Resíduos da agroindústria de chá preto como substrato para produção de mudas de hortaliças

O objetivo do trabalho foi determinar o efeito do resíduo do chá preto como substrato na produção de mudas de alface, tomate e pepino. Para tal, foram conduzidos testes de germinação e ensaios de crescimento empregando, respectivamente, extrato aquoso e diferentes tipos de resíduo. Nos testes de germinação, sementes de alface, tomate e pepino foram colocadas em bandejas sobre papel de filtro umedecido com água ou extrato aquoso na concentração de 1, 5 e 10%. Nos ensaios de crescimento, sementes das mesmas espécies foram colocadas em bandejas contendo: 1. vermiculita; 2. resíduo decomposto mais vermiculita; 3. resíduo decomposto e 4. resíduo bruto lavado mais vermiculita. O resíduo decomposto foi obtido após processo de decomposição do resíduo bruto e o resíduo bruto lavado foi obtido a partir da lavagem do resíduo bruto em água. Nos testes de germinação e ensaios de crescimento, foi adotado o delineamento experimental inteiramente casualizado com quatro tratamentos e quatro repetições com 30 sementes cada. Os resultados indicaram que o extrato aquoso inibiu a germinação das sementes e o crescimento das plântulas de alface, tomate e penino. O uso do resíduo bruto lavado mais vermiculita reduziu a emergência das plântulas. O resíduo decomposto e o resíduo decomposto mais vermiculita estimularam a emergência e o crescimento das plântulas. O processo de decomposição tornou viável a utilização do resíduo da indústria de chá preto como substrato para produção de mudas de hortaliças.

Produção e heterose de híbridos experimentais de pepino do tipo japonês

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

Avaliação de porta-enxertos para pepino tipo japonês

A enxertia de pepino híbrido do tipo japonês em aboboreira tem por objetivo principal o manejo de doenças causadas por fungos de solo, consequentemente obter maior produtividade, além de frutos menos cerosos. Neste trabalho estudou-se o comportamento da cultivar Rensei, avaliando-se o desenvolvimento vegetativo das mudas, a produtividade e as características dos frutos das plantas enxertadas em diferentes porta-enxertos, em comparação com as não enxertadas. O trabalho foi realizado sob estufa do tipo túnel alto, com as plantas conduzidas em recipientes plásticos, de julho/96 a julho/97, em Piracicaba - SP. Os tratamentos foram os seguintes: T1 testemunha (planta não-enxertada); T2 enxertia em abóbora Menina Brasileira; T3 enxertia em abóbora híbrida Ikki; T4: enxertia em abóbora-de-moita Novita; T5 enxertia em abóbora híbrida Tetsukabuto; T6 enxertia em abóbora híbrida Kirameki. A porcentagem de pegamento da enxertia só não apresentou valores superiores a 83,3% quando se utilizou abóbora Menina Brasileira. Foram obtidos frutos mais brilhantes e com pouca cerosidade, de interesse comercial, na enxertia em Ikki e Kirameki. Nestes porta-enxertos, seguidos por Tetsukabuto, houve maior produção em peso e número de frutos por planta.

Redução da área foliar e o rendimento do pepino japonês

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

Avaliação do potencial alelopático, atividade antimicrobiana e antioxidante dos extratos orgânicos das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae)

Este trabalho apresenta os resultados de atividade alelopática, antimicrobiana e antioxidante dos extratos orgânicos (hexano, acetato de etila e metanol) das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae). Para alelopatia, foi estudado o desenvolvimento de Cucumis sativus (pepino), sendo avaliados o comprimento da raiz principal, o número de raízes secundárias e o comprimento do hipocótilo. Os dois primeiros parâmetros foram afetados por todos os três extratos testados enquanto o comprimento do hipocótilo só não foi afetado pelo extrato acetato de etila. Quanto à atividade antimicrobiana, avaliada pelo ensaio de CIM, o extrato hexânico apresentou inibição moderada frente ao Staphylococcus aureus (0,9 mg mL-1) e forte ao Enterococcus hirae (0,5 mg mL-1). O extrato acetato de etila apresentou forte atividade frente Candida albicans (0,3 mg mL-1) enquanto o extrato metanólico não mostrou-se ativo para os microrganismos testados. Por outro lado, o extrato metanólico apresentou a maior capacidade de seqüestrar radicais livres (Concentração Efetiva 50%-CE50 =102,0 ± 56,9 mg mL-1, com TCE50 = 30 min) no ensaio com DPPH (2,2-difenil-1-picril-hidrazila) e o maior teor de compostos fenólicos (116,2 ± 83,0 mg ácido gálico g amostra-1), avaliado pelo ensaio de Folin-Ciocalteau.

