Luciana Cordeiro do Nascimento

Caracterização morfológica de frutos e sementes e desenvolvimento pós-seminal de Tamarindus indica L. - Leguminosae: caesalpinioideae

Tamarind (Tamarindus indica L.) is a fruit tree native of tropical Africa, belonging to the Leguminosae family and nowadays is spread along tropical regions of the world. Fruit and seed morphologic characterization is important for species identification and has been used in studies on seed germination and vigor. The main aim of this research work was to describe fruit, seed and seedlings morphology as well as characterizing its germination process. Fruit traits analyzed were type, color, dimensions, texture and consistency of pericarp, dehiscence and number of seeds for fruit. On the other hand, seed traits were scored as to color, dimensions, texture and consistency of the teguments, shape, edges, position of hilum and other structures and embryo characteristics. Seedlings were recorded when protophylls development had already been complete. Radicle, collect, hypocotyl, cotyledons, epicotyl and protophyll have been described and illustrated. T. indica presents an indehiscent fruit with dimensions around 7.3 and 9.2cm and containing 1-11 seeds. The embryonic axle is axial and invagined and is inserted into cotyledons. Seed germination is an epigeal-type and seedlings present protophyll composites with 6 and 9 pairs of opposing and glabrous and small leaflets.

Avaliação da atividade de indutores de resistência abiótica, fungicida químico e extratos vegetais no controle da podridão-negra em Abacaxi 'Pérola'

Black rot of pineapple, caused by Chalara paradoxa (De Seyn.) Sacc., is a postharvest disease responsible by high losses on fruits destined to the fresh market and to the processing industry. Penetration of fungus inside cells occurs through wounds and stem cutting, causing infection. The objective of this work was to evaluate the effect of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple control. 32 fruits of pineapple cv perola were used. They were disinfested with sodium hypochlorite (commercial product) at 4% for 5 minutes. After drying at room temperature, fruits were treated, by spraying, with: 1) Distilled water (control), 2) Derosal 3) Bion® (Acibenzolar-S-methyl); 4) Ecolife®; 5) Agro-Mos®; 6) Allium sativum extract at 20%; 7) A. cepa at 20% and 8) Azadirachta indica at 20%. Treated fruits were incubated on humid chamber with polyethylene bags during 24 hours before inoculation procedure using a mycelia disk added to a wound at the epidermic area of the fruit. Evaluation of disease progress was done by a disease index: 1- no symptoms, 2- black rot on epidermis reaching 1-5 simple fruits, 3- black rot on epidermis reaching 6-10 simple fruits, 4- internal brown yellow rot, 5- black rot and disintegration of internal area in more than 50%. The experimental design was a completely randomized with eight treatments and five replicates, using general linear models with multinomial distribution and the averages were compared by Scott-Knott test at 5%. The best results were found in the Ecolife treatment with longer fruit life span and less severity in the symptoms of the disease.

Manejo do míldio e ferrugem em videira com indutores de resistência: produtividade e qualidade pós-colheita

Mildew and rust diseases are among the main diseases of the vine crop in Brazil causing great losses in pre- and post-harvest conditions. Studies involving different aspects of induced resistance have been developed with the aim of promoting the reduction of pesticides use in the field. In this research, the effect of elicitors on the control of mildew and rust in vine cultivar Isabel was evaluated. Seven treatments were tested: Citric bioflavonoids (1.5 L ha-1), citric bioflavonoids + potassium phosphite (1.5 L ha-1 + 130 g 100 L-1), potassium phosphite (130 g 100 L-1), control treatment was sprayed with water (T), fungicide (metyran + pyraclostrobin) (2 kg ha-1), aluminum silicate (1%) and Saccharomyces cerevisiae (1.5 L ha-1), four replications and five plants per replication. The disease indexes were determined using progress curve of disease in grapevine according PIF (Integrated Fruits Production) for four periods (0 to 42 days post pruning - DAP, 43 to 77 DAP, 78 to 129 DAP and 0 to 129 DAP). The yield components and quality aspects were evaluated at 126 DAP. The use of S. cerevisiae and fungicide promoted the highest mildew control. However, the use of S. cerevisiae decreased the yield. No significant effects of the elicitors were observed on rust incidence.

