Efeito do alumínio sobre o crescimento de duas espécies florestais

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

Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

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

Polyamines in tomato plants grown during an incidence of tospovirus exposure

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

Gas sensor applications of zinc oxide thin film grown by the polymeric precursor method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Heating value of eucalypt wood grown on SRC for energy production

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

RESPONSE OF CORN GROWN IN TILLAGE SYSTEM FOR THE APPLICATION OF NITROGEN DOSES IN A SEQUENCE OF PLANT COVER

The use of cover crops can produce large amounts of biomass, improving the cycling of nutrients, particularly nitrogen, promoting productivity gains and cost savings. Given this, the objective was to evaluate the use of N rates associated to cover crops grown in pre-harvest nutritional status, nitrogen accumulation and corn yield in both years. The experiment was conducted in an Oxisol with maize, no-tillage system. The experimental design was a randomized block, split plot with four replications. The main treatments were: six cropping systems (sun hemp, jack bean, lablab, millet, and velvet bean fallow) in secondary treatments: four doses of nitrogen (0, 60, 120 and 180 kg ha(-1) N). Corn yield was not affected by the type of coverage for pre-season, regardless of the nitrogen applied in the soil. Still, the use of nitrogen fertilizer in the soil promotes gains in grain yield in the first year of cultivation, regardless of the type of coverage in pre-season. In the first year (2006/2007) the species of coverage produced more biomass were velvet bean, jack bean, sun hemp and lablab, while in the second year (2007/08) were the sun hemp, millet, lablab, jack bean and velvet bean, respectively.

Gas sensor properties of zno nanorods grown by chemical bath deposition

The present work shows a study about the growing of ZnO nanorods by chemical bath deposition (CBD) and its application as gas sensor. It was prepared ZnO nanorods and Au decorated ZnO nanorods and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas sensing response measurements. The results obtained by XRD show the growth of ZnO phase. It was possible to observe the formation of uniform dense well-aligned ZnO nanorods. The results obtained also revealed that Ag nanoparticles have decorated the surface of ZnO nanorods successfully. Au nanoparticles with diameter of a few nanometers were distributed over the ZnO surface nanorods. The gas sensing response measurements showed a behavior of n type semiconductor. Furthermore, the Au-functionalized ZnO nanorods gas sensors showed a considerably enhanced response at 250 and 300 °C.

Mutagenic potential of lettuce grown from irradiated seeds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Two-spotted spider mite and its natural enemies on strawberry grown as protected and unprotected crops in Norway and Brazil

Cultivation of strawberry in plastic tunnels has increased considerably in Norway and in southeastern Brazil, mainly in an attempt to protect the crop from unsuitable climatic factors and some diseases as well as to allow growers to expand the traditional production season. It has been hypothesized that cultivation under tunnels could increase the incidence of one of its major pests in many countries where strawberry is cultivated, including Norway and Brazil, the two spotted spider mite, Tetranychus urticae. The objective of this study was to evaluate the effect of the use of tunnels on the incidence of T. urticae and on its natural enemies on strawberry in two ecologically contrasting regions, Norway (temperate) and southeastern Brazil (subtropical). In both countries, peak densities of T. urticae in tunnels and in the open fields were lower than economic thresholds reported in the literature. Factors determining that systematically seem to be the prevailing relatively low temperature in Norway and high relative humidity in both countries. The levels of occurrence in Norway and Brazil in 2010 were so low that regardless of any potential effect of the use of tunnel, no major differences were observed between the two cropping systems in relation to T. urticae densities. In 2009 in Norway and in 2011 in Brazil, increase in T. urticae population seemed to have been restrained mainly by rainfall in the open field and by predatory mites in the tunnels. Phytoseiids were the most numerous predatory mite group of natural occurrence on strawberry, and the prevalence was higher in Brazil, where the most abundant species on strawberry leaves were Neoseiulus anonymus and Phytoseiulus macropilis. In Norway, the most abundant naturally occurring phytoseiids on strawberry leaves were Typhlodromus (Anthoseius) rhenanus and Typhlodromus (Typhlodromus) pyri. Predatory mites were very rare in the litter samples collected in Norway. Infection rate of the pest by the fungus Neozygites floridana (Neozygitaceae) was low. The results of this work suggest that in Norway the use of tunnels might not affect the population densities of T. urticae on strawberry in years of lower temperatures. When temperature is not a limiting factor for the development of T. urticae in that country (apparently always the case in southern Brazil), strawberry cultivation in the tunnels may allow T. urticae to reach higher population levels than in open fields (because of the provided protection from the direct impact of rainfall), but natural enemies may prevent higher levels from being reached.

Nutritional status of the cauliflower cultivar ‘verona’ grown with omission of out added macronutrients

Knowledge of plant nutritional status allows an understanding of the physiological responses of plants to crop fertilization. A hydroponic experiment evaluated the symptoms of macronutrient deficiency in cauliflower 'Verona'and determined: a) the macronutrient contents of foliar tissues when visual symptoms were observed, b) macronutrients content of foliar and inflorescence tissues at harvest. The effect of nutrient deficiency on inflorescence mass was also evaluated. Nitrogen deficiency caused chlorosis followed by purple color in the old leaves, while P deficiency caused only chlorosis in old leaves. Chlorosis at the edge of old leaves progressing to the center of the leaves was observed with the omission of K, and after was observed necrosis in the chlorotic areas. Ca deficiency caused tip burn in new leaves, while Mg deficiency caused internerval chlorosis in old leaves. The omission of eachmacronutrient reduced inflorescence dry matter. This deleterious effect was larger for N, P, and K deficiencies, reducing inflorescence dry matter by 87, 49, and 42%, respectively. When the nutrient solutions without N, P, K, Ca, or Mg were supplied to cauliflower plants, the macronutrient contents at harvest were 8.8, 0.6, 3.5, 13.0, and 0.8 g kg(-1) in the foliar tissues and 27.3, 2.2, 21.6, 1.1, and 0.7 g kg(-1) in the inflorescence tissues, respectively.