dispostos em delineamento de blocos casualizados, com quinze tratamentos e quatro repetições, utilizando-se esquema fatorial 5x3, representado pela semeadura nas profundidades de 2,5; 5,0; 10,0; 15,0 e 20,0 cm na condição de aplicação em pré-emergência dos herbicidas trifluralin (1125 g i.a. ha-1), pendimethalin (1500 g i.a. ha-1) e testemunha sem herbicida e capinada. Apenas as profundidades de semeadura 2,5 e 20,0 cm reduziram significativamente o desenvolvimento inicial dos cultivares de mamoneira AL Guarany 2002 e Íris, sem interferir nas características número de folhas, diâmetro de caule, altura de inserção do primeiro racemo e produtividade. A aplicação de trifluralin incrementou significativamente a produtividade da variedade AL Guarany 2002, em semeaduras a partir de 5,0 cm de profundidade, ao contrário dos híbridos Íris e Savana, onde na maioria das profundidades de semeadura estudadas, ocorreram decréscimos de produtividade. O herbicida pendimethalin apresentou elevada seletividade principalmente para AL Guarany 2002 e Savana, caracterizando-se, de forma geral, como a opção mais segura para a cultura da mamona.

Este trabalho objetivou caracterizar biometricamente sementes e frutos de Hymenaea courbaril L. e determinar o grau de umidade, bem como avaliar diferentes tratamentos de superação de dormência. Foram determinados a biometria, a massa de frutos e sementes e o número de sementes por fruto. As sementes foram submetidas aos seguintescortes: 1-testemunha, sem escarificação ou corte; 2-escarificação em três faces; 3-corte ao meio e 4-corte em quatro partes. Avaliou-se também o percentual de emergência, o IVE, o comprimento da parte aérea e da raiz de plântulas. Para isso, as sementes foram submetidasà superação de dormência, com e sem embebição em água, pelos seguintes tratamentos: Iescarificação do lado oposto ao hilo; II-escarificação em uma lateral; III-escarificação em duas laterais; IV-escarificação em uma lateral e no lado oposto ao hilo; V-escarificação em duas laterais e no lado oposto ao hilo; VI-Testemunha, sem escarificação. O comprimento, a largura, o diâmetro e a massa média dos frutos foram 115,7 mm; 62,18 mm; 43,8 mm e 183,85 g, respectivamente. Para a determinação da umidade, deve-se cortar as sementes em pelo menos duas partes. A escarificação, independentemente da posição na semente, com ou sem embebição em água, possibilita maior qualidade fisiológica.This study aimed to characterize biometrical seeds and fruits ofHymenaea courbaril L., determine the moisture content and assess different treatments to overcome dormancy. Fruit biometry, mass of fruits and seeds, and the number of seeds per fruit were determined. The seeds were submitted to the following treatments: 1-control, without cutting or scarification, 2-scarification on three sides, 3-cut in half and 4-cut in four parts. The percentage of emergence, emergence speed index, length of the buds and root of seedlings werealso evaluated. So, the seeds were submitted to overcome dormancy, with and without soaking in water, represented by the following treatments: I-scarification on the opposite side of the hilum,II-scarification on one lateral side; III-scarification on two lateral sides; IV-scarification on one lateral side and on the opposite side of the hilum, V-scarification on two lateral sides and on the opposite side to hilum; VI-control without scarification. The length, width, diameter and the average mass of fruit were 115.7 mm; 62.18 mm, 43.8 mm and 183.85 g, respectively. For the determination of moisture, the seed should be cut in at least two parts. Scarification, regardless of position in seed, with or without soaking in water, allows greater physiological quality.