Efeito de extratos vegetais no controle de Fusarium oxysporum f. sp tracheiphilum em sementes de caupi

A fusariose e uma doenca de grande importância para a cultura do feijoeiro em virtude da reducao da produtividade. O controle da doenca vem sendo realizado com aplicacoes indiscriminadas de fungicidas quimicos, acarretando problemas ao homem e ao meio ambiente. Objetivou-se, no presente trabalho, avaliar o efeito de extratos vegetais no controle de Fusarium oxysporum f. sp tracheiphilum, proveniente de sementes de caupi, comparando-se com o efeito do fungicida quimico. Utilizaram-se extratos de alho, angico e manjericao, isolados ou combinados entre si e ou em associacao ao fungicida Mancozeb. Uma aliquota de 50 µL de cada tratamento foi adicionada em orificio feito no centro das placas de Petri com BDA, sobre o qual depositou-se um disco de micelio do fungo. Avaliou-se durante sete dias, medindo-se o crescimento micelial do patogeno. Sementes de caupi foram desinfestadas com hipoclorito de sodio a 4,0%, semeadas em sacos de polietileno contendo solo autoclavado. Oito dias apos germinacao, efetuaram-se ferimentos no colo das plântulas, aplicando-se suspensao de esporos do fungo (1,4 x 10-5 con/mL). As avaliacoes de severidade da doenca foram realizadas diariamente durante 30 dias apos a inoculacao, utilizando-se escala de notas. Os extratos combinados de alho + manjericao e angico + manjericao nao inibiram o crescimento micelial do fungo, enquanto o extrato de manjericao isoladamente, proporcionou o menor crescimento micelial, indicando a acao fungicida e inibitoria desse tratamento sobre o fungo F. oxysporum f. sp tracheiphilum nas condicoes analisadas. O fungicida Mancozeb + o extrato de angico proporcionou menor media de severidade nas plantas avaliadas.

Controle de Colletotrichum gloeosporioides em mamoeiro, utilizando extratos vegetais, indutores de resistência e fungicida

This present work had as objective to evaluate the control of papaya diseases using natural extracts ( Allium sativum L., Anadenanthera peregrina L. Speng, and Ocimum basilicum L.), natural oils ( Gossypium hirsutum L. and Bixa orellana L.), resistance inducers (Bion ® , Ecolife ® and Agro-mos ® ), and a chemical fungicide (Mancozeb/Dithane). Experiment I was conducted to evaluate the inhibitory potential of the treatments on Colletotrichum gloeosporioides mycelial growth in vitro ; in Experiment II, artificial inoculation of fungus was performed on healthy papaya fruits, and the severity of stem-end rot was evaluated using a disease index; and in Experiment III, treatments were applied on papaya seedlings artificially inoculated with C. gloeosporioides , and anthracnose was evaluated by means of a disease index. Obtained results showed that extracts of Anadenanthera and Allium were responsible for lower mycelial growth in vitro , and Bion ® was efficient for papaya stem-end rot. In papaya seedlings, the effects of garlic, angico and Bion® differed significantly from the rest, with Bion ® showing the best results for anthracnose control. Papaya seeds were not affected by C. gloeosporioides . Thus, alternative control to stem-end rot and anthracnose on papaya with natural products and resistance inducers should be an option viable for agrochemicals substitution

Levantamento e avaliação da incidência das doenças da mandioca no estado da Paraíba

To survey and quantify the incidence of the diseases affecting cassava (Manihot esculenta) in commercial crops of the state of Paraiba - Brazil, samplings were conducted in 21 municipalities at four microregions of the state during the first semester of 2011. The detected diseases were brown leaf spot (Cercosporidium henningsii), white leaf spot (Phaeoramularia manihotis), anthracnose (Colletotrichum gloeosporioides f. sp. manihotis) and root rot (Fusarium oxysporum). The incidence varied, and the highest indexes were found for the municipalities of the microregions of Curimatau Ocidental, Sape and Brejo Paraibano. Brown leaf spot occurred in all evaluated municipalities, followed by white leaf spot, which showed inferior percentage of affected plants. Anthracnose was detected for around 70% of the evaluated municipalities but had reduced incidence. The highest incidence of root rot caused by F. oxysporum was observed for the city Imaculada, microregion of the Serra do Teixeira.

Eficiência de óleos essenciais na qualidade sanitária e fisiológica em sementesde feijão-fava (Phaseolus lunatus L.)

