Doses de zinco e nitrogênio na produtividade e qualidade de grãos de ervilha

Peas present a potential to be cultivated in the winter, in Brazil, and also a great importance, especially in human feeding, due to its high protein content. However, its yield is still low and there are just a few studies aiming at improving pea grains quality and yield. This study aimed at evaluating the nitrogen and zinc fertilization effect on the pea grains (Utrillo cultivar) chemical quality and yield. The experiment was carried out in a dystrophic clayey Latosol-Haplustox, in Selvíria, Mato Grosso do Sul State, Brazil, in 2005. A randomized blocks design was used, in a 4×4 factorial scheme, totaling 16 treatments and 3 replications, including four nitrogen doses (0 kg ha-1, 60 kg ha-1, 120 kg ha-1, and 240 kg ha-1), as urea, via ground, at 30 days after sowing (DAS), and four zinc doses (0 kg ha-1, 1,5 kg ha-1, 3 kg ha-1, and 6 kg ha-1), as zinc sulphate, via leaf, at 45 DAS. The combination of zinc and nitrogen doses improved the grains chemical quality. Zinc had no effect on grain yield, however, high nitrogen doses negatively affected yield.

Ventricular systolic reserve in asymptomatic children previously treated with low doses of anthracyclines: A longitudinal, prospective exercise echocardiography study

Background: The time course of mild cardiotoxicity induced by anthracycline remains unknown. The aim of this study was to evaluate the long-term evolution of decreased myocardial reserve in children previously treated with a cumulative dose of anthracycline up to 100mg/m 2. Patients and Methods: Twenty-seven asymptomatic cancer survival patients (25 with lymphoblastic leukemia), in continuous remission and off treatment for >12 months with no alterations in conventional echocardiograms were evaluated by exercise echocardiography at 37±15.4 months (T1) and 101±24 months (T2) after finishing treatment (ADRIA group). This group was compared with 25 healthy individuals (control group) similar to the ADRIA group with respect to age and body surface area (BSA). All individuals underwent treadmill exercise testing according to Bruce protocol. Echocardiograms were performed before and immediately after exercise. Results: The groups were similar regarding cardiac structure and left ventricular (LV) systolic function at rest at T1 and T2. The growth of LV posterior wall thickness related to BSA was lower in the ADRIA group at T2. Post exercise, smaller LV ejection indexes and attenuated changes in the afterload in ADRIA group were observed at T1 and T2. Conclusion: The decreased systolic reserve induced by a low dose of anthracycline in asymptomatic children and adolescents remains unaffected over a 5-year period, suggesting that positive outcomes in chronic cardiotoxicity would be expected in patients with mild impairment after anthracycline treatment. © 2011 Wiley Periodicals, Inc.

Propagação in vitro de Cattleya trianaei (Linden & Reichenbach fil.) (Orchidaceae) em meios de culturas e com doses de fertilizante comercial

The use of culture media produced with commercial fertilizers can represent a simple and low cost alternative for commercial orchid propagation. The aim of this study was to evaluate the in vitro growth of plantlets of Cattleya trianaei in culture medium MS reduced and and formulated with Peters® NPK 10-30-20 in different doses. 90 day-old plantlets with two leaflets were submitted to five treatments (T1 - reduced MS; T2 - Peters® 1 g L -1; T3 - Peters® 2 g L-1; T4 - Peters® 3 g L -1 and T5 - Peters® 5 g L-1) arranged in a completely randomized design with five replicates with 25 plantlets for each treatment and incubated during 180 days, with subcultures at each 60 days, when the number of roots, root length, number of leaves, shoot length and shoot fresh matter were evaluated. The simplified culture medium with fertilizer Peters® 3 g L -1 presented results statistically different as for the number of roots, number of leaves, shoot length and shoot fresh matter and it can be recommended for in vitro growth of this ornamental orchid.