Debido al auge de la gulupa y a su importancia económica en Colombia, se hace necesario mejorar las técnicas de producción de este cultivo. La gulupa, se propaga, comercialmente, mediante semillas, pero la dureza e impermeabilidad de la testa origina problemas de germinación y de vigor germinativo, que complican las labores de propagación y la obtención uniforme de las plántulas. Con el fin de lograr material de buena calidad para transplante, en un diseño completamente al azar bifactorial de 4x2, se estratificaron semillas de gulupa a 4°C, durante 0, 360, 720 y 1440h, con cubierta plástica negra en la siembra y sin ella, durante 15 días, para un total de ocho tratamientos. La siembra, se realizó en bandejas de germinación de 72 alvéolos REF. A-BA72; el experimento tuvo una duración de 60 días y se llevó a cabo en condiciones de invernadero. La germinación, se activó solo con los tratamientos de 360 y 720h de estratificación y 15 días de cubrimiento con plástico negro, durante la germinación y 360h sin la puesta de plástico. Los mayores valores de porcentaje de emergencia, velocidad media de germinación y altura de planta, se observaron en el tratamiento de 360h de estratificación fría y 15 días de cubrimiento con plástico negro. Los tratamientos de frío y plástico negro son complementarios para una germinación óptima. Las semillas que permanecieron 720h en estratificación con 15 días de cubrimiento de plástico, durante la germinación, presentaron el mayor tiempo medio de emergencia, pero generaron las plántulas con mayor longitud de raíz.Due to the rise of purple passion fruit and its economic importance in Colombia it is necessary to improve the production techniques of this crop. The purple passion fruit is propagated commercially by seeds, but its coat is very hard, with a high impermeability causing problems for germination and germination forcing, which complicates propagation and seedlings uniformity. In order to achieve good quality material for transplantation, in a completely randomized bifactorial design of 4x2, purple passion fruit seeds were stratificated at 4°C for 0, 360, 720 and 1440 hours, covering with and without black plastic mulch at planting for 15 days, for a total of eight treatments. Seedlings were planted in trays of 72 cavities REF. A-BA72; the experiment lasted 60 days and was conducted under greenhouse conditions. Germination was activated only with the treatments of 360 and 720 h and 15 days of covering with black plastic and 360 h without black plastic. The highest germination percentage and average germination speed and plant height were observed in the treatment of 360 h stratification and 15 days of covering with black plastic. The combination of cold and black plastic is considered complementary for optimum germination. The seeds, 720 h stratificated, with 15 days covered with plastic showed the largest average emergency time, but generated seedlings with the largest main root.

Dentro de um programa de controle de qualidade, a avaliação do vigor de sementes é fundamental e necessária para o sucesso da produção. Com o objetivo de avaliar a eficiência de diferentes testes de vigor na avaliação da qualidade fisiológica de sementes de milho-doce na tentativa de diferenciação de lotes quanto ao nível de vigor e previsão de emergência de plântulas em campo e ao potencial de armazenamento, 10 lotes do híbrido DO-04 shrunken-2 (sh-2) foram submetidos a teste de germinação, primeira contagem, precocidade de emissão de raiz primária (32, 48, 56 e 72h), teste de frio, condutividade elétrica (50 sementes 75mL-1 de água; 25°C/4, 6, 8 e 24h), envelhecimento acelerado (42°C) em água destilada (100%UR), solução saturada de cloreto de potássio (87%UR) e solução saturada de cloreto de sódio (76% UR), avaliando-se quatro períodos de exposição (24, 48, 72 e 96h), teor de água, emergência de plântulas em campo e germinação após armazenamento das sementes (10°C e 40%UR), avaliada quadrimestralmente por 16 meses. A condutividade elétrica (por 6, 8 e 24h) foi o único teste eficiente na diferenciação do vigor de lotes de sementes de milho-doce (sh2); no entanto, não apresentou correlação com a emergência de plântulas em campo ou armazenamento.In a program of seed quality assurance, the evaluation of seed vigor is fundamental and necessary to the global production process outcome. The objective of this experiment was to verify the efficiency of different vigor tests for evaluation of sweet corn seeds quality towards lots differentiation and prevision of seedling emergence and storage capacity of those. Ten lots of DO-04 shrunken-2 (sh2) hybrid sweet corn seeds were submitted to the following evaluations: germination, first counting of germination test, earliness of primary root emission (32, 48, 56 and 72 hours), cold test, electrical conductivity test (50 seeds into 75ml of water, at 25°C for 4, 6, 8 and 24 hours), accelerated aging test (42°C) in distilled water (100% RH), potassium chloride saturated solution (87% RH) and sodium chloride saturated solution (76% RH). Four exposition periods (24, 48, 72 and 96 hours) were evaluated and also seed water content, field seedlings emergence and germination after seeds storage (10°C and 40%RH) during sixteen months. The electrical conductivity test (for 6, 8 and 24 hours) was the unique test efficient to distinguish vigor of sweet corn (sh2) seeds lots, but it did not present correlation with field seedlings emergence or storage capacity.

