Avaliação de hastes sulcadoras na mobilização do solo em semeadura direta do milho

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Recolhimento mecanizado do café em função do manejo do solo e da declividade do terreno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seedlings production of Tabebuia heptaphylla in different substrates and levels of irrigation, in greenhouse conditions

The objective of this research was to evaluate the growth of Tabebuia heptaphylla seedlings in distinct substrates with different amounts of urban waste compost and the relation between this growth and irrigation. A completely randomized experimental design was used, with a factorial arrangement of 15 substrates and 2 irrigation levels. The substrates were composed by the combination of different materials: urban waste, tanned cattle manure, vermiculite, soil and the commercial form Plantmax (R). For the study of the seedlings development, the following characteristics were evaluated: plant height, stem diameter at soil level, number of leaves, above ground dry matter, root system dry matter, relation between plant height and stem base diameter, Dickson quality index and relation between plant height and above ground dry matter. Evaluations of plant height, stem diameter at soil level and number of leaves were made at 75, 90, 105, 120, 135 and 150 days after sowing. According to the results, it was concluded that urban waste compost does not increase plant development. Significant differences in relation to the irrigation levels were found, with better results for the 150% irrigation level compared to 100% evapotranspiration.

Simulations under Ideal and Nonideal Conditions for Characterization of a Passive Doppler Geographical Location System Using Extension of Data Reception Network

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

Toxicity of barbatimao to Apis mellifera and Scaptotrigona postica, under laboratory conditions

Two species of plants commonly known as barbatim (a) over tildeo occur in Brazil, Stryphnodendron adstringens (Fabaceae) (true barbatim (a) over tildeo) and Dimorphandra mollis (Caesalpiniaceae) (false barbatim (a) over tildeo). These two species have a similar flowering period and are considered by beekeepers to cause bee mortality during this period. Flowers were collected from both species, dehydrated, ground and incorporated into an experimental diet for bees of two different species, Apis mellifera and Scaptotrigona postica. Both plant species were toxic to A. mellifera, reducing their median survival. D. mollis was toxic to S. postica, and Stryphnodendron adstringens reduced median survival of this bee species even when used at a concentration of 2.5%. In a choice experiment carried out with A. mellifera and the two plant species, the honey bees could choose not to feed on the diets containing the flowers, and feed on sugar and honey instead, but they did not. This shows us that the flowers of S. adstringens were not repellent to the bees. The plants were more toxic to A. mellifera than to Scaptotrigona postica, a result that can be explained by the fact that A. mellifera was introduced into Brazil whereas S. postica is a native stingless bee.

Podzolization as a deferralitization process: dynamics and chemistry of ground and surface waters in an Acrisol-Podzol sequence of the upper Amazon Basin

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

GROUND-STATE-ENERGY OF SINGULAR POTENTIALS

It is shown that for singular potentials of the form lambda/r(alpha),the asymptotic form of the wave function both at r --> infinity and r --> 0 plays an important role. Using a wave function having the correct asymptotic behavior for the potential lambda/r(4), it is, shown that it gives the exact ground-state energy for this potential when lambda --> 0, as given earlier by Harrell [Ann. Phys. (NY) 105, 379 (1977)]. For other values of the coupling parameter X, a trial basis;set of wave functions which also satisfy the correct boundary conditions at r --> infinity and r --> 0 are used to find the ground-state energy of the singular potential lambda/r(4) It is shown that the obtained eigenvalues are in excellent agreement with their exact ones for a very large range of lambda values.

Influence of sugar cane vinasse on the sorption and degradation of herbicides in soil under controlled conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Combined characterisation of GOME and TOMS total ozone measurements from space using ground-based observations from the NDSC

Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe TOMS, and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both GOME and TOMS several sources of discrepancies: (i) a SZA dependence with TOMS beyond 80° SZA; (ii) a seasonal SZA dependence with GOME beyond 70° SZA; (iii) a difference of sensitivity with GOME at high latitudes; (iv) a difference of sensitivity to low ozone values between satellite and SAOZ sensors around the southern tropics; (v) a north/south difference of TOMS with the ground-based observations; and (vi) internal inconsistencies in GOME total ozone. © 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Performance of cultivars of crisp mini-lettuce with respect to ground cover and spacing, in three planting times

The planting of lettuce in greenhouses, as well as covering beds with a polyethylene sheet, is a viable technology, promoting improvements in microclimatic conditions of the environment. In view of the little information on mini-lettuce, the aim of this work was to evaluate the performance of three cultivars of crisp minilettuce ('Green Frizzly', 'Red Frizzly no. 1' and 'Red Frizzly no. 2') with and without ground cover, under different spacings (20 × 15 cm and 20 × 20 cm), in three planting times (1: November 16, 2004; 2: December 17, 2004; and 3: January 20, 2005). The study was conducted in a greenhouse at UNESP-FCAV, Jaboticabal-SP. The experiments were carried out using a randomized block design, following a 3 × 2 × 2 factorial scheme with 12 treatments and three repetitions. The characteristics evaluated were plant height (cm), head diameter (cm), fresh weight (g) and number of leaves per plant. Planting time 3 was shown to be favorable for all the characteristics analyzed. 'Red Frizzly no. 2' was found to be the most suited to planting time 1, and for planting times 2 and 3, this cultivar did not differ from 'Red Frizzly no. 1'. The factor ground cover was not found to affect the characteristics evaluated, and therefore, cultivation without ground cover is recommended. The spacing 20 × 15 cm was shown to be favorable, resulting in cultivation with the highest populations, thereby increasing productivity. Based on the results obtained and for the conditions in which the experiment was conducted, it can be concluded that: planting time 3 (January 20, 2005) was the most favorable; the cultivars 'Red Frizzly no. 2' and 'Red Frizzly no. 1' are adapted to all the planting times; and cultivation without ground cover using a spacing of 20 × 15 cm was the most suitable.

Assessment of modernized GPS L5 SNR for ground-based multipath reflectometry applications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ground reaction forces during level ground walking with body weight unloading

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