Quantitative characteristics of fruits and seeds of Pouteria pachycarpa Pires - Sapotaceae

Pouteria pachycarpa is a tree species, found in the Brazilian Amazon and Bolivia whose wood has been exploited from the native forest. The present research describes the quantitative characteristics of fruits and seeds and quantifies the seed germination of this species. The fruit and seed color were characterized and measurements taken of the mass, length, diameter and number of seeds per fruit, the seed length, width and thickness, the germination percentage, abnormal seedlings and dead seeds. Sowing was carried out on a substrate containing sand and sawdust (1:1), in four replications of 50 seeds. The predominant fruit and seed colors were vivid yellowish orange (9YR) and dark grayish brown (6YR), respectively. Fruit mass, length and diameter ranged from 37.7 to 192.4g, 41.3 to 87.3mm and 39.7 to 71.7mm, respectively. Fruits had from two to seven seeds, and 42.6% were damaged by insects. Seed length, width and thickness ranged from 22.4 to 35.2mm, 9.7 to 15.5mm and 5.5 to 10.8mm, respectively. Seedling emergence began 18 days after sowing. Maximum germination, 86%, was recorded 33 days after sowing. The germination curve was sigmoid, similar to the majority of species. The percentage of abnormal seedlings and dead seeds were 3% and 11%, respectively. Both fruits and seeds show great variation in quantitative characteristics and the germination is slow and non-uniform.

Methods of overcoming dormancy in Schizolobium amazonicum Huber ex Ducke (Leguminosae - Caesalpinioideae) seeds

Seed dormancy is a frequent phenomenon in tropical species, causing slow and non-uniform germination. To overcome this, treatments such as scarification on abrasive surface and hot water are efficient. The objective of this study was to quantify seed germination with no treatment (Experiment 1) and identify an efficient method of breaking dormancy in Schizolobium amazonicum Huber ex Ducke seeds (Experiment 2). The effects of manual scarification on electric emery, water at 80ºC and 100ºC and manual scarification on wood sandpaper were studied. Seeds were sown either immediately after scarification or after immersion in water for 24h in a sand and sawdust mixture. Germination and hard seed percentages and germination speed were recorded and analyzed in a completely randomized design. Analysis of germination was carried out at six, nine, 12, 15, 18, 21 and 24 days after sowing as a 4x2 factorial design and through regression analysis. Treatment means of the remaining variables were compared by the Tukey test. Seed germination with no treatment started on the 7th day after sowing and reached 90% on the 2310th day (Experiment 1). Significant interaction between treatments to overcome dormancy and time of immersion in water was observed (Experiment 2). In general, immersion in water increased the germination in most evaluations. The regression analyses were significant for all treatments with exception of the control treatment and immersion in water at 80ºC. Germination speed was higher when seeds were scarified on an abrasive surface (emery and sandpaper) and, in these treatments, the germination ranged from 87% to 96%, with no hard seeds. S. amazonicum seeds coats are impermeable to water, which hinders quick and uniform germination. Scarification on electric emery followed by immediate sowing, scarification on sandpaper followed by immediate sowing and sowing after 24h were the most efficient treatments for overcoming dormancy in S. amazonicum seeds.

Using X rays to evaluate fissures in rice seeds dried artificially

The objective of the present study was to evaluate the efficiency of X-rays in identifying fissures in artificially dried rice seeds and the relationship between damage and seed performance in the germination test. Irrigated rice seeds of the IRGA 417 and IRGA 420 cultivars were harvested with 23.3 and 24.5% water content respectively and submitted to stationary drying treatments at 32, 38, 44 and 50 °C. X-rays were taken of subsamples of 100 seeds for each treatment, using an MX-20 X-ray equipment. The X-rayed seeds were classified from 1 to 3, where 1 corresponded to seeds without fissures, 2 to seeds with non-severe fissures and 3 to seeds with severe fissures. The same X-rayed seeds were planted and on the seventh day the seedlings (normal or abnormal) and dead seeds were photographed and evaluated to verify any relationship between the fissures and physiological potential. Higher drying temperature increased the percentage of fissures in the two cultivars, which can adversely affect their germination. Seeds with fissures can be identified using X-rays.