The objective of this work was to determine the effects of seed priming and sulfur application on cell membrane characteristics, seedling emergence, chlorophyll content and grain yield of soybean (Glycine max) in saline soil. A complete-block design in 4x3 factorial arrangement with three replicates was used to test four types of seed priming (water, auxin, gibberellin and non-priming) and three levels of sulfate availability (0, 70 and 140 kg ha-1 K2SO4). The soil had a silty loam texture with an electrical conductivity of 3.61 ds m-1, a pH of 8.2 and a saturation percentage of about 46%. Seed priming had significant effects on mean emergence rate (MER), emergence percentage, relative water content (RWC) of leaves, relative chlorophyll content, time of maturity, shoot length and grain yield. The highest values for these variables were observed in the priming treatments, except for the time of maturity. Sulfur application had significant effects on MER, shoot length, RWC, membrane injury index and grain yield. Priming treatments provide greater emergence rates and grain yields and interact sinergicaly with sulfur rates.O objetivo deste trabalho foi determinar os efeitos do condicionamento osmótico das sementes e da disponibilidade de enxofre sobre características da membrana celular, emergência de plântulas, conteúdo relativo de clorofila e produtividade de soja (Glycine max) em solo salino. O experimento foi conduzido em delineamento de blocos ao acaso, em arranjo fatorial 4x3, com três repetições, para avaliar quatro tipos de condicionamento osmótico das sementes (água, auxina, giberelina e ausência de condicionamento) e três níveis de disponibilidade de enxofre para as plantas (aplicação ao solo de 0, 70 e 140 kg ha-1 de K2SO4). O solo utilizado apresentava textura média, com condutividade elétrica de aproximadamente 3,61 ds m-1, pH de 8,2 e percentagem de saturação em torno de 46%. O condicionamento osmótico das sementes teve efeito significativo sobre a taxa média de emergência (MER), percentagem de emergência, conteúdo relativo de água das folhas (RWC), conteúdo relativo de clorofila, época de maturação, comprimento da parte aérea e produtividade de grãos. Os maiores valores para essas variáveis, exceto época de maturação, foram observados nos tratamentos com condicionamento osmótico. A aplicação de enxofre teve efeito significativo sobre MER, comprimento da parte aérea, RWC, índice de dano à membrana celular, e produtividade de grãos. O condicionamento osmótico proporciona maiores taxas de emergência e produtividade de grãos e interage significativamente com a aplicação de enxofre.

O presente trabalho teve por objetivo avaliar a embebição e a posição de semeadura no processo de germinação de sementes de cajueiro-anão-precoce, em condições de telado. O experimento foi conduzido na Fazenda Escola São Luís, da Universidade Estadual do Maranhão, São Luís-MA. Utilizou-se o esquema fatorial 2 x 3 x 2, no delineamento experimental em blocos casualizados e quatro repetições, com 15 sementes por parcela, semeadas em sacolas plásticas. Os tratamentos resultaram da combinação de dois clones (CCP .06 e CCP 76), três tratamentos de embebição (água, sacarose e natural ) e posição da semente (peduncular e dorsal) por ocasião da semeadura. Verificou-se que, aos 22 dias após a semeadura, o clone CCP 76, com as sementes embebidas em água e semeadas na posição peduncular, apresentou níveis satisfatórios de germinação (100%), resultando em maior eficiência do processo de germinação das sementes e precocidade em termos de estabilização da germinação (cerca de 16 dias). Os tratamentos de embebição com sementes na posição peduncular não apresentaram efeito significativo sobre a emergência das plântulas dos dois clones, mas influenciaram nos valores do índice de velocidade de emergência, onde os tratamentos com água e a posição peduncular proporcionaram maior velocidade de emergência, independentemente dos clones estudados.The present work aimed to evaluate the imbibition and the sowing position on the process of seed germination of dwarf cashew-precocious rootstocks. The experiment was carried out on São Luís Experimental Farm of the Maranhão State University, Brazil. The experimental model was a factorial design 2 x 3 x 2 in randomized blocks and four replications, with 15 seeds per plot, sowed in plastic bags. The treatments resulted from the combination of two cashew clones (CCP 06 and CCP 76), three treatments of imbibition (water, sucrose and natural) and seed position (hilo and dorsal) before sowing. According to the obtained results, it was verified that up to 22 days after sowing the clone CCP 76 with seeds soaked in water and sowed in the hilo position, presented satisfactory levels of germination (100%), resulting in larger efficiency of the seed germination process and precocity in terms of stabilization of the germination (about 16 days). The treatments of imbibition at hilo position did not present a significant effect on the seedlings emergence of two clones, but they influenced the emergence speed index, in which the treatments using water and hilo position promoted higer index, regardless of the tested clones.