The Phaseolus lunatus L. species, popularly known as lima bean, is one of the alternative sources of income and food for the population of Northeast Brazil. One of the problems is the diseases that cause great losses in seed production. This study evaluated the effectiveness of essential oils of copaiba, clove, and basil in reducing the incidence of fungi associated with lima bean seeds, as well as the effect on their physiological quality. The treatments consisted of essential oils of copaiba, clove, and basil at concentrations of 0; 1; 1.5; and 2 mL. L-1 and fungicide (Captan®). A total of 200 seeds were used per treatment. To analyze the sanitary quality of the seeds, the method used was incubation in petri dishes containing a double layer of filter paper moistened with distilled sterilized water at a temperature of 20 ± 2°C, for seven days. The physiological quality of the seeds was determined by testing their germination, emergence, and vigor. For the germination test, the method used was a roll of Germitest paper. For the emergence, the seeds were sown in plastic trays containing washed sterilized sand in greenhouse conditions. After nine days, the vigor was determined based on the results of germination and emergence speed rates; length of the aerial part, primary root, and seedling; and dry matter content of the aerial part, roots, and seedlings of the lima beans. The experimental design was completely randomized in a simple factorial arrangement (3x4)+1 (essential oils x concentrations + fungicide) with four replications of 50 seeds. The essential oils of copaiba and basil considerably reduced the percentage of incidence of the fungi associated with lima bean seeds. The essential clove oil at 2 mL. L-1 reduced the physiological quality of the lima bean seeds.

Extração da mucilagem em sementes de Genipa americana L. visando o potencial fisiológico

Belonging to the Rubiaceae family, the fruit-bearing plant, genipapo (G. americana L.), is widely distributed in humid tropical and subtropical regions of Latin America. The seeds present a thick adherent mucilage which can be harmful to germination, favouring the development of microorganisms; action is therefore needed for its removal. Given the above, the aim of this study was to evaluate the physiological potential of batches of genipapo seeds under different methods of extraction of this mucilage. Fruits of four genipapo mother plants from the town of Areia in the state of Paraiba, Brazil, were submitted to the following methods for the extraction of mucilage from the seeds: manual by sieve, running water and sand; fermentation; centrifugation and H2SO4. The physiological potential of the seeds was evaluated for water content, germination, first count and germination speed index, length and dry weight, seedling emergence and health test. The experimental design was completely randomised with mean values being compared by Tukey test (p<0.05). Seed moisture content was similar between batches. The different methods for extracting the mucilage from the genipapo seeds under evaluation did not affect germination, maintaining viability; when evaluated for vigour however, the seeds extracted by sieve were seen to be superior compared to the other methods. The method for the removal of mucilage from genipapo seeds using a sieve and sand gave seeds with high physiological potential, having no influence on the quality of health of those seeds.

Inoculação de Curvularia eragrostidis em inhame (Dioscorea alata) cv. São Tomé

Objetivou-se selecionar o método de inoculação de Curvularia eragrostidis em mudas de inhame (Dioscorea alata) cv. São Tomé para a determinação da infecção e do período de latência. O isolado de C. eragrostidis foi obtido a partir de folhas de inhame com sintomas da doença. Plantas com 45 dias de idade, cultivadas em casa de vegetação, foram inoculadas com o patógeno da seguinte forma: T1 – Suspensão de esporos (1x10 conídios mL); T2 Discos de colônia de 10 mm fixados com fita adesiva (dois na face abaxial e um na face adaxial); Leite, R.P.; Nascimento, L.C.; Oliveira, M.D.M. Inoculação de Curvularia eragrostidis em inhame (Dioscorea alata) cv. São Tomé. Summa Phytopathologica, v.44, n.3, p.281-282, 2018.

Alternativas no controle da mancha marrom de alternaria em tangerineira ‘Dancy’

A tangerineira ‘Dancy’ apresenta características desejáveis como cor, aroma, sabor e ampla aceitação pelo mercado consumidor. Trata-se de uma variedade bastante produzida no estado da Paraíba, porém, suscetível a mancha marrom de alternária (MMA), causada por Alternaria f. sp. citri, responsável por comprometer a qualidade dos frutos nas regiões produtores de tangerineiras. E para prevenir essa doença, tem-se ampliado pesquisas com o uso de produtos alternativos. Portanto, objetivo do trabalho foi determinar o potencial do extrato de Caesalpinia ferrea e da Quitosana no manejo da MMA em frutos de tangerineira ‘Dancy’. Os frutos foram desinfestados e imersos em extrato de C. ferrea nas concentrações 0; 10; 100; 500 e 1000 μg/mL e a Quitosana a 0,5; 1,0; 1,5 e 2,0 g/L. Após 24 h da aplicação dos Demartelaere, A.C.F.; Nascimento, L.C.; Abraão, P.C.; Gomes, R.S.S. Marinho, C.O.