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A high number of vigor tests are currently used by seed companies to evaluate the quality of seed lots. However, some of them do not always correlate with seedling performance in the field and in addition there is the disadvantage of long time interval to obtain the results. This study aimed to evaluate the efficiency of respiratory activity as a vigor test in cotton seeds. The experiments were conducted in 2012 in the laboratory and in a greenhouse. The seed of the cultivar BRS 286 was used. From the principal seed lot, three seed lots were obtained by accelerated aging for periods of zero, 48 and 96 hours. Besides the determination of respiratory activity, seed germination, seedling emergence in sand, emergence speed index, shoot and root length, dry mass of shoots and roots and electrical conductivity tests were performed. The respiratory activity classified the seed lots into three vigor levels, and was positively correlated with shoot and root length. The assessment of respiratory activity is effective as a vigor test for cotton seed. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the performance of different thermal scarification methods to overcome Piptadenia moniliformis seeds dormancy. The thermal treatments used were: control (no treatment - T1); seed immersion in water at 80 and 100 °C for 10 (T2 and T6, respectively), 30 (T3 and T7, respectively) and 60 (T4 and T8, respectively) seconds; seed immersion in water at 80 °C until cooling to room temperature (28 °C) (T5), and seed immersion in water at 100 °C until cooling to room temperature (28 °C) (T9). The seeds were placed for germination in boxes with transparent lid, containing the blotting paper substrate, which was moistened with Nystatin solution. Later, they were placed in a Biochemical Oxygen Demand germinator, regulated at 30 °C under continuous light. The following parameters were evaluated: first germination counting; final germination; germination speed index; root and shoot length; and root and shoot dry mass. The thermal scarification using seed immersion in water at 80 °C for 10 and 30 seconds was efficient in overcoming dormancy in Piptadenia moniliformis seeds, presenting the highest germination and vigor percentage. [ABSTRACT FROM AUTHOR]

The increase in the demand for seeds of castor bean in Brazil comes unchaining a great interest in tests that make possible the differentiation of lots of superior quality. Amongst the available tests, the accelerated aging is one of the most studied and recommended one for seeds of diverse crops. We used six seed lots IAC-226, and the quality assessed by the initial water content, germination, first counting of germination, plantlets emergence and emergence speed index. The seeds were submitted to accelerated aging test, adapted to temperatures 40 and 42 °C for periods of 48 and 60 hours in a completely randomized design with four repetitions. The accelerated aging was efficient for physiological potential evaluation of castor bean seeds, IAC-226 cultivar, with a temperature of 42 °C for 60 hours, the most appropriate procedure for classifying lots into different vigor levels. [ABSTRACT FROM AUTHOR]

One of the major concerns of the scientific community over the last decade regards to climate change and its consequences for humanity. The objective of this study was to estimate the spatial variability of rainfall in the State of Espirito Santo, Brazil, based on the values of geographical coordinates and altitude of the measuring stations. The rainfall values raised for 55 climatic stations located within the state area were used, considering the monthly and annual means of the time series used. The geographic coordinates and altitude data were submitted to the multivariate statistical analysis based on the principal components for its dimensional reduction. The rainfall data and the selected component were submitted to the multivariate geostatistical analysis, which yielded satisfactory results in estimating rainfall values at non-sampled areas, increasing the spatial continuity of the phenomenon. The monthly and annual rainfall in the State of Espírito Santo presented high spatial dependence for the series studied, with less variability in the northern region, where the rainfall rates are reduced. The rainfall survey is not solely dependent on the number of rain gauge stations, but mostly on their distribution throughout the area to be sampled, whereas the ideal mapping model is the one that considers both parameters together. [ABSTRACT FROM AUTHOR]

Water and salt stress are the major abiotic stresses limiting crop productivity worldwide. The reduction of quality water supplies for irrigation purposes is forcing farmers to use saline waters. The objective of this research was to evaluate the effect of irrigation with saline water on eggplant development and mineral nutrition. The experiment was carried out in greenhouse, at the Federal Rural University of the Semiarid, Mossoró municipality, Rio Grande do Norte, Brazil. The experimental design was completely randomized, with five irrigation water salinity levels (0.5; 1.5; 2.5; 3.5 e 4.5 dS m-1) and four replications. The experimental unit was a 12 m-3 pot containing one plant. A superficial sample of an Ultisol. The saline levels were obtained by dissolving NaCl in water from UFERSA Campus supply system. 70 days after the sowing, the plants were collected and the following growth parameters were evaluated: height, stem diameter, leaf number, leaf area, leaves dry matter, shoot dry matter, specific leaf area, and leaf area ratio. Nitrogen, phosphorus and potassium content were also determined in the leaf tissue. All evaluated parameters were influenced by salinity, but the most expressive results were observed for the leaf number, leaf area, and shoot dry matter. Salinity promoted reduction in N and K leaf contents. [ABSTRACT FROM AUTHOR]

B. sulphurea is a species with ornamental potential due to its beautiful inflorescence. The objective of this work was to determine the appropriate substrate for germination and vigor tests of this species. The achenes were sown into and on the substrates sand, blotting paper, coconut fiber, Tropstrato® and vermiculite and lead to B.O.D. incubator regulated at 25°C and regimen of continuous light. The following parameters were also evaluated: germination (%), first germination count (%), germination speed index, average germination period (days) and primary root length (cm). The substrates into and on vermiculite and blotting paper provided the highest seed germination and vigor in the B. sulphurea achenes. [ABSTRACT FROM AUTHOR]