Uniformity and percentage of seedling emergence of direct-seeded vegetables have a major impact on their yield and quality. Depending on temperature and soil water potential, carrot seeds performance in the field is poor justifying the use of techniques to accelerate the germination and seedling emergence. The objective of this work was to evaluate the effects of priming treatments, with and without aeration, on carrot seeds performance under water and temperature stress. Two seed lots of carrots, Brasília cultivar, were primed in PEG 6000 -1.0 and -1.2 MPa solutions, for four and eight days, at 20ºC, using two imbibition methods: priming in paper towel moistened with the respective solutions and immersion into aerated osmotic solutions. Non-primed seeds were used as control. After priming, the seeds were dried at room temperature until reach initial seed moisture content. The seeds were submitted to the following tests: germination, first count, seedling emergence in the field, germination at sub-optimal (15ºC) and supra-optimal temperature (30ºC) and germination under water stress (PEG 6000 at -0.4 MPa). Priming in -1.0 and -1.2 MPa PEG 6000 during four and eight days can be useful for improving carrot seedling emergence in the field and seed performance under supra and sub-optimal temperatures. Aeration of the peg solution was beneficial when seeds were primed at -1.2 MPa for eight days.Na cultura da cenoura são constantes os problemas relativos ao desempenho das sementes em campo, justificando técnicas que acelerem a germinação das sementes e a emergência das plântulas. O objetivo deste trabalho foi avaliar o efeito do condicionamento osmótico, com e sem uso de soluções aeradas, no desempenho de sementes de cenoura sob estresse hídrico e térmico. Para tanto, sementes de dois lotes, cv. Brasília, foram condicionadas em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, a 20ºC, utilizando-se dois métodos de embebição para o condicionamento: em papel toalha umedecido com as respectivas soluções e imersão em soluções osmóticas aeradas. Sementes não condicionadas foram utilizadas como testemunha. Após o condicionamento, as sementes foram secas em ambiente de laboratório até atingirem o grau de umidade inicial. Em seguida, foram avaliadas pelos seguintes testes: germinação, primeira contagem de germinação, emergência das plântulas em campo, germinação a temperatura sub (15ºC) e supra-ótima (30ºC) e germinação sob estresse hídrico (PEG 6000 a -0,4 MPa). O condicionamento osmótico das sementes de cenoura em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, é recomendado para aumentar a emergência de plântulas em campo e o desempenho sob temperatura sub e supra-ótima. O uso de soluções aeradas de PEG foi benéfico apenas quando as sementes foram condicionadas a -1,2 MPa por oito dias.