Novos Registros sobre Meloidogyne mayaguensis no Brasil e Estudo Morfológico Comparativo com M. incognita

Almeida, E.J., P.L.M. Soares, A.R. Silva & J.M. Santos. 2008. New records on Meloidogyne mayaguensis in Brazil and comparative study with M. incognita. Meloidogyne mayaguensis is the plant-parasitic nematode responsible for a great impact on guava production in Brazil, since it has been the cause for eradication of thousand of hectares of guava plantations in the Northeastern region. In the present study, this species was detected in soybean fields of Ituverava municipality, São Paulo state, and in different vegetable crops (lettuce, cucumber, pepper and cherry tomato) in Chapada dos Guimaraes municipality, Mato Grosso state, causing root galls and other symptoms. The species was identified on the basis of the perineal pattern of females, and on the morphology and morphometry of anterior region of males. Isozyme phenotype for esterase was used for confirmation. This constitutes the first report on the occurrence of M. mayaguensis on lettuce, cucumber, pepper and cherry tomato cultures in Mato Grosso state and the first one in soybean in São Paulo state. It was found that morphological features of male anterior region and female perineal pattern are enough for the safe distinction between M. mayaguensis and M. incognita.

AVALIACAO DE BERGAPTENO 3CH E 6CH NA PROTECAO DE PEPINEIROS (CUCUMIS SATIVUS) CONTRA INTOXICACOES POR ESSA MESMA SUBSTANCIA

Authors report trial with bergapten using homeopathic preparations and the protection of cucumber seedlings (Cucumis sativus) against intoxications by the same substance and assess the positive results obtained.

Qualidade fisiológica de sementes de pepino cv. pérola, em função da idade e do tempo de repouso pós-colheita dos frutos

This work was carried out at the Fazenda Experimental Lageado, at Botucatu, SP, to evaluate the physiological quality of cucumber (Cucumis sativus L.), seeds harvested at different fruit maturity stages and post-harvest resting periods. Fruits of cultivar Pérola were harvested at 6 ages (20, 25, 30, 35, 40 and 45 days after anthesis) and they were stored at room temperature for 0, 5, 10 or 15 days before seed extraction. After this, seeds were fermented for 2 days, washed and dried. External visual characteristics of fruits and seeds were observed at harvest. Seed quality was evaluated as for moisture, dry matter content, dimensions, germination, and vigour. Results showed that seed germination and vigour increased in fruits aging from 20 to 40 days. Post-harvest periods improved seed quality of 20-day old fruits not reaching the seed quality levels observed in 40 or 45-day old fruits, without post-harvest resting period. Seeds from fruits at 25, 30 and 35 days of age, with 10 or 15 days of post-harvest resting period reached the same quality levels of seeds from fruits with 40-45 days old.

Inhibitory effects of jackbean (Canavalia ensiformis L.) leaf residues on germination and vigour of crops and weeds

The effects of jackbean leaf residues incorporated in the soil on germination and seedlings growth of cucumber, radish and some weeds was examined. Trials were carried out under greenhouse conditions to (a) determine the amount of incorporated residue that is inhibitory to two test plants, (b) to determine if decomposition time changes the inhibitory levels of jackbean residues on test plants and (c) to determine the amount of residue that is inhibitory to the weed species. Jackbean leaf residues incorporated in soil at concentration of 2% or higher and allowed to decompose for a period of 0 to 2 weeks before sowing, reduced the initial growth of cucumber and radish and at different concentrations, reduced germination and growth of three weed species. These results suggest the presence of allelopathic components in Jackbean leaves that could affect seed germination and seedling development.

Occurrence, distribution, and relative incidence of five viruses infecting cucurbits in the state of Sao Paulo, Brazil

Cucurbits species grown in 38 of 40 agricultural regions in the state of Sao Paulo, Brazil, were surveyed for the relative incidence of Cucumber mosaic virus (CMV), Papaya ringspot virus-type W (PRSV-W), Watermelon mosaic virus-2 (WMV-2), Zucchini lethal chlorosis virus (ZLCV), and Zucchini yellow mosaic virus (ZYMV) during May 1997 and June 1999. Samples from 621 plants, representing eight cultivated species, six wild species, and one commercial hybrid (Cucurbita moschata x C. maxima), were analyzed by plate trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA). PRSV-W and ZYMV were the most frequently found viruses, accounting for 49.1 and 24.8%, respectively, of 605 samples tested. ZLCV, CMV, and WMV-2 were detected in 7.8, 6.0, and 4.5% of 612, 497, and 423 samples tested, respectively. Double infection was found in 97 samples, and triple infection was found in 10 samples. Quadruple infection was detected in one C. pepo sample. Plants that were symptomatic but negative by PTA-ELISA might be due to abiotic agents, infection by virus for which antiserum was not available, such as Squash mosaic virus, or infection with an as yet uncharacterized virus.

