Liberação de micronutrientes de uma escória aplicada em um Argissolo Vermelho-Amarelo cultivado com mudas de goiabeira (Psidium guajava L.)

Os micronutrientes são importantes na nutrição das plantas, especialmente em solos tropicais com baixa concentração devido ao intemperismo. Como fonte alternativa de micronutrientes, tem-se a escória, resíduo da indústria de produção de ferro-gusa e aço. Assim, objetivou-se avaliar a escória como fonte de micronutrientes para mudas de goiabeira. O delineamento experimental foi em blocos ao acaso, com cinco repetições. As doses de escória foram aplicadas objetivando elevar em meia, uma vez, uma vez e meia, duas vezes e duas vezes e meia a saturação por bases do solo igual a 70%, correspondendo a 1,68; 3,36; 5,04; 6,72 e 8,40 g por vaso, além da testemunha sem aplicação. Após 90 dias de incubação da escória com o Argissolo Vermelho-Amarelo, cultivaram-se mudas de goiabeira (cv. Paluma) por 110 dias em vasos com 2,8 dm-3 de substrato, em viveiro telado, em Taquaritinga-SP, no período de outubro de 2000 a abril de 2001. A escória promoveu um efeito favorável na reação do solo e na disponibilidades de Zn, Cu, Mn e B do solo. Houve efeitos quadráticos nas concentrações de Zn, Cu e Mn do solo, que, por sua vez, estiveram associadas às doses de escória superiores a 5,8; 6,3 e 7,5 g por vaso, respectivamente, enquanto, para o B, esse efeito foi linear. A saturação por bases do solo, entre 51 e 55%, resultou em maior disponibilidade dos micronutrientes Zn, Cu e Mn no solo, ao passo que, para o B, esse valor foi de 65%. da mesma forma que ocorreu no solo, a aplicação da escória apresentou efeitos quadráticos nos teores de Zn, Cu e Mn da parte aérea e das raízes das mudas de goiabeira, enquanto, para o B, esse efeito foi linear. Concluiu-se, portanto, que a escória se comportou como material corretivo da acidez e como fonte de micronutrientes.

Fatores climáticos na dinâmica populacional de Anastrepha spp. (diptera: tephritidae) e de Scymnus spp. (coleoptera: coccinellidae) em um pomar experimental de goiaba (Psidium guajava L.)

Este trabalho objetivou caracterizar a dinâmica populacional de Anastrepha spp. e de Scymnus spp. em pomar experimental semiorgânico de goiaba (Psidium guajava L.), em Pindorama-SP, na Agência Paulista de Tecnologia dos Agronegócios (APTA) e correlacioná-la com fatores meteorológicos. Para o levantamento da dinâmica populacional, os espécimes foram monitorados com armadilhas adesivas amarelas (25 cm x 9,5 cm), trocadas a cada 15 dias, no período de um ano (entre junho de 2009 e junho de 2010). Os insetos foram avaliados e quantificados no Laboratório de Seletividade Ecológica da UNESP-FCAV em Jaboticabal-SP. Observou-se a ocorrência de Anastrepha spp. e Scymnus spp. durante todo o período de amostragem. Com base nos resultados obtidos e nas condições de desenvolvimento do presente trabalho, foram possíveis as seguintes conclusões: a) Ocorre aumento na densidade populacional de Anastrepha spp. com o aumento das temperaturas mínima, média e máxima; b) Os picos populacionais de Anastrepha spp. ocorrem de janeiro a março e coincidem com o período de disponibilidade de frutos maduros no pomar de goiaba; c) Constatam-se as maiores ocorrências do predador Scymnus spp. no período de setembro a dezembro, e as menores ocorrências, em fevereiro e março; d) As precipitações não interferem na dinâmica populacional de Anastrepha spp. e de Scymnus spp..

Minimally processed guava fruits (Psidium guajava L.)