Doses de potássio em cobertura na cultura da abóbora

Although there are recommendations for the fertilization of commercial squash crops, studies which connect the effect of topdressing potassium fertilization and yield are still rare. Thus, this study aimed at evaluating topdressing potassium doses on squash (Mirian hybrid) yield, in an experimental farm of the Universidade Estadual Paulista Júlio de Mesquita Filho, in São Manuel, São Paulo State, Brazil. The experimental design was randomized blocks, with five treatments (0.0 kg ha-1, 50.0 kg ha-1, 100.0 kg ha-1, 200.0 kg ha-1 and 400.0 kg ha-1 of K2O) and six replications. Plant growth parameters, yield and fruit quality were evaluated. After harvesting, plant (leaves + stem) and soil macronutrients were submitted to chemical analysis and data to variance and regression analysis. It was concluded that the highest yield resulted from the topdressing dose of 199.0 kg ha-1 of K2O. A reduction in calcium and magnesium contents in the plant canopy and a higher K+ content in the soil were observed for increasing K2O levels.

Doses e épocas de aplicação de nitrogênio em cobertura na qualidade fisiológica de sementes de milho doce

The amount and timing of nitrogen application can favor seed quality, such as increasing protein content, which is an important constituent for embryo development. The objective of this study was to evaluate the physiological quality of sweet corn seeds collected from plants cultivated with different dosages and timings of nitrogen top-dressing applications. Seeds of the BR 400 variety (Super Sweet) were used obtained from plants submitted to dosages of 0, 40, 80 and 120kg ha -1 of N in two top-dressing applications (vegetative and reproductive stages). The weight of 100 grains, germination, first count of germination test, dry weight of normal seedlings from the germination test, seedling growth, cold test, accelerated aging, tetrazolium vigor and electric conductivity and emergency speed rate were determined. Data was submitted to an analysis of variance using the F-test at the 5% level and second degree regression analysis. The dosage and time of application of nitrogen top-dressing did not affect seed weight or the germination of sweet corn seeds. An increase of the N top-dressing dosage, applied in the vegetative stage reduced the length of the aerial part, the root and the whole seedling.

Fontes e doses de giberelina no desempenho de arroz anão em biotestes

Mutant of dwarf rice (Oryza sativa L.) were treated with three different concentrations of gibberellic acid originated from two sources (Gibberellin and Pro-Gibb) and submitted to the determination of bigger height, in relation to the soil leveI. Mensurations were realized in each seven days at greenhouse conditions under mean temperature of 25°C. lt was concluded that concentrations of 10 mg L-1 of gibberellin originated from Pro-Gibb or Gibberellin was enough to promote a differentiated performance of the test plant. For the study of leaf anatomy Pro-Gibb presented, under all tested concentration, increase of mesophyll thickness in relation to Gibberellin. In this analysis, source and interaction between source and concentration applied promoted significant variations between the mean data.

Adubação de cobertura na batata-doce com doses combinadas de nitrogênio e potássio

Balanced fertilizations with N and K often increase the performance of crops, however, when there is absence of one of these nutrients in poor soils, can reduce crop response to fertilization with the other. The objective of this work was to evaluate the productivity of sweet-potato, the amount of sweetpotato without quality, and leaf nutrients analysis, of sweet-potato crop fertilized with N and K. The trial was conducted in farming for commercial production, in Presidente Prudente, São Paulo State, during February-June 2007, in a dystrophic Ultisol of medium texture. The experimental design was a randomized complete block design, with four replications, on factorial 4 x 4: levels of 0, 30, 60 and 120 kg N ha-1 (urea source) combined with levels of 0, 30, 60 and 120 kg K2O ha-1 (KCl source), applied to 39 days after planting of the crop. The sweet-potato is responsive to topdressing application with nitrogen and potassium, however, the greatest increases in productivity occur when doses of N and K are combined. Fertilization with N and K not increase the amount of sweet-potato without quality marketing. The highest increase in productivity of sweet-potato is reached with topdressing combined with 100 kg N ha-1 plus 120 kg K2O ha-1.