This work was developed aiming at evaluating the effect of salinity and nitrogen sources on the initial development of the sunflower. The experimental design used was completely randomized, arranged in a factorial scheme 3 x 5, with four replications. The first factor was composed by different nitrogen sources (urea, ammonium sulfate and calcium nitrate), corresponding to an N rate of 100 mg dm-3; and the second factor was composed by different salinity levels of the irrigation water (0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1). The following parameters were evaluated: plant height, leaf number, leaf area and total dry mass weight. The vegetative development of the sunflower was influenced by both the salinity of the irrigation water and nitrogen sources. Leaf number, leaf area and total dry mass weight were affected by salinity. Fertilization with ammonium sulfate favors higher development of plants. [ABSTRACT FROM AUTHOR]

The objective of this research was to determine the metabolism of corn glucose and diets containing glucose for broilers from 1 to 7 days of age by total excreta collection method. Therefore, was carried out metabolism trial using 360 male broilers in the lineage Cobb500 1-7 days old. The animals were housed in metabolic cages in a completely randomized design with five treatments and six replicates of 12 birds. The treatments consisted of the basal diet and four test diets with different levels of substitution of basal diet for corn glucose (0, 5, 10, 15 and 20%). Data were subjected to analysis of variance and regression and applied Dunnett's test at 5% probability. The glucose contained in its composition 81.39% dry matter and 3824 kcal kg-1 gross energy. Significant effects for the energy values of corn, and CAMDM CAMGE of diets containing different levels of substitution of glucose. The level of 20% of the diet by replacing glucose showed the highest energy value being 3550, 3648 kcal kg-1 DM and 95.38% for AME, AMEn and CMAEB respectively. [ABSTRACT FROM AUTHOR]

This study evaluated the behavior of spontaneous vegetation in seedbed conditions, under different soil mulches and irrigation depths. The plant residues used as soil mulches were Gliricidia (Gliricidia sepium), Pigeon pea (Cajanus cajan), Cameroon grass (Pennisetum purpureum), and Bamboo (Bambusa vulgaris "vitata"), besides seedbed without mulches. The irrigation depths were characterized as T5, T4, T3, T2 and T1, corresponding to approximately 117%, 100%, 72%, 59% and 38% of reference evapotranspiration (ETo). Samplings were made 26, 64, 92, 124 and 152 days after the disposal of the plant residues. The main species identified were Cyperus rotundus, Commelina benghalensis, Digitaria horizontalis, Panicum maximum and shoots of previous crops. Plant residues led gravimetric moist urelevels in soil layers of 0.10 and 0.20 m on average 2% over the exposed soil. After the 92nd day, the dead mulching with legumes residues showed levels of soil moisture inferior to the one observed for grass residues. All studied dead mulches were able to reduce the total number of weeds emerged, but the relative frequencies and densities were similar. Cyperus rotundus presented in all treatments relative frequency above 50% and relative density above 70%, given that the residues of legumes had higher population densities and dry mass. The irrigation depth did not influence weeds relative frequencies, densities and dry mass, with the exception of Cyperus rotundus, both in time and the different mulches with plant residue. [ABSTRACT FROM AUTHOR]

The success in weed control by using straw depends on the management time, straw quality and quantity. The objective of this research was to evaluate the suppressor effect of black-oats and millet straw cover on the incidence of weeds and on the productivity of the soybean crop. The experiment was carried out during the years 2006 and 2007, in an area from the Farm of Education, Research and Production of FCAV-UNESP, Jaboticabal Campus, in a completely randomized block design, with four replications. Treatments consisted of different types of black oats and pearl millet straw management before soybean seeding (without management, obtained by machine cut, desiccated using glyphosate desiccation and with paraquat) and different periods of straw deposition (0, 15, 30 e 60 days before soybean seeding). The weed population and the characteristics of soybean growth and production were evaluated. The deposition of black oats and pearl millet straw provided reductions in weed density and dry mass, and this effect was more effective when the deposition occurred until 15 days prior to soybean seeding. The suppressor effect of black oats straw was more pronounced than that of pearl millet straw, regardless of the drying method, although the millet had a greater dry matter production. No significant differences were found between the drying methods and the straw effectiveness. [ABSTRACT FROM AUTHOR]

This study aimed at assessing the effects of solid urban waste and liming in the initial growth of Trema micrantha (L. Ulmaceae) seedlings in tubes. To conduct the study, an experiment was installed in a greenhouse, displayed in a completely randomized design, in a factorial scheme 2x5, in samples of Red Distroferric Latossol (Oxisol) with and without liming and five proportions of urban waste compost: 0; 10; 20; 40 and 80% v/v, without complementary fertilization, with five replications. 120 days after the beginning of the experiment, the seedlings were collected to determine: shoot dry matter, root dry matter and total dry matter, as well as the relation between shoot dry matter and root dry matter. There was no significant effect of lime nor its interaction with waste compost in the parameters evaluated. Waste compost increased seedlings shoot dry matter production. Such effects varied according to the proportions of compost used. The average proportion was 54.7% of solid urban waste and 45.3% of Red Distroferric Latossol (Oxisol), which favors dry matter production of Trema micrantha (L. Ulmaceae) seedlings. [ABSTRACT FROM AUTHOR]