Aspectos técnicos e econômicos da poda e do controle químico de Brevipalpus phoenicis no manejo da leprose dos citros

The objective of this study was to evaluate different citrus leprosis management tactics during seven seasons, based in pruning and acaricide applications, considering technical and economic aspects of each tactic. The trial was conducted from October 2003 to August 2010 in an orange plantation of Pera cv. located in the municipality of Reginópolis-SP, Brazil. The plants of citrus used were12 years old and grafted onto Cleopatra tangerine. The experimental design used was randomized blocks, in a factorial scheme, made up of factors type of pruning (A), with six levels: (1) drastic pruning, (2) intermediate pruning without leprosis lesions, (3) intermediate pruning with leprosis lesions (4) light pruning, (5) without pruning and (6) replant; acaricide applications factor (B), with three levels: (1) without acaricides applications, (2) with lime sulfur applications and (3) spirodiclofen or cyhexatin applied in rotation; pruning factor to remove leprosis symptomatic branches (C), with two levels: (1) with pruning for removal, (2) without removal pruning. The combination of factors, with respective levels (6 x 3 x 2), resulted in 36 treatments that were repeated four times, with each parcel being made up of three plants in a row. After seven years, it was observed that the types of the pruning and remove of leprosis symptomatic branches used as single management tactic, is not sufficient to leprosis control. Therefore, the results demonstrated that for leprosis management, it is essential the association between tactics, especially the control mite vector. For ensuring the citrus production economically, the use of acaricides highly efficient is essential in B. phoenicis control. The recommendation of the type of pruning should be in function of the leprosis incidence and severity in the orchard. In orchards with low leprosis incidence and severity the light pruning is more appropriate, because it is efficient and ensures greater financial balance. However, in orchards with high leprosis incidence and severity it is indicated the severe pruning for reducing or eliminating inoculum source. Between the severe prunings, the intermediate pruning with leprosis lesions is the most relevant, because the financial return will be faster. Replant is indicated only for young orchards, because does not imply in changes onto cultural practices.

Avaliação de microrganismos antagônicos, Saccharomyces cerevisiae e Bacillus subtilis para o controle de Penicillium Digitatum

Citrus fruits are affected by diverse diseases, mainly the fungal infections, which affect productivity and quality, especially when it targets the market of fresh fruit. Among the fungal diseases that occur in postharvest, there is the green mold caused by Penicillium digitatum. The control measures are based mainly in the treatment of fruits with different combinations of fungicides in packing-house. Due to restrictions on the presence of residues of fungicides in citrus fruits and the increasing development of resistant strains of pathogens to the fungicide used, it is necessary to search for control alternatives such as biological control. Therefore, this study aimed to: (i) verify the antagonistic effect of biological control agents (BCA), being 13 isolates of Bacillus subtilis and 06 isolates of Saccharomyces cerevisiae against P. digitatum, (ii) study in vitro interactions between pathogen and BCA (iii) determine the effect of integration of antagonists with sodium bicarbonate and carnauba wax in the control of green mold. The results showed that the majority of the isolates, and all yeast isolates inhibited the mycelial growth of the phytopathogen. Only one isolate of B. subtilis (ACB-84) was able to inhibit the germination of P. digitatum (72% of inhibition), whereas ACB-K1 and ACB-CR1 (S. cerevisiae) were the most effective with inhibition from 78 and 85.7% respectively. The addition of sucrose (0.5%) favored the inhibition of conidia germination by the yeast isolates. The results from the in vivo control showed the viability of S. cerevisiae ACB-K1 and ACB-CR1 to control P. digitatum in 'Tahiti' lime fruits and orange 'Hamlin' fruits, respectively. The combination of sodium bicarbonate and biocontrol agents did not result in improvements in the curative control of the green mold. Carnauba wax (18% of TSS) favored the antagonistic activity of S. cerevisiae, and this effect depended on the variety of fruits in the study and of the yeast isolate used for the biocontrol.

