Frugivoria e dispersão de sementes de Talauma ovata (Magnoliaceae) no sudeste brasileiro

Some plants are widely distributed, ranging in different vegetation types. Since bird distribution can be directly associated to vegetational cover, we expect that seed dispersers can also vary following phytophysiognomy for some ornithochorous plants. The purpose of this paper was to describe potential seed disperser birds of Talauma ovata (Magnoliaceae) in semideciduous Atlantic forest and cerrado fragments in south-east Brazil. In 79 h of focal observations we recorded 1085 visits of 25 different bird species consuming T. ovata diaspores. Although most bird species observed consuming T. ovata diaspores present generalist habits, they were potential seed dispersers, presenting high visits rate and do not staying a long time on the plants, favoring seed dispersal efficiency. Fruit consumption was not different between species in the study sites and the time spending on the plants was not different between species in semideciduous forest, but was different in cerrado. Agonistic encounters were observed mainly in the end of fruiting season, but was not relevant to decrease the number of seeds dispersed by birds. The occurrence of different potential seed dispersers between areas, such as Cyanocorax cristatellus (Corvidae), Schistochlamys ruficapillus (Emberizidae) and Mimus saturninus (Mimidae), which are endemic from the cerrado ecosystem and could rarely be found in semideciduous forest, suggests that seed dispersers can vary according to phytophysiognomy characteristics. Our results also indicate that the evolution of a generalist seed dispersal system such as observed for T. ovata can make possible the colonization of different ambients. Furthermore, the high number of visits recorded for both areas suggests that the fleshy arils of T. ovata are important feeding resources for birds.

Doses e épocas de aplicação de nitrogênio no feijoeiro irrigado cultivado em plantio direto

The nitrogen is the nutrient required in greatest quantities by the bean crop and the response to its application depends on the applied N rate as well as the time of its application. The objective of this work was to evaluate yield components, grain productivity and physiological quality of bean seeds, affected by different nitrogen (urea) rates top-dressed at three crop growth stages. The experiment was conducted in no-till system. The treatments were constituted by 0, 40, 80, 120, 160, 200 and 240 kg ha-1 N top-dressed at V4-5, R5 and R6 growth stages, corresponding to 21, 32 and 38 days after plant emergence, respectively. Seed physiological quality was evaluated by germination and vigor tests. Nitrogen applied at different crop growth stages did not interfere on the yield components, but interfered on bean productivity. Maximum grain productivity was obtained with top-dressed 164 kg ha-1 N, independently of growth stage application. Seed physiological quality was not affected by the treatments, fitting in the category of seeds for commercialization.

Maturidade fisiológica das sementes do ipê amarelo, Tabebuia chrysotricha (Mart. Ex DC.) Standl

Ipê amarelo Tabebuia chrysotricha (Mart. Ex DC.) Standl. is a native forest species that presents heavy and durable wood: it is common to be used for urban arborization. The species is latte secondary and heliophyta. Occurs from Espirito Santo State until Santa Catarina in the Pluvial Atlantic Forest (Mata Atlântica). The seedling production is hard because their seeds have short longevity after dispersion, and so due to the difficulty to harvest winged seeds that are quickly dispersed by the wind. The present study was carried out to evaluate the physiological maturity of Ipê Amarelo seeds, to establish the best moment to harvest them. The study was to accompany the maturation of 100 fruits in just beginning development, from eleven different trees. Morphological characteristic measures were made weekly, with fruits still on trees, starting from the second week development when fruits presented the following averages: 6.3 cm length, 0.71 cm thickness, and 0.82 cm width. From the sixth week of fruit development we harvest them to proceed the germination test, water content rate, and electric conductivity test. The germination has begun by the seventh week development with 28% of germinated seedlings. The highest germination rate happened by the eighth week development, with 74.5% of germinated seedlings and on the ninth week the rate decrease to 65.5%, when the seeds were already in dispersion. Through the electric conductivity test the highest value obtained was 378.06 μS.g -1.cm -1 on the seventh week development and the lowest one was 183.28 μpS.g -1.cm -1 on eighth week. These results support those obtained in the germination test, because as higher is the electric conductivity of seeds, as higher is their deterioration level. Finally, the study allows concluding that the physiological maturation of ipê amarelo seeds has occurred before dispersion close to the eighth week development when fruits presented the following averages: 22.2 cm length, 1.37 cm width, and 1.05 cm thickness; water content rate was 61.8% and electric conductivity was 183.28 μS.g -1.cm -1. In that moment, the fruits presented greened brown coloration and started to show fissures.