Native grasslands in the Campos de Cima da Serra, Brazil, are being converted at speed for exotic tree plantations and cropland. The impact of modified and novel soil conditions on the establishment of native grassland species is unknown; establishment of non-native species, deliberately or accidentally introduced, could be favoured. In a common garden composed of fully randomized replicate samples of soils collected from remnant grassland, former cropland and pine plantations, we tested emergence and establishment of five cold-season species: Native low-tussock grass Piptochaetium montevidense (Spreng.) Parodi; native legume Trifolium riograndense Burkart; naturalized low-tussock grass Vulpia bromoides (L.) Gray; low-tussock grass Holcus lanatus L., cultivated and naturalized in Brazil; and a cultivar of non-native Trifolium repens. Other than expected, soil type and species*soil type interactions had no significant effect on seedling emergence after 132 days in the field. Species effect on seedling emergence, however, was highly significant. Vulpia bromoides emergence was significantly highest in all soil types. Holcus lanatus and Trifolium riograndense both achieved second highest emergence rates and did not differ significantly from each other. Lowest overall emergence rates were found in the non-native clover cultivar. Lab germination tests failed for Piptochaetium, although it showed reasonable emergence in the field. Good performance of the native clover is encouraging for future grassland restoration, but the value of highly germinable Vulpia as a forage remains to be tested. Holcus tolerates a wide range of soil conditions and its life history traits may promote naturalization, or even invasiveness. Native grasslands of the region should be monitored for this species. Studies like these, but set up on a larger geographical scale and with a wider array of native species, will be essential in developing ecological restoration methods for southern Brazilian grasslands. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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The objective of this study was to evaluate the physiological potential of stylosanthes seeds cv. Campo Grande in response to coating with zinc and boron. The treatments were: T1 - uncoated seeds; T2 - seeds coated with calcium silicate; T3 - 80 g of B + 60 g of Zn.kg-1 seeds; T4 - 120 g of B + 90 g of Zn.kg-1 seeds; T5 - 160 g of B + 120 g of Zn.kg-1 of seed and; T6 - 200 g of B + 150 g of Zn.kg-1 of seed. The seeds were evaluated by germination test, speed index and mean time of germination (GSI and MGT), seedlings emergence test, speed index and mean emergence time (ESI and MET), shoot and root length (SL and RL), leaf area (LA), number of nodes (NN) and shoot and root fresh (SFW and RFW) and dry weight (SDW and RDW). Coating reduced the germination and seed vigor. Micronutrients favored plants development, after its establishment. The coating with 120 g of B + 90 g de Zn.kg-1 of seed favors the growth, development and nodulation of the plants. [ABSTRACT FROM AUTHOR]

O objetivo deste trabalho foi avaliar a influência do envelhecimento precoce no vigor de sementes de paineira (Chorisia speciosa St. Hil. - Bombacaceae). Adotou-se o método da câmara de envelhecimento (45ºC e 100% de umidade relativa), sendo utilizadas para cada período de envelhecimento (0, 24, 48, 72, 96, 120 e 144 horas) quatro subamostras de 50 sementes, distribuídas em caixas tipo ";gerbox";. Decorridos os períodos de envelhecimento, as sementes foram submetidas às seguintes avaliações: teste de germinação (27 ºC), teste de condutividade elétrica e avaliação de plântulas. Os resultados foram submetidos à análise de variância e ao teste de Tukey. Nos períodos de 48, 72, 96 e 120 horas de envelhecimento, foram obtidos valores estatisticamente inferiores de porcentagem de germinação em relação ao experimento-controle. A permanência das sementes por 144 horas em câmara de envelhecimento levou à perda total da viabilidade. O decréscimo na germinação foi diretamente proporcional ao aumento na lixiviação eletrolítica dos solutos celulares das sementes. A partir de 72 horas de envelhecimento precoce, detectou-se redução significativa na porcentagem de plântulas emergidas. O período de 72 horas de envelhecimento mostrou-se adequado para ser utilizado em trabalhos futuros de avaliação de vigor de sementes de paineira, pois é possível detectar diferenças significativas, em relação ao experimento-controle (sementes não envelhecidas), dos parâmetros porcentagem de germinação, porcentagem de plântulas emergidas e condutividade elétrica.The aim of this work was to evaluate the effects of accelerated aging on the seed vigor of paineira (Chorisia speciosa St. Hil.- Bombacaceae). The aging chamber technique was used (45ºC and 100% R.U.) and four replications of 50 seeds were distributed on gerbox for each aging time (0, 24, 48, 72, 96, 120 and 144h). After the aging periods, the seeds were submitted to germination test (27ºC), electric condutivity, percentage of seedling emergence,and seedling dry matter. The results were submitted to analysis of variance and Tukey test. The germination percentages after 48, 72, 96 e 120h of accelerated aging was smaller than in the control group. Viability was lost after 144h within the chamber. The decrease in germination percentage was directely related to solute leakage from seed cells. A significant decrease in seedling emergence occurred after 72h of exposure to accelerating aging. The period of 72h inside the chamber may be recommended for seed vigor evaluation, because significant differences between the control group and the aging seeds were found for percentage of germination, seedling emergence and electric conductivity.