X-Ray analysis to assess mechanical damage in sweet corn seeds

The X-ray test is a precise, fast and non-destructive method to detect mechanical damage in seeds. In the present study, the efficiency of X-ray analysis in identifying the extent of mechanical damage in sweet corn seeds and its relationship with germination and vigor was evaluated. Hybrid 'SWB 551' (sh2) seeds with round (R) and flat (F) shapes were classified as large (L), medium (M1, M2 and M3) and small (S), using sieves with round and oblong screens. After artificial exposure to different levels of damage (0, 1, 3, 5 and 7 impacts), seeds were X-rayed (15 kV, 5 min) and submitted to germination (25 °C/5 days) and cold (10 °C/7 days) tests. Digital images of normal and abnormal seedlings and ungerminated seeds from germination and cold tests were jointly analyzed with the seed X-ray images. Results showed that damage affecting the embryonic axis resulted in abnormal seedlings or dead seeds in the germination and cold tests. The X-ray analysis is efficient for identifying mechanical damage in sweet corn seeds, allowing damage severity to be associated with losses in germination and vigor.

Physiological quality of coffee seeds produced under different levels of solar radiation and maturation stages

In Brazil, although the coffee plantations are predominantly grown under full sunlight, the use of agroforestry systems can lead to socioeconomic advantages, thus providing a favorable environment to the crop by promoting its sustainability as well as environmental preservation. However, there is a lack of information on physiological quality of the coffee seeds produced under different levels of solar radiation. Within this context, the objective of this study was to evaluate the influence of different levels of solar radiation and maturation stages on the physiological quality of coffee (Coffea arabica L.) seeds, cv. Acaiá Cerrado MG-1474. Three levels of solar radiation (plants grown under full sunlight; under plastic screens of 35% shading; and under plastic screens of 50% shading) and three maturation stages (cherry, greenish-yellow and green) were assessed. Physiological quality of seeds was assessed by using germination test, first count of germination, abnormal seedlings, dead seeds, and seedlings with open cotyledonary leaves. Electrophoretic analysis of isoenzymes catalase, esterase, superoxide dismutase and peroxidase was also performed. With the evolution of development the coffee seeds presents increases on physiological quality, and at its beginning the seeds show improvements on quality with the reduction of solar radiation.

Drying kinetics of jatropha seeds

Given the necessity of developing jatropha cultivation equipment, this work adjusted different mathematical models to experimental data obtained from the drying of jatropha seeds submitted to different drying conditions and selected the best model to describe the drying process. The experiment was carried out at the Federal Institute of Goiás - Rio Verde Campus. Seeds with initial moisture content of approximately 0.50 (kg water/kg dry matter) were dried in a forced air-ventilated oven, at temperatures of 45, 60, 75, 90 and 105°C to moisture content of 0.10 ± 0.005 (kg water/kg dry matter). The experimental data were adjusted to 11 mathematical models to represent the drying process of agricultural products. The models were compared using the coefficient of determination, chi-square test, relative mean error, estimated mean error and residual distribution. It was found that the increase in the air temperature caused a reduction in the drying time of seeds. The models Midilli and Two Terms were suitable to represent the drying process of Jatropha seeds and between them the use of the Midili model is recommended due to its greater simplicity.

Effect of acetic acid on rice seeds coated with rice husk ash

Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência), five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed) and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM), with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

Kinetics of solute leachate from imbibing Caesalpinia echinata Lam. (Brazilwood) seeds

The electrical conductivity of leachates from imbibing seeds has been used as a vigor test for several species. The adaptation of this methodology to different species requires knowledge on the leaching kinetics of electrolytes. For Brazilwood seeds, the classic method was not satisfactory and rapid tests are essential because they have low storage capacity at room temperature. Leaching kinetics during seed imbibition is a function of physiological quality, presence or absence of seed coat, imbibing temperature and the initial moisture content of seed. In this study, the electrolyte leaching rate of six different categories of seeds, from two regions, was evaluated in seeds with and without seed coat and incubated with different moisture contents and at different temperatures. The results showed that the electrolyte leaching rate in Brazilwood seeds is independent of the physiological quality, the presence or absence of seed coat and imbibition temperature, but these factors changed the total amount of electrolytes leached. The leaching rate increased in the first few minutes of imbibition, suggesting that the adjustment of the methodology must consider the reduction in imbibition time, reduction in temperature, use of a controlled and slower pre-imbibition, and replacement of the imbibition solution after the first few minutes.