Efeito de cultivares de repolho e doses de extrato aquoso de nim na alimentação e biologia de Plutella xylostella (linnaeus) (lepidoptera: Plutellidae)

The isolated and associated effects of cabbage cultivars Ruby Ball and Chato de Quintal and aqueous extract of seeds of fruits of neem (Azadirachta indica A. Juss.) were evaluated in the concentrations of 5 and 10% on Plutella xylostella (L.) attractiveness, feeding and development. In free-choice no-preference for feeding test, leaf discs of each treatment were placed in Petri dishes where three caterpillars/treatment were released while in no-choice test two caterpillars were placed in Petri dishes with one leaf disc in each dish. In the biology test, neonate larvae were transferred to Petri dishes in the proportion of one per dish, whereas the biological parameters were evaluated: larvae mortality after 1, 3 and 5 days; pupae mortality; total mortality; six day-old larvae weight; 24 hour-old pupae; and adult longevity. Cultivar Ruby Ball showed lower attractiveness to the caterpillars in free-choice test. Neem extract in both concentrations was repellent to the caterpillars in free-choice test. There were no differences in the dry mass consumed by the caterpillars in free-choice and no-choice tests. There were no differences in larval, pupal and total mortality between the cultivars. Both doses of neem extract were equally efficient in the mortality of the diamondback moth. There were no differences in caterpillars and pupae weight and in the longevity of the adults of P. xyostella between the cultivars.

Análise química da folha d de abacaxizeiro cv. smooth cayenne antes e após a indução floral em função de doses e parcelamentos de nitrogênio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cellular responses in the Malpighian tubules of Scaptotrigona postica (Latreille, 1807) exposed to low doses of fipronil and boric acid

Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas. © 2013 Elsevier Ltd.

Effects of low doses of polyunsaturated fatty acids on the attention deficit/Hyperactivity disorder of children: A systematic review

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

Effects of sublethal doses of imidacloprid in malpighian tubules of africanized Apis mellifera (Hymenoptera, Apidae)

In Brazil, imidacloprid is a widely used insecticide on agriculture and can harm bees, which are important pollinators. The active ingredient imidacloprid has action on the nervous system of the insects. However, little has been studied about the actions of the insecticide on nontarget organs of insects, such as the Malpighian tubules that make up the excretory and osmoregulatory system. Hence, in this study, we evaluated the effects of chronic exposure to sublethal doses of imidacloprid in Malpighian tubules of Africanized Apis mellifera. In the tubules of treated bees, we found an increase in the number of cells with picnotic nuclei, the lost of part of the cell into the lumen, and a homogenization of coloring cytoplasm. Furthermore, we observed the presence of cytoplasmic vacuolization. We confirmed the increased occurrence of picnotic nuclei by using the Feulgan reaction, which showed the chromatin compaction was more intense in the tubules of bees exposed to the insecticide. We observed an intensification of the staining of the nucleus with Xylidine Ponceau, further verifying the cytoplasmic negative regions that may indicate autophagic activity. Additionally, immunocytochemistry experiments showed TUNEL positive nuclei in exposed bees, implicating increased cell apoptosis after chronic imidacloprid exposure. In conclusion, our results indicate that very low concentrations of imidacloprid lead to cytotoxic activity in the Malpighian tubules of exposed bees at all tested times for exposure and imply that this insecticide can alter honey bee physiology. © 2013 Wiley Periodicals, Inc.

Crescimento inicial e nutrição de cedro (Cedrela fissilis Vell.) em função de doses de nitrogênio

We aimed to evaluate the effects of nitrogen rates in early growth, SPAD index, content and accumulation of nutrients in cedar seedlings. The experiment was carried out in a plastic greenhouse and the seedlings were grown in plastic pots filled with 20 dm-3of Rhodic Hapludox, arranged inrandomized blocks with four replications. Rates of 0, 40, 80, 120 and 160 mg dm-3N were tested. Fertilization up to 160 mg dm-3N promoted increases in SPAD index and early growth of plants, beyond greater absorption of N,P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. Overall, lower N rates limited growth but not the absorption of nutrients by cedar plants. In leaves, the only nutrien taffected was the B which their content was reduced with increasing of N rate. Increased of nitrogen fertilization changed the Cu distributionin plants, since increased Cu content in roots and reduced their content in stem. Higher N rates promoted higher accumulation of all nutrients due to the increase of dry matter. Nitrogen fertilization changed the dynamic of nutrient absorption in cedar. With 160 mg dm-3N, the amount absorbed followed the order: N>S>Ca>K>Mg>P>Fe>Mn>B> Zn> Cu.

Acúmulo de nutrientes no colmo de cana-de-açúcar em função de fontes e doses de manganês

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of reduced fungicide doses on control of soybean Asian rust and bean yield

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)