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.

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.

Aspectos sobre a polinizaçâo do "Dendezeiro" Elaeis guineensis Jacq. e do "Caiaué" Elaeis oleifera (H.B.K.) Cortés. (ARECACEAE).

Este trabalho tem como objetivo a identificação dos insetos visitantes e polinizadores das flores do "dendê" Elaeis guineensis Jacq., e do "caiaué" Elaeis oleifera (H.B.K) Cortés, atráves de coletas em locais e horários diferentes, quando as inflorescências masculinas das plantas encontravam-se em plena antese. Um total de 159 insetos foram observados tendo sido constatado dentre os diversos tipos de visitantes, os meliponídeos: Trigona sp. ("dendê" e "caiaué"), Apis mellifera adansonni e Partamona sp. ("dendê"). Constatou-se ainda a presença de uma quantidade razoável de insetos da família Curculionidae do gênero Elaeidobius, que voavam em torno das inflorescências, sendo evidente a sua participação na polinização das espécies estudadas. Além disso, verificou-se a presença de larvas de um coléoptero da família lycidae, junto as inflorescências das plantas.

Morfologia Polínica de Populações Amazônicas de Elaeis oleifera

Elaeis oleifera (Kunth) Cortés - Arecaceae (caiaué) apresenta características vantajosas para a hibridação com o dendê E. guineensis que variam entre populações. Com o objetivo de contribuir para a discriminação de populações amazônicas, caracterizou-se a morfologia do pólen de dez populações de caiaué (Acajatuba, Amatari, Autazes, BR-174, Careiro, Manicoré, Maués, Moura, Novo Aripuanã e Tefé). Utilizou-se o método da acetólise para eliminação do conteúdo celular e observou-se o tamanho, forma, abertura e superfície dos grãos de pólen. A população Novo Aripuanã apresentou maior tamanho médio dos grãos de pólen (49,0 μm) e as populações Amatari, BR-174 e Moura os menores (42,5 a 44,0 μm). Os grãos de pólen são elípticos ou piriformes, com abertura monocolpada e superfície microrreticulada. Observou-se, também, anormalidades morfológicas em alguns grãos. A morfologia polínica separou as populações amazônicas em três grupos e, quando associada a outras análises (isoenzimas e DNA), pode representar uma ferramenta importante na discriminação de populações.

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.

Avaliação da gramatura de cola na propriedade de flexão estática em painéis compensados de Copaifera duckei Dwayer e Eperua oleifera Ducke

A presente pesquisa teve como objetivo analisar as seguintes gramaturas de cola: 270; 330; 364 e 390 g.m-² a partir da produção de compensados fenólicos utilizando duas espécies florestais; Copaifera duckei e Eperua oleifera e avaliar a flexão estática dos painéis. A madeira foi proveniente da área de manejo florestal sustentado da Indústria de Madeira Compensada localizada em Manicoré, município do Amazonas. As lâminas foram produzidas na Gethal Amazonas S.A - Indústria de Madeira Compensada em Itacoatiara - AM com espessura de 2,2 mm. Foram produzidas a nível industrial 40 painéis, 20 por espécie no total de 8 tratamentos. O experimento foi completamente casualizado com arranjo fatorial. Foi utilizado a norma Européia EN 310: 1993. Os valores de densidade básica da espécie Copaifera duckei foi de 0,60 (g.cm-²) e 0,62 (g.cm-²) para Eperua oleifera. No ensaio de flexão estática, sentido paralelo à grã, somente a espécie Copaifera duckei apresentou diferença significativa a 5% pelo Teste de Dunnette para as propriedades de MOE e MOR. No sentido perpendicular a grã, as espécies Copaifera duckei e Eperua oleifera tanto o MOE quanto o MOR apresentaram diferenças significativas a 5% de probabilidade.