Efeito alelopático de extratos de parte aérea de barbatimão [Stryphnodendron adstringens (Mart.) Coville] na germinação e desenvolvimento da plântula de pepino

Stryphnodendron adstringens (Mart.) Coville (barbatimão), belonging to Mimosaceae family; it is used as ornamental and the wood is used in civil buildings, edification in wet places, lathe and joinery jobs, being very used also in home-made medicine against hemorrhage, diarrhea, hemorrhoids, conjunctivitis, injury cleaning, uterus hemorrhage, ulcerous hurt and excessive oily skin. The objective of this research was to determine the allelopathic potential of an aqueous extract, boiled or not of S. adstringens (Mart.) Coville, in the Cucumis sativus germination and initial development. Thus, the aqueous vegetable extract was extracted from the shoot, which was triturated in 1L of distilled water to 100g of leaf, being the extract filtrated and separated in boiled and not boiled. The treatments used were distilled water (0%) and boiled and not boiled extracts, in the concentrations of 50 and 100%. The cucumber seeds were put to germinate in Gerbox, having filter paper as substrate, which was wet with 25mL from different treatments, in constant temperature of 25°C. The reading germination was accomplished in breaks of 24 hours, for a period of five consequently days after the beginning of the experiment, considering germinated the seeds that showed 2mm of root, approximately. To dry matter determination, the seedlings with five days after the germination were separated in shoot and root, dried during three days to a constant weight in a 60°C forced draft oven. Through results, it can be concluded that the extract of S. adstringens affected more the Cucumis sativus seedling development than the germination, and it didn't show difference if boiled or not.

Fusarium solani f. sp. passiflorae: A new forma specialis causing collar rot in yellow passion fruit

The aim of this study was to characterize a Fusarium population obtained from yellow passion fruit (YPF) with collar rot using pathogenicity, morphocultural characteristics and molecular tests. Pathogenicity and disease severity were assessed in six plant species: YPF, zucchini, tomato, bean, soya bean and cucumber. Potato dextrose agar medium (PDA) was used to determine mycelial growth at five temperatures (15-35°C). The colour produced by isolates was also determined on PDA at 25°C. Synthetic nutrient agar medium was used to evaluate: (i) type of mycelium and phialides; (ii) size, shape and number of septa from conidia; and (iii) production of chlamydospores and perithecia. Molecular tests consisted of sequencing the ITS-5·8S rDNA region and elongation factor 1α (EF-1α) gene. The isolates caused large lesions on YPF, zucchini and tomato, with YPF having the highest mean disease severity and being the only one that showed wilt symptoms and death of the plant. Thus the isolates showed host specificity. Maximum mycelial growth occurred at 25°C and the predominant colour was bluish-white. The isolates produced long phialides, dense aerial mycelium, oval microconidia with a mean size of 9·5 × 2·6 μm, macroconidia of 32·7 × 3·4 μm with 3·3 septa, and chlamydospores; only one isolate lacked perithecia. Phylogenetic trees of the ITS region and EF-1α gene showed that isolates from YPF formed a distinct group within the F. solani group and the formae speciales of F. solani. It is proposed to name all isolates from YPF as F. solani f. sp. passiflorae. © 2013 British Society for Plant Pathology.

Rootstocks resistant to Meloidogyne incognita and compatibility of grafting in net melon

Due to the few studies about grafting in net melon, in order to obtain better control of soil pathogens, the aim of the present study was to evaluate 16 genotypes of Cucurbitaceae: Benincasa hispida, Luffa cylindrica, pumpkin 'Jacarezinho', pumpkin 'Menina Brasileira', squash 'Exposição', squash 'Coroa', pumpkin 'Canhão Seca', pumpkin 'Squash', pumpkin 'Enrrugado Verde', pumpkin 'Mini Paulista', pumpkin 'Goianinha', watermelon 'Charleston Gray', melon 'Rendondo Gaucho', melon 'Redondo Amarelo', cucumber 'Caipira HS' and cucumber 'Caipira Rubi', regarding to compatibility of grafting in net melon and resistance to Meloidogyne incognita, based on the reproduction factor (RF), according to Oostenbrink (1966). To assess resistance, the seedlings were transplanted to ceramic pots and inoculated with 300/mL eggs and/or second stage juveniles of M. incognita. At 50 days after transplanting, the plants were removed from the pots and the resistance was evaluated. The compatibility between resistant rootstock and grafts of net melon was determined by performing simple cleft grafting, in a commercial net melon hybrid of great market acceptance and susceptible to M. incognita (Bonus no. 2). The genotypes Luffa cylindrica, pumpkin 'Goianinha', pumpkin 'Mini-Paulista', melon 'Redondo Amarelo', watermelon 'Charleston Gray' are resistant to the nematode M. incognita. The better compatibilities occurred with the rootstocks melon 'Amarelo', which presented 100% of success, followed by pumpkin 'Mini-Paulista' with 94%. On the other hand, Sponge gourd, watermelon 'Charleston Gray' and pumpkin 'Goianinha' showed low graft take percentages of 66%, 62% and 50%, respectively.

Estudo da lixiviação de herbicidas utilizados na cultura da cana-de-açúcar com plantas bioindicadoras

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

Silício e excesso de amônio e de nitrato em plantas de cana-deaçúcar e de pepino

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