Avaliação de genótipos de soja em semeadura de inverno, em Selvíria, MS: Produção e qualidade fisiológica de sementes

The sowing of soybean out of the conventional period is an option for the production of seeds with high physiological quality. On the other hand, this fact makes necessary the search for cultivars adapted to new environmental conditions. Therefore, additional research is needed to supply more information to producers related to the choice of the most suited cultivars with regard to high seed quality. This research was conducted in Selvíria, MS, Brazil in which the cultivars FT-2000, FT-Inaê, Embrapa 20 (Doko RC), CAC-1, IAC-17, IAC-18, IAC-19, IAC-8-2, FT-101, FT-109, MT/ BR 45 (Paiaguás), MT/BR 50 (Parecis), MT/BR 52 (Curió), MT/BR 53 (Tucano), MT/BR 47 (Canário), MT/BR 49 (Pioneira), BRSMT Uirapuru, BR Emgopa 314 (Garça Branca), MG/BR 46 (Conquista), FT-Estrela, FT-Cometa, Dourados, JAB-11, BR 9 (Savana), FT-Abyara, Embrapa 30 (Vale do Rio Doce), Embrapa 9 (Bays), Embrapa 31 (Mina), IAC-16; IAS 5, EMGOPA-304, and IAC-Foscarin 31 were studied. These cultivars were sown on June 5, 1998, and evaluated both for agronomic characteristics and the physiological potential of the seeds. The experimental units were arranged in the field according to a randomized complete block design with five replicates. The cultivars more adapted to the climatic conditions were Parecis, Bays, CAC-1, Garça Branca, Paiaguás, Pioneira, and IAC-16. It was concluded that winter sowing should start at the beginning of May, with water supply, since June was found to be too late.

Germinação de sementes de pinho-cuiabano sob deficiência hídrica com diferentes agentes osmóticos

The species Schizolobium amazonicum (Huber ex Ducke) commonly known as pinho-cuiabano or paricá, is one of the trees in Amazonian area used for plantings in degraded areas, reforestations and agroforestry systems. The present work evaluated the germinative behaviour of seeds of Schizolobium amazonicum in relation to the hydric stress, defining their levels of tolerance to those limitations in the environment. The seeds were collected from 30 trees in Alta Floresta-MT and submitted the dormancy treatment by submersion into water at 100°C for 1 minute; followed by treatment with fungicide Ridomil and Cercobin 0,25% each, then being left to germinate in a BOD camera at 30°C under a photoperiod of 12 hours. For evaluating the effect of different water potentials in the germinative process, polyethylene glicol (PEG 6000) was used and the salts NaCI and CaCl 2 used to simulate saline stress. The seeds were put to soak in potentials of 0 (control); -0.1 ; -0.2; -0.3; -0.4 and -0.5MPa. For each treatment 5 repetitions of 20 seeds were used in gerbox, placed between filter paper moistened with 20 mL of PEG, NaCI and CaCl 2 solutions. The solutions were changed at intervals of 24 hours for maintenance of the potential. The evaluations of percentages and germination speed were carry out daily for 8 days, being considered germinated the seeds that presented a 2mm root extension or longer. The data were submitted to analysis of variance and averages compared by the Tukey test at 5% probability. It was concluded that osmotic potentials between -0.4 and -0.5MPa inhibited the germination of seeds of Schizolobium amazonicum completely. The osmotic stress caused by CaCl 2, and PEG injured the germination more than did the stress caused by NaCl.

Variação genética para compostos bioquímicos em sementes de duas populações naturais de Genipa americana L.: 1-análises individuais e univariada

Brazil is one of the world's richest countries in forest biodiversity. This has a great importance for humanity for sheltering essential scientific potential for the improvement in the quality of living beings. It also contributes to the preservation of natural resources and the environment. Among Brazil's forest species, jenipapo (Genipa americana L.) is commonly found in riparian vegetation. The objective of this work was to quantify the genetic variability of biochemical traits of seeds, as a support for in situ and ex situ conservation of natural populations of G. americana L. Two populations of the species were studied: one from Ilha Solteira, SP region (ISA) and other from Mogi Guaçu, SP (MOG). In the ISA population, seeds were collected from 30 trees, and in the MOG population, from 22 trees. These seeds were analyzed for chemical composition: content of proteins, carbohydrates, lipids and starch. The two populations of G. americana studied had a great genetic variation for these traits. The population ISA had an additive and phenotypic correlation, which was negative and high for starch with lipid; and positive and medium, for lipid with prolamine, as well as for globulin with prolamine. The population MOG presented additive and phenotypic correlations: positive and medium for gluteline with globulin. In these populations, narrow sense heritability estimates of progenies were moderate (0.69 for carbohydrates in the population ISA) to high (0.81 to 0.99 for the other traits in the two populations), indicating that much progress can be expected with selection strategies.