Los objetivos del trabajo fueron evaluar el efecto del tratamiento con productos químicos y contenido de humedad en la conservación de semillas de mandarino 'Cleopatra' (Citrus reshni Hort ex Tan). Semillas con 14,7% de humedad tratadas con cuatro funguicidas y 8-hidroxiquinoleina, fueron almacenadas a 4±2°C durante un año, al igual que tres lotes de semillas con 5,0%, 14,7% y 26,8% de humedad, tratadas con y sin 8-hidroxiquinoleina. Se evaluó la germinación y emergencia al inicio del experimento, a los seis y 12 meses de almacenamiento. En la prueba con productos químicos, el almacenamiento de semillas con 14,7% de humedad sólo fue viable hasta los seis meses, con mayores porcentajes de germinación y emergencia (59,3% y 54,0%, respectivamente), mientras que, en las semillas sin tratamiento químico fue de 33,3% y 27,3%, respectivamente. En relación con el contenido de humedad de las semillas, a los seis meses de almacenamiento se obtuvo mayor emergencia de plántulas (63,6% y 58,0%) en semillas con 26,8% y 5%, mientras que a los 12 meses, las semillas con 5%, de humedad tuvieron 75,6% de emergencia.The objetives of this work were to evaluate the effect of the treatment with chemical products and the humidity content for conservation of seeds of 'Cleopatra' mandarin (Citrus reshni Hort ex Tan). Seeds with 14.7% of moisture content were treated with four fungicides and 8-hydroxyquinoline and stored at 4±2°C for one year. Three groups of seeds with 5.0, 14.7% and 26.8% of moisture content were stored as above. Germination and emergence were evaluated at the beginning of the two experiments, at six and twelve months of storage. In the test with chemical products, storage of seeds with 14.7% of moisture content was possible only for six months, with higher percentages of germination and emergence (59.3% and 54.0%, respectively), while in seeds without chemical treatment percentages of germination and emergence were about 33.3% and 27.3%, repectively. As far as the moisture content of the seed is concerned, at six months of storage the highest seedlings emergence (63,6% and 58.0%) were obtained, in seeds with 26.8% and 5% of moisture, respectively. Twelve-months-seeds with 5% of moisture content caused 75.6% of emergence.

Para determinar a dose máxima de cobre que pode ser aplicada às sementes de milho sem provocar danos à emergência, realizou-se um experimento, em condição de casa de vegetação, em delineamento inteiramente casualizado, um teste de emergência. As sementes de milho foram tratadas com uma solução de sulfato de cobre nas dosagens de: 0,00; 1,00; 2,00; 4,00 e 6,00g de cobre por kg de sementes. A aplicação de cobre nas sementes de milho prejudicou a emergência das mesmas e a dose de 5,09g de cobre por kg de sementes foi a que mais influenciou negativamente nesta variável. A partir do tratamento com 4,00g de cobre por kg de sementes, sintomas de toxicidade foram observados sem afetar a massa seca das plantas.