Influência da gramatura na resistência da linha de cola aos esforços de cisalhamento em painéis compensados de Copaifera duckei Dawyer e Eperua oleifera Ducke

A madeira por ser um material de origem orgânica responde de várias maneiras aos diversos produtos nela empregados, inclusive a aplicação de cola a qual depende do seu teor de umidade, tendendo a atingir um teor de umidade em equilíbrio dinâmico com a umidade relativa da atmosfera. Atualmente utilizam-se lâminas com teores de umidade entre 5 e 15% de acordo com o tipo de resina utilizada. O presente estudo avaliou o efeito de 04 gramaturas (270; 330; 364 e 390 g/m²) na produção de painéis compensados utilizando as espécies: Copaifera duckei Dawyer e Eperua oleifera Ducke. As espécies utilizadas foram retiradas da área de manejo florestal sustentável da Gethal Indústria de Madeira Compensada Ltda localizada em Manicoré-Am. As lâminas foram produzidas com espessuras de 2,2 mm. As variáveis do ciclo de prensagem foram controladas seguindo as orientações técnicas estabelecidas pelo fabricante da resina. Foi avaliada a resistência da linha de cola, com amostras da capa e do miolo em condições seca e pós-fervura. Para análise estatística foi aplicado um delineamento inteiramente casualizado com arranjo em esquema fatorial dos tratamentos. Confrontando os valores médios da tensão de ruptura e a percentagem de falha na madeira obtidos nesta pesquisa, ensaio seco e pós-fervura, com os da literatura, foi verificado que os painéis avaliados atendem aos critérios estabelecidos, podendo ser indicados para uso interior e exterior, pois de acordo com a Norma EN 314-2 (1993) o valor médio da tensão de ruptura em conjunto com a porcentagem de falha na madeira encontram-se em um padrão aceitável de comportamento.

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.

Infection by microorganisms on soybean seeds obtained from plants treated with growth regulators

This research, deals with the effects of exogenous growth regulators on infection by microorganisms on soybean (Glycine max cv. Davis) seeds. To study the influence of the chemicals, soybean plants were sprayed with gibberellic acid (GA) 100 ppm, (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm, succinic acid-2,2-dimethy1hydrazide (SADH) 4,000 ppm, indolylacetic acid (IAA) 100 ppm, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm (three applications), and Agrostemin (1g/10 ml/ 3 1). Application of growth regulators did not affect infect ion by microorganisms on soybean seeds. The prominent fungus isolated was Phomopsis sojae. Alternaria and Fusarium spp. were isolated from seeds. The presence of a bacterium on the seeds was observed. The delay in harvest and high humidity increased the number of seeds from which Phomopsis was recovered.

The resistance of seeds of cowpea (Vigna unguiculata) to the cowpea weevil (Callosobruchus maculatus)

Cowpea (Vigna unguiculata) seeds are heavily damaged during storage by the bruchid Callosobruchus maculatus. Seeds of some Nigerian varieties showed a strong resistance to this bruchid. By utilizing biochemical and entomological techniques we were able to rule out the paticipation of proteolytic enzyme (trypsin, chimotrypsin, subtilisin and papain) inhibitors, lectins, and tannins in the resistance mechanisms. Fractionation of the seed meal of a resistant variety suggests that the factor(s) responsible for the effect is (are) concentrate in the globulin fraction.

Sativa seeds against Schistosoma mansoni different stages

The schistosomicidal properties of Nigella sativaseeds were tested in vitro against Schistosoma mansoni miracidia, cercariae, and adult worms. Results indicate its strong biocidal effects against all stages of the parasite and also showed an inhibitory effect on egg-laying of adult female worms. In the present work we also studied the effects of crushed seeds on some antioxidant enzymes; which have a role in protection of adult worms against host oxidant killing; as well as some enzymes of glucose metabolism; which have a crucial role in the survival of adult worms inside their hosts. The data revealed that the used drug induce an oxidative stress against adult worms which indicated by a decrease in the activities of both antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and glutathione reductase and enzymes of glucose metabolism, hexokinase and glucose-6-phosphate dehydrogenase. Disturbing of such enzymes of adult worms using N. sativa seeds could in turn render the parasite vulnerable to damage by the host and may play a role in the antischistosomal potency of the used drug.