Qualidade fisiológica e sanitária de sementes de mamona submetidas a diferentes tratamentos químicos

The use of fungicides for treating seeds has become an essential measure in the control of pathogens. However, the effectiveness of many products is not well-known to some crops. The objective of this research was to evaluate the effect of different doses of carbendazin and carboxin + thiram fungicides for controlling pathogens and their interference on the physiologic quality of castor bean seeds. The test consisted of the following treatments (g i.a./100 kg of seeds): carbendazin (15, 30, and 60), carboxin + thiram (25 + 25, 50 + 50, and 100 + 100), formol 0.15% (v/v), and control (distilled water). The physiologic quality of the seeds was determined by germination, first counting, field emergence, speed emergence index, length, fresh and dry weight of the aerial part, and electrical conductivity. There were no statistical differences for germination and fresh and dry matter index. The treatment with formol provided lower values for first counting and field emergence. Seeds treated with fungicides presented higher values for electrical conductivity, but did not differ, statistically, among themselves. The fungi Cladosporium spp.; Bipolaris spp.; Curvularia spp.; Aspergillus flavus; Aspergillus niger; Rhizopus sp.; Penicillium sp.; Rhizoctonia sp.; Verticillium sp.; Fusarium sp.;Arthrobotrys sp.; and Epicocum sp. were identified. All tested products, independently of the dose, provided efficient control for pathogens.

Eugenia dysenterica DC: Actividad antioxidante, Perfil de ácidos grasos y determinación de tocoferoles

This work aimed to characterize the proximate composition, antioxidant activity and fatty acids profile and tocopherol composition of the oil from Eugenia dysenterica DC seeds. To obtain the extract, the dehydrated and triturated seeds were extracted with ethyl alcohol for 30 minutes, at a proportion of 1:3 of seeds:ethyl alcohol, under continuous agitation at room temperature. Afterwards, the mixture was filtered and the supernatant was dehydrated at 40°C in order to determine by direct weighing the dry matter yield of the extract. The cagaita seeds showed to be an important source of total carbohydrates, had relevant antioxidant activity and a high content of total phenolic compounds. In comparison to other oils and fats, cagaita seeds oil do not constitutes a good source of tocopherols.

Custo de produção e indicadores de rentabilidade da cultura do milho safrinha

The objective of this study was to evaluate the production cost and profitability of the second season corn crop in the Medio Paranapanema region, São Paulo State Brazil, under two technological levels (middle and high technology), crop 2008/2009, and compare the results with the 2006/2007 agricultural year. Effective and total operational cost as well as five profitability indicators were used. It was concluded that the high technology production cost for corn crop (direct seedling, sowing during the recommended period, use of simple hybrid seed, application of side-dressing fertilization, and treatment of seeds with different insecticides) was superior to the middle technology production cost (direct seedling, sowing after the recommended time, use of double hybrid seed, and no side-dressing fertilization). However, the average cost was inferior (US$ 8.5), due to a higher yield (4 t). The high technology corn crop was profitable (gross income and profitability index of 14% and 12%, respectively). For the middle technology crop, profitability indexes pointed out that the cropping system needs to be reevaluated by technicians and research institutions, regarding the adequate technical recommendations. Profitability indexes decreased considerably in both cropping systems. It was verified that, in relation to the 2006/2007 harvest period, the total operational cost increased for both technologies, mainly because of the increase of supplies prices.

Emergência de plantas daninhas em função da posição da semente e quantidade de palha de cana-de- açúcar

This work was carried out to evaluate the effects of sugarcane straw density and positions of seeds of Euphorbia heterophylla, Mucuna cinereum, Digitaria nuda and Eleusine indica on emergence and initial development of plants. The experiment were arranged in a completely randomized design, with 15 treatments and four replications, in a factorial arrangement 3 x 5 with a additional control; the first factor was constituted by position of seeds related to the straw (under, between and on) and the second by five quantities of straw (1, 2, 4, 8 e 16 t ha -1) with a control without straw. At 15 days after sowing (DAS) it was realized evaluations of height, dry mass and emergence percentage for E. heterophylla and M. cinereum, and at 28 DAS it was analyzed dry mass and emergence percentage for D nuda e E. indica. Data obtained were submitted to F in variance analysis test and means were compared with Tukey at 5% probability. Emergence and initial development of E. heterophylla e M. cinereum were reduced with increasing of straw and were affected by seed position, but it was not inhibited in none of conditions, indicating aggressiveness of these weeds in sugarcane mechanized harvest conditions. D. nuda and E. indica emergence was not affected by seed position and coverage soil with 8 e 16 t ha -1 of sugarcane straw inhibited its emergence.