Deposition of Al2O3 by resistive evaporation and thermal oxidation of Al to be applied as a transparent FET insulating layer

Alumina thin films have been obtained by resistive evaporation of Al layer, followed by thermal oxidation by means of annealing in appropriate atmosphere (air or O2-rich), with variation of annealing time and temperature. Optical and structural properties of the investigated films reveal that the temperature of 550 °C is responsible for reasonable oxidation, which is accelerated up to 8 times for O2-rich atmosphere. Results of surface electrical resistivity and Raman spectroscopy are in good agreement with these findings. Surprisingly, X-ray and Raman data suggest also the crystallization of Si nuclei at glass substrate-alumina interface, which would come from the soda-lime glass used as substrate. © 2013 Elsevier Ltd and Techna Group S.r.l.

Eficiência de escórias de siderurgia na cultura do feijoeiro em sistema de semeadura direta

In the no till system, soil acidity correction practice is restricted to limestone use and there is little information regarding slag. The study aimed to evaluate the amendments in soil chemical properties, yield and bean nutrient uptake according to the application forms of slags, compared to limestone, in the implantation of no till system. The experiment was conducted in the field at College of Agricultural Sciences, Botucatu (SP) from December 2010 to May2011. The treatments consisted of two application ways of seven soil acidity correctives: steel slag, blast furnace slag, ladle furnace slag, stainless steel slag (agrosilício), wollastonite, lime and calcined dolomite lime, plus one control without corrective application. Each material dose was calculated to raise the base saturation to 70%. Soil acidity was neutralized down to 20cm with limestones, whereas for wollastonite and ladle furnace slag those effects occurred down to 10cm, for steel slag, blast furnace slag and agrosilício the corrective effect was restricted to the first 5cm. The bean yield increased by application of correctives in soil acidity, without differences between the application ways.

Yield and mineral nutrition of soybean, maize, and congo signal grass as affected by limestone and slag

The objective of this work was to evaluate the efficiency of superficial applicationof limestone and slag, and their effects on soil chemical attributes and on yield and mineral nutrition of soybean, maize, and Congo signal grass (Urochloa ruziziensis). The experiment was carried out in a Rhodic Hapludox under no tillage system. The treatments consisted of the use of limestone or slag (silicates of calcium and magnesium) to correct soilacidity, and of a control treatment without the use of soil correctives. Rates were calculated in order to raise soil base saturation up to 70%. Soybean was sown in November 2006and maize in December 2007. Congo signal grass was sown right after the harvests of soybean and maize, and it was cropped during the offseasons. Soil chemical attributes were evaluated at 6, 12, and 18 months after the application of the corrective materials. Slag isan efficient source for soil acidity correction, being able to raise the exchangeable base levels in the soil profile faster than lime. Both limestone and slag increase dry matter yield of Congo signal grass, and grain yield of soybean and maize. Slag is more effective in improving maize grain yield.

Lodos de esgoto, escória de aciaria e lama cal na cultura da soja sob sistema plantio direto em latossolo vermelho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aplicação de escória de aciaria e calcário no solo e desenvolvimento do primeiro ciclo da grama bermuda

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interação de doses de calcário e zinco na mamoneira

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Espécies vegetais de cobertura e resíduos industriais e urbanos na cultura da soja em sistema de semeadura direta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Disponibilidade de fósforo em função da aplicação de calcário e silicatos em solos oxídicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de eficiência relativa para a reatividade em silicatos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Persistência de palhada de plantas de cobertura em função de doses de silício e resposta do feijoeiro em sucessão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito residual da aplicação superficial de calcário e gesso nas culturas de soja, aveia-preta e sorgo granífero

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

Alterações físicas e químicas do solo em função do sistema de produção e da aplicação superficial de silicato e calcário

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

Adubação fosfatada e lodo de esgoto compostado na nutrição da mamoneira de porte baixo, cultivada sob calagem e silicatagem

Pós-graduação em Agronomia (Agricultura) - FCA