'Paluma' guavas, after internal quality evaluation using magnetic resonance tomography, were used to produce fresh-cut product. Fruits were peeled or not, cut in halves and seed removed, and they were packaged in polystyrene trays covered with PVC film or in a PET container with a lid. These packages were stored for 12 days at 5 degrees C, 10 degrees C and ambient temperature (22.6 degrees C). Tomography evaluation verified that impacts produced internal bruising with loss of cellular integrity and liquefication of the placenta tissues. Compression was more evident on the pericarp and cutting promoted superficial deformation. Storage temperature affected the weight loss, with fruit packaged in the polystyrene tray having a greater weight loss. The peeling did not influence weight loss. Product stored at 5 degrees C and 10 degrees C for 8 days had low microbial growth (< 10(3) UFC.g(-1)) and no coliforms. Rapid spoilage and a short shelf life (3-4 days) occurred when the product was stored at ambient temperature. Peeling reduced ascorbic acid concentration and total soluble solids. Use of calcium to protect fresh-cut products was not efficient. Calcium absorption capacity of 'Pedro Sato' guava was tested using Ca-45. Fruits treated with 2% CaCl2, with or without the radioisotope, were divided in four layers (epicarp, mesocarp, endocarp and seed) and analyzed for the total and Ca-45 calcium. It was observed that the applied calcium remained in superficial layers of fruits, which was confirmed by autoradiography. Internal layers did not contain Ca-45, indicating that calcium was not distributed into different parts of the fruit.

Effect of Controlled Atmospheres with Low Oxygen Levels on Extended Storage of Guava Fruit (Psidium guajava L. 'Pedro Sato')

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

Comportamento de chamamento de Thyrinteina arnobia (Stoll) (Lepidoptera: Geometridae) em Psidium guajava, Eucalyptus grandis e em dieta artificial

Este estudo teve como objetivos determinar e comparar o efeito de três dietas: Psidium guajava, Eucalyptus grandis e dieta artificial no comportamento de chamamento e no padrão temporal do comportamento de chamamento de fêmeas virgens de Thyrinteina arnobia (Stoll). Foram analisados os parâmetros: tempo médio para o início do chamamento, número médio de chamamento, tempo médio de cada chamamento e tempo médio total de chamamento. Os bioensaios relacionados ao comportamento de chamamento de fêmeas virgens foram realizados durante seis escotofases consecutivas e as observações tomadas a cada 5 min., a 22 ± 1ºC, 70 ± 5% de UR e 10h de escotofase. As fêmeas, independente da dieta analisada, apresentaram duas posições diferentes de chamamento. A maioria das fêmeas virgens iniciou o chamamento na 1ª hora da 1ª escotofase. O padrão de chamamento da fêmea individualizada foi característico de um padrão contínuo. O tipo de dieta oferecida na fase larval influenciou o início do comportamento de chamamento (pré-chamamento) e o tempo médio total de chamamento. O tipo de dieta também alterou a coloração da glândula de feromônio.

DSC studies on protein isolate of guava seeds Psidium guajava

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo fitoquímico de goiaba (Psidium guajava L.) com potencial antioxidante para o desenvolvimento de formulação fitocosmética

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermal study and physico-chemical characterization of some functional properties of guava seeds protein isolate (Psidium guajava)

The guava seed protein isolate ( PI) was obtained from the protein precipitation belonging to the class of the gluteline (Ip 4.5). The conditions for the preparation of the PI were determined by both the solubility curve and simultaneous thermogravimetry-differential thermal analysis (TG-DTA): pH 11.5, absence of NaCl and whiteners and T=( 25 +/- 3) degrees C. Under these conditions a yield of 77.0 +/- 0.4%, protein content of 94.2 +/- 0.3, ashes 0.50 +/- 0.05% and thermal stability, T= 200 degrees C, were obtained. The TG-DTA curves and the PI emulsification capacity study showed the presence of hydrophobic microdomains at pH 11.5 and 3.0 suggesting a random coil protein conformation and, to pH 10.0, an open protein conformation. The capacity of emulsification (CE), in the absence of NaCl, was verified for: 1 - pH 3.0 and 8.5, using the IP extracted at pH 10.0 and 11.5, CE >= 343 +/- 5 g of emulsified oil/g of protein; 2 - pH 6.60 just for the PI obtained at pH 11.5, CE >= 140 +/- 8 g of emulsified oil/g of protein.