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index), electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

Initial performance of corn in response to treatment of seeds with humic acids isolated from bokashi

ABSTRACT The humified organic matter presents bioactivity similar to the auxinic effect. As bokashi is produced by a special process of humification, information is needed about the bioactive potential of its humic acids. The objective of this work was studying the initial performance of corn-indicator plants in response to the application of different concentrations of humic acids isolated from bokashi. The corn seeds were treated for 16 hours with solutions containing 0, 10, 20, 30, 40 and 80 mmol L-1 of C in the form of humic acids. Then, the seeds were planted in pots of 1 dm3 containing corrected and fertilized soil, in greenhouse. Growth characteristics of shoot and root systems were evaluated. The results showed that the humic acids extracted from bokashi had positive effects on the initial performance of corn.

Dead man: um encontro com o passado desconhecido

O filme de Jim Jarmusch, Dead man, aparentemente um western, excede as tradicionais fronteiras do gênero, abordando ambivalência, papéis obscuros em um ambiente situado entre os tempos da fundação da nação americana e o sucesso da civilização. Isso mostra um mundo em transformação, onde a mudança está acontecendo sem ser administrada. O filme é uma provocação pela aderência aos tradicionais filmes de western. Mas, olhando mais de perto, esse mundo oferece um surpreendente insight em relação à dinâmica envolvida nos processos de mudança que também se seguem às fusões ou aquisições no mundo contemporâneo dos negócios. O charme de usar o filme como uma metáfora é ao menos ambíguo. A interpretação realizada com a ajuda de Lyotard e Baudrillard revela uma dinâmica duplamente crítica, na qual o novo proprietário bem sucedido, após a aquisição, não é necessariamente quem controla o jogo. Além disso, o uso de um filme que está fora do mainstream oferece um argumento, do âmago de um tópico central de management, que não faz parte do mainstream.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis

INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

Dispersal of seeds of Hymenaea courbaril (Fabaceae) in a logged rain forest in the Peruvian Amazonian

Seed dispersal of Hymenaea courbaril was studied by following the fate of 585 seeds embedded with small magnets and set in displays in and near a logged strip in rain forest in the Peruvian Amazonian. Mammals took fruits from all displays, which were located in the forest, edge, and cleared strip. Overall removal rates were low - a median of 8.1 fruits / month from displays maintained with 8-10 fruits - but were higher in August than in earlier months. Most fruits were dropped near the display or had their seeds eaten, but > 13% were successfully dispersed. Most of the dispersed seeds were buried, which increases probability of germination. Maximum dispersal distance of live seeds was 12.1 m (median 3.1 m), but other magnets were transported up to 34 m, indicating seeds were dispersed further, but then eaten. Acouchies (most likely Myoprocta pratti) and agoutis (Dasyprocta fuliginosa) were apparently the main dispersal agents. Dispersal of seeds from the forest into the logged strip was rare, suggesting that although rodents disperse H. courbaril, they cannot be relied on for the reseeding this and similar species in recent clearings.

Preconditioning of Physalis angulata L. to maintain the viability of seeds

The important chemical and food properties conferred to P. angulata make it necessary to conduct studies in seed conservation. This study evaluated the effect of priming of P. angulata seed for varying periods and storage conditions. Lots of seeds were stored in a refrigerator and in ambient conditions for up to 24 months. Some of these seeds were primed before or after storage. The results show that there was variation in moisture content. The germination rate and germination rate index remained high in ambient conditions when primed up to 24 months.