Actividad antioxidante y perfil de ácidos grasos de las semillas de jabuticaba (Myrciaria cauliflora Berg)

Numerous natural compounds found in fruits, grains and vegetables have antioxidant activity. This work aimed to characterize jabuticaba seeds (Myrciaria cauliflora Berg) by proximate composition, antioxidant activity and fatty acids profile of their extracted oil. To obtain the extract, the dehydrated and triturated seeds were extracted with ethyl alcohol for 30 min, at a proportion of 1:3 of seeds:ethyl alcohol, under continuous agitation, at room temperature. Afterwards, the mixture was filtered and the supernatant dehydrated at 40 °C aiming to determine, by direct weighing, the extract's dry matter yield. According to the results, the jabuticaba seeds are an important source of total carbohydrates, and also presented relevant antioxidant activity. In the jabuticaba seeds oil, a significant percentage of polyunsaturated fatty acids stood out, with linoleic and α-linolenic being the main component, essentials fatty acids.

Germinación de semillas después del fuego: Un estudio con una planta que habita áreas no propensas al fuego

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tempo de passagem de sementes pelo trato digestório de aves frugívoras, uma primeira avaliação no Brasil

The transit time of seeds ingested by frugivorous animals has important implications for the spatial distribution of seeds and their dispersal distance. Nevertheless, this parameter is rarely included in seed dispersal studies. In this paper, we provide information about the transit time of seeds of nine species of plants ingested by individuals of six species of captive birds (Turdus albicollis, T. amaurochalinus, T. leucomelas, T. rufiventris, Stephanophorus diadematus and Saltator similis). We found that (1) seeds are regurgitated quickly through the digestive tract of birds than defecated seeds, and (2) large seeds (e.g., > 5 mm in diameter for Turdus spp.) are regurgitated rather than defecated. These results corroborate other studies, but the relationship between seed size and transit time seems to be quite complex and variable, requiring more detailed studies on this important aspect of the ecology of seed dispersal and digestive physiology of frugivorous birds.

Mastigação simulada e digestão ácido-enzimática de sementes de leguminosas forrageiras tropicais

This study aimed to evaluate the effect of simulated chewing in the laboratory on the survival of seeds of four tropical forage legumes (butterfly pea, Clitorea ternatea; estilosantes, Stylosanthes capitata/S. macrocephala 'Campo Grande; archer, Macrotyloma axillare and perennial soybean, Neonotonia wightii) submitted to different periods of acid enzymatic digestion in vitro. Three trials were conducted to observe the percentage of destroyed seeds by the mastication; to compare the germination of the seeds (intact seeds, simulated mastication, scarification with sandpaper, mastication and scarification with sandpaper). And, finally the seeds were incubated at 39oC with hydrochloric acid and pepsin for: 0, 2, 4, 8, 12 and 24 hours. The percentages of not destroyed seeds in mastication (archer, 91,5; perennial soybean, 88.0; butterfly pea, 82.1, and estilo, 81.1), associated with the beneficial effects of scarification on germination (64.7, 60.0, 92.0 e 87.3%, respectively) and the effects of time of acid-enzymatic digestion (75% higher if they stay 24 hours in HCl + pepsin) associated to the hard and not permeable coats of legume seeds, allow a high potential for resistance, and to pass intact through the digestive tract of cattle, being able to germinate when defecated in the pastures. However, estilo should not be included in the feeding of cattle for this purpose, because it do not resists the acid-enzyme digestion.

Caracterização morfométrica de sementes e plântulas e germinação de anadenanthera macrocarpa (benth.) brenan

Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family Leguminosae-Mimosoideae which is popularly known as mimosa-black. It features characteristics of early successional, natural occurrence in Brazil and can form clusters almost homogeneous, with great potential in the recovery of degraded areas. This study was conducted at the Center for Agricultural Sciences, University Federal of Alagoas state, aiming at the physical and morphological characterization of seeds, describing the various stages of post-seminal development, and to evaluate various conditions of temperature and substrate to perform the test germination. The seeds were manually extracted, then homogenized, where two samples of 50 seeds were used to determine the initial moisture. Another sample, consisting of eight repetitions of 100 seeds was used to measure the biometry and the number of seeds per fruit. The morphological characterization and the seeds were immersed in distilled water to allow the cuts to the observed structure in microscopes. In the post-seminal study, it was observed the daily processes of seedling growth in rolled paper filter and constant temperature of 30 °C. To assess the germination behavior, the constant temperatures of 15 °C, 25 °C, 30 °C, 40 °C and 20-30 °C as well as the paper and the sand substrates were tested and it was evaluated the percentage, the rate of germination, the relative frequency distribution, and the tests conducted in a randomized design in factorial 5 x 2 (x substrate temperature) with four replicates of 25 seeds, and the averages compared by Duncan 5 % probability. The fruits of black angico show great variation in the seed number per fruit. The embryonic axis occupies part of the central region of the seed with axial and linear positions. The germination is epigeal and the seedlings are fanerocotylar. The temperature determines the 30 °C and the filter paper substrate provided higher average percentage and germination rate.