Effect of light and temperature on seed germination in guava (Psidium guajava L. Myrtaceae)

The germination of seeds of Psidium guajava L. (Myrtaceae) is controlled by phytochrome. Guava seeds can germinate with at least one hour per day of irradiation of high red:far-red ratio light preceeded or followed by shade light, indicating that phytochrome B controls germination in these conditions. Under alternating temperatures, in a range of at least 5degreesC, seeds will germinate in darkness, suggesting that in gaps of the canopy, when seeds are covered by a thin layer of soil they will germinate once the alternating temperatures are experienced. Under these conditions phytochrome A is responsible for the control of guava seed germination.

Isolado protéico de semente de goiaba (Psidium guajava): caracterização de propriedades funcionais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Costs estimates and rentability of the guava culture (Psidium guajava L Paluma cv) in Monte Alto County, São Paulo State

This work intended to calculate the rentability of the guava culture Paluma cv. in Monte Alto region-SP, estimating the costs of the implantation, maintenance, production and the gross income of this culture in the first three years of cultivation. The production system utilized refers to the cultural treatments usually used in this culture in the region. The costs estimates were based on the total operational costs methodology used by the Agricultural Economics Institute (I.E.A.). The results obtained showed that the implantation and maintenance costs of the culture, in the two first years was R$7.402,3 l/alqueire*. Considering the possibility that in guava orchard, on irrigated conditions, reach in the fourthy year a productivity of 80t/alqueire and that the current price is R$0,20/kg, it is possible to estimate the gross income around of R$16.000,00/alqueire, resulting in a net income of R$9.497,06/alqueire.

Mineralogy and forms of potassium in red yellow latosol of a guava (Psidium guajava) tree orchard

A trial was conducted during 1994-95 to study the effect of potassium fertilization on a guava (Psidium guajava L.) culture for 3 years. The control plots (without K) showed fruit production and potassium exportation that did not agree with the levels obtained by chemical analysis of the soil. Physical, chemical, mineralogic and morphologic analyses were performed on the red yellow latosol to identify minerals able to supply potassium, with emphasis on the fact that guava trees have a considerably widespread root system. The results obtained confirmed the presence of minerals in this soil that can supply potassium to the trees through weathering. Feldspars were identified in the silt fraction and micas in the clay fraction by X-ray diffractometry. The determination of total potassium revealed that the silt fraction of the soil had the largest absolute amounts of potassium, followed by clay. However, in view of its greater content, clay was the fraction that contributed most to the total amounts of potassium detected.

Effect of potassium fertilization in 'Rica' guava (Psidium guajava) cultivation

A field experiment was conducted from 1989-90 to 1991-92 to study the effect of potassium fertilization on guava (Psidium guajava L.). using 1-year-old plants of 'Rica', grown in a Kanhapludalf soil in the Jaboticabal region in Brazil. During the first year the K doses used were: 0, 24.9, 49.8, 99.6, 149.4 and 199.2 g K/plant, which were doubled during the second year and tripled during the third. In the third year the increase in g level showed positive response in yield. About 90% of the maximum yield observed was associated with 527 g K/plant and with a leaf content of 18.9 g K/kg.

Antioxidant content in guava (Psidium guajava) and araca (Psidium spp.) germplasm from different Brazilian regions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Flutuação populacional de Meloidogyne enterolobii em pomar de goiabeira (Psidium guajava)

The objective of this work was to study the population fluctuation of Meloidogyne enterolobii in a commercial orchard of 'Paluma' guava with five years of age, under micro sprinkler irrigation system and usual practices for this crop. In the orchard, located in the municipality of Vista Alegre do Alto (SP) Brazil and infested by M. enterolobii, five plants exhibiting nematode symptoms were selected for monthly sampling from July 2007 to June 2008. Two single samples of rhizosphere soil and guava roots were collected from each plant, with the aid of hoe to a depth of 20 cm on the projection of the trees, forming a composite sample per plant. In nematology laboratory of Faculdade de Ciencias Agrarias e Veterinarias Universidade Estadual Paulista, eggs and second stage juveniles (J2) of M. enterolobii were extracted from the samples and quantified. There was not a marked seasonal variation in the nematode population in soil or roots, possibly as a result of the guava vegetation stimulated by irrigation or the presence of invasive plants during the experimental period. However, the soil density reached a peak in January, corresponding to the month of elevated rainfall and temperatures. In roots, there were two significant peaks, in February and a major peak in August. There was a negative correlation between nematode populations in soil and roots.