Conduziu-se este trabalho com o objetivo de avaliar a eficiência dos fungicidas fludioxonil + metalaxyl-M no controle de fungos associados às sementes de sorgo da cultivar BR 506 e na proteção delas contra fungos do solo. Assim, sementes de sorgo foram tratadas com os seguintes fungicidas (dose em g i.a./100 kg sementes): fludioxonil + metalaxyl-M (2,5 + 1,0), fludioxonil + metalaxyl-M (3,75 + 1,5), fludioxonil + metalaxyl-M incolor (2,5 + 1,0), fludioxonil + metalaxyl-M incolor (3,75 + 1,5) e thiram (140,0). Sementes sem tratamento fungicida constituíram a testemunha. Foram avaliadas as seguintes características: sanidade das sementes (papel de filtro com congelamento), emergência de plântulas em solo esterilizado (casa-de-vegetação), emergência em solo com monocultivo de sorgo (casa-de-vegetação) e emergência no teste de frio em solo com monocultivo de sorgo (laboratório e casa-de-vegetação). Pelas análises dos resultados (Tukey a 5 %), constatou-se que: 1- O fungicida thiram foi eficiente no controle de Fusarium subglutinans associado às sementes de sorgo, porém, ineficiente no controle de Aspergillus spp.; 2- Os fungicidas fludioxonil + metalaxyl-M, fludioxonil + metalaxyl-M incolor e thiram foram eficientes no controle de Penicillium spp., Alternaria tenuis, Phoma sorghina, Curvularia lunata e Drechslera turcica; 3- Todos os tratamentos fungicidas das sementes incrementaram, em solo esterilizado, a emergência de plântulas de sorgo devido ao controle dos fungos patogênicos associados às sementes, e 4- Todos os tratamentos fungicidas incrementaram, em solo com monocultivo de sorgo, a emergência de plântulas, pela proteção das sementes de sorgo contra fungos de solo.This work was carried out in order to evaluate the efficiency of several fungicides applied as seed dressing in the control of sorghum seedborne fungi and the protection against soilborne fungi. Sorghum seeds of cultivar BR 506 were treated with the following fungicides (doses in g a.i./100 kg of seeds): fludioxonil + metalaxyl-M (2.5 + 1.0), fludioxonil + metalaxyl-M (3.75 + 1.5), colorless fludioxonil + metalaxyl-M (2.5 + 1.0), colorless fludioxonil + metalaxyl-M (3.75 + 1.5) and thiram (140.0). Seeds without fungicide treatment constituted the check. The following characteristics were evaluated: seed health (deepfreezing method), seedling emergence in sterile soil (green house), seedling emergence in sorghum monocropped soil (green house) and cold test in sorghum monocropped soil (laboratory and green house). The analyses of the results (Tukey at 5%) showed that: 1- the fungicide thiram was effective in the control of Fusarium subglutinans associated to the sorghum seeds, but ineffective against Aspergillus spp.; 2- fungicides fludioxonil + metalaxyl-M, colorless fludioxonil + metalaxyl-M and thiram were effectively in the controlled Penicillim spp., Alternaria tenuis, Phoma sorghina, Curvularia lunata and Drechslera turcica; 3- all fungicides had a positive effect on seedling emergence due to the protection against pathogenic fungi associated to sorghum seeds, and 4- all the fungicide treatments increased the seedling emergence in sorghum monocropped soil due to protection of seeds against soilborne fungi.

The objective was to assess the early treatment effect of soybean seeds and pre-sowing with different combinations of chemicals on the establishment of plants and crop yield performance. The design was in randomized blocks in a 2x7 factorial arrangement, with two times for seed treatment and seven treatments (six chemical treatments and an untreated control). The treatments were: 1) fipronil + pyraclostrobin + thiophanate methyl; 2) imidacloprid + thiodicarb + carbendazin + thiram; 3) abamectin + thiamethoxam + fludioxonil + mefenoxam + thiabendazole; 4) carbendazin + thiram; 5) fludioxonil + mefenoxam + thiabendazole; 6) carboxin + thiram; and 7) untreated control (water only). The assessments were: seedling emergence, final stand, plant height and insertion of first pod, number of pods per plant, seeds per pod and per plant, thousand-seed weight and grain yield. Early treatment of soybean seeds (240 days prior to sowing) hinders the establishment of the crop, the thousand-seed weight and grain yield in relation to the pre-sowing treatment. Chemical treatments tested containing fungicides and insecticides associated favor the establishment of the crop, but do not alter the soybean yield performance. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the floristic composition of the seed bank in the soil and litterfall at different stages of natural regeneration in areas of Caatinga. The study was conducted at Farm Cachoeira of São Porfírio, in the municipality of Várzea, PB, where four were select areas, one with native pasture and three in different stages of natural regeneration. For sampling the seed bank were randomly collected 144 samples, and the methodology used to determine the floristic species composition of the seed bank was of seedling emergence and recognition in herbarium. To assess the floristic diversity were estimated index of diversity Shannon-Weaver (H'), the index Pielou evenness (J'), and similarity of Jaccard (Sj). The floristic composition of the seed bank of the study area is represented by 94 species belonging to 71 genera, distributed in 29 botanical families. The seed bank of the four study areas consists predominantly of species of herbaceous habit and floristic composition varies according to the stage of natural regeneration, being higher in more advanced stages. [ABSTRACT FROM AUTHOR]