Efeitos da idade dos frutos, método e condição de secagem sobre a qualidade de sementes de quiabeiro. II. Cultivar Amarelinho

Fruits of okra (Abelmoschus esculentus (L.) Moench.) cv. Amarelinho were harvested at three times: 35, 45 and 55 days after anthesis. Half part of the fruits of each harvest time was shelled and the seeds were dried in natural environment of laboratory or in dry chamber. The other half was dried unshelled in the same two conditions. Water contents of seeds were evaluated at harvest time and before the germination test, that was carried out when the seeds were in hygroscopic equilibrium with the two environments. The physiological quality of seeds was affected by the interaction effects of fruit age, drying method and drying condition. The highest values for percentage of germination were obtained from seeds taken from fruits 55 days old (up to 92%) and the hard seeds percentage was not affected by drying method and drying condition. The seeds from fruits of 35 and 45 days old had the germination percentage increased when dried inside the fruit in natural environment.

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.

Efeito da temperatura na germina̧ão de sementes de Sebastiania commersoniana (Baillon) Smith & Downs separadas pela colora̧ão do tegumento

Sebastiania commersoniana (Euphorbiaceae) is a tree species of riparian forests in Brazil. Seeds of this species released from mature fruits have heteromorphy in coat colour: dark (dark-brown to black), striated (dark with light-grey stria) and clear (light-grey to whitish). In this work two experiments were carried out in order to study the effect of temperature on seed germination in interaction with coat colour. Germination final percentage and speed index were evaluated. In the first experiment seeds of the three colours were submitted to constant (30°C) and alternating (20-35°C) temperatures. For all the seed colours, best results were obtained at alternating temperature. Physiological quality of striated seeds was greater than those clear seeds and dark seeds were intermediate. In the second experiment striated and clear seeds were submitted to three amplitudes of alternating temperature: 5°C (20-25°C and 25-30°C), 10°C (20-30°C and 25-35°C) and 15°C (20-35°C). Both germination percentage and speed were higher in striated seeds and for the two seed colours, best results were obtained at 20-30°C and 20-35°C. These temperatures are recommended for the germination test.

Qualidade fisiológica de sementes de Sebastiania commersoniana (Baill.) Smith & Downs (branquilho - Euphorbiaceae) durante o armazenamento

This paper aims to evaluate the physiological quality of Sebastiania commersoniana seeds stored in cloth bag, plastic bag and glass container and kept in two conditions: laboratory workbench and cold chamber (4 ± 2°C e 80% relative humidity - RH) for 531 days. Periodically, samples were taken in order to determine the moisture content and to perform germination tests. The experimental design was completely randomized, in factorial scheme of 3 × 2 (wrappings × conditions), for each period of storage evaluated (0, 158, 271, 389 and 531 days of storage). Supplementary, a polynomial regression was adjusted in order to describe the physiological quality of the seeds for the different conditions during the experimental period. The results lead to the following considerations: a) storage under variable temperature and air humidity (laboratory workbench) can be used for periods of over five and a half months, with the seeds stored in cloth bag, plastic bag or glass container; b) the physiological quality of the seeds was not hardly altered when stored in cold chamber in cloth bag, plastic bag and glass container for over 18 months.

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.

Testes de vigor para avaliação da qualidade fisiológica de sementesde Sebastiania commersoniana (Baill.) Smith & Downs.

The objective of this work was to evaluate the efficiency of different vigor tests to assess S. commersoniana seeds physiological quality during storage. Therefore, seeds were stored in cloth bags, plastic bags and glass containers for 531 days, both at room temperature and in a cold chamber. Periodically samples were taken and the following tests were conducted: standard germination, germination speed index, first count after germination, seedlings fresh and dry matter, electrical conductivity (imbibitions for 2 and 24 hours) and accelerated aging, in order to monitoring the seeds physiologic quality. Data were submitted to polynomial regression analysis, for each of the combination of packaging/storage condition. The results obtained led to the following considerations: a) the speed germination index and the accelerated aging test permitted a good evaluation of the seed-lots quality; b) the first count of germination did not allow any prediction about seed lots vigor; c) seedling fresh and dry matter did not discriminate among seed lots; d) electrical conductivity test after 2 h imbibitions was not adequate to evaluate the seed lots vigor and e) the electric conductivity test with 24 h imbibitions was more adequate to differentiate among seed lots, but with little efficiency to discriminate among seed lots with intermediate vigor or with low quality differences.

Biometria e qualidade fisiológica de sementes de diferentes matrizes de Tabebuia chrysotricha (Mart. Ex A. DC.) Stand I.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Proteína e qualidade de sementes de feijão (Phaseolus vulgaris L.) em função da adubação nitrogenada em plantio direto

Nitrogen limitation in the common bean (Phaseolus vulgaris L.) produces reduced productivity and seeds with low protein content and physiological quality. We assessed the effects of nitrogen fertilizer side dressing on the protein content and physiological quality of the seeds of P. vulgaris L. cultivars (cv.) IPR Juriti and Pérola grown in plots (soil type = Dystrophic Red Latosol) using a no-tillage system under a thick mulch of millet residues at the Experimental Station of UNESP-Ilha Solteira campus, located in Selvíria, MS (Köppen climate type = Aw) during autumn (March/June) and winter (June/September) 2005. For each cultivar, a randomized block experimental design was used with four replicates and factorially arranged treatments equivalent to 0, 30, 60, 90 and 120 kg.ha-1 added nitrogen (as urea, containing 45% of N) applied as a side dressing during the V4-3 and V4-6 phenological stage corresponding to the 3rd and 6th completely opened trifoliolate leaf on the main stem. Supplementation with up to 120 kg.ha-1 nitrogen promoted a greater increase in crude protein at V4-3 (unsupplemented = 17.6% and 16.3%; 120 kg.ha-1 N = 24.1% and 22.3% for cv. IPR Juriti and Pérola, respectively) than at V4-6 (unsupplemented = 19.2% and 18.3%; 120 kg.ha-1 N = 21.3% and 20.3% for cv. IPR Juriti and Pérola, respectively). About 90% of the crude protein from cv. IPR Juriti was composed of soluble protein compared to 72% for the cv. Pérola. Albumins and globulins represented about 80% of the soluble protein and prolamins were lower at 0.6%. In conclusion, nitrogen fertilization up to 120 kg.ha-1 applied as a side dressing at the V4-3 phenological stage in no-tillage under a thick mulch of millet promoted a greater increase of crude protein in common bean seeds than at the V4-6 stage. The highest accumulation of soluble protein occurred at 90 kg.ha-1 applied nitrogen without having a significant influence on the physiological quality of the seeds.

Testes de envelhecimento acelerado e de condutividade elétrica em sementes de Dictyoloma vendellianum A. Juss.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sementes de feijão-caupi (Vigna unguiculata L. (Walp), tratadas com extrato de folhas de nim (Azadirachta indica A. Juss.) avaliação da germinação e da incidência de fungos

This study aimed to evaluate the effect of aqueous extract of neem on germination and fungi incidence on seeds of three cultivars (Serrinha, BR 17 and Maranhão) of cowpea. Neem leaves were dryed, crushed and prepared dilutions of 0.5; 1.0; 2.0, 4.0 g dm -3and control. The fungi incidence was evaluated by the test filter paper and germination according to the Rules for Seeds Testing (Regras para Análise de Sementes). In the three cultivars analyzed, reduction in the incidence of Aspergillus sp and Fusarium sp was observed. In relation to the influence of extracts of neem leaves on seed germination, significant effect of extract in Maranhão cultivar was observed, where all concentrations differed from the control, and propovided a considerable increase in the percentage of normal seedlings. It was concluded that the leaf extract of neem was effective in controlling Aspergillus sp, Fusarium sp , Phoma sp and Macrophomina phaseolina at different concentrations in different cultivars and seed germination was stimulated for the Maranhão cultivar.

Qualidade fisiológica de sementes de diferentes árvores matrizes de Corymbia citriodora (Hook.) K.D.Hill & L.A.S. Johnson

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

Besides increasing productivity, nitrogen fertilization may have positives effects on seed physiological quality. The objective of this study was to evaluate the effect of different forms and levels of urea in top dressing fertilization on the physiological quality of wheat seed genotypes. Seeds of three wheat genotypes (BRS 208, BRS Pardela and IWT 04008) were evaluated for four levels of nitrogen fertilization (0, 40, 80 and 120 kg.ha-1) in three forms of urea (conventional urea, urea with urease inhibitor and protected urea). The nitrogen fertilization was applied during tillering, 20 days after emergence. The seed nitrogen content, 1000 seed mass, germination and vigor (germination first count, cold test, seedling emergence in the field, dry weight of seedlings, accelerated aging and electrical conductivity) were evaluated. The IWT 04008 line and the cultivar BRS Pardela had seeds with a higher physiological quality than those of the cultivar BRS 208. The forms of urea and levels of nitrogen in topdressing did not affect seed physiological quality of the different wheat genotypes.

Perdas qualitativas na colheita mecanizada de sementes de soja

The study aimed to assess the physical and physiological characteristics of soybean seeds collected in grain tank and the outlet of the discharge tube of the harvester, depending on the year and the forward speed of the harvester. The experimental design was completely randomized in a factorial 2 x 2 x 2 tested two harvesters of different years, two displacement's speeds and two locations of sample collection, totaling eight treatments with four replications. The harvest of soybean cv. COODETEC 217, was performed with two tangential harvesters, aged three and four years, with 900 rpm rotation of the cylinder, operating at forward speeds of 4 ± 0.5 km h-1 and 7 ± 0.5 km h-1. Seed samples (approximately 3 kg) were withdrawn at the grain tank and the outlet of the discharge tube of the harvester and subjected to determinations of water content in field and laboratory. Subsequently, we evaluated purity, mechanical damage, germination and seed vigor. The younger harvester had a higher percentage of pure seed and lowest percentage of inert material. The increase in forward speed provides the higher the bands percentage and reduction of percentages of pure seed and inert material. The percentage of inert material was higher for seeds collected in the discharge pipe. The speed increase has positively influenced the emergence in sand for the harvester oldest (4 years) and negatively to the harvester youngest (3 years). At lower speeds the youngest harvester higher percentage of germination in sand.

Aspectos fisiológicos e bioquímicos de cultivares de soja submetidos a déficit hídrico induzido por peg 6000

In soybean culture water deficit is one of the most limiting factors to the maximum yield obtained. Genotypes identification with drought tolerance capacity is fundamental to solve this problem. The objective in this paper was analyze the physiological quality and physiological and biochemical responses of soybeans cultivars (MG/BR 46 Conquista, UFUS Carajás, UFUS Impacta, UFUS Riqueza and UFUS Xavante) submitted to water stress with PEG 6000 solutions in different levels of osmotic potentials (0; -0,1; -0,2; -0,3 and -0,4 MPa). Physiological quality of cultivars were evaluated by seedling length test and fresh and dry biomass. The biochemical responses were evaluated by detection of indol-acetic acid (IAA), by saccharose content and seedling water transportation. UFUS Riqueza presented the best performance in physiological quality tests, saccharose content, absorption and water absorption velocity in seedling. UFUS Xavante showed the highest IAA's concentration and the greater weight of seedling in water transportation test.

Teor de clorofila, danos oxidativos e qualidade de sementes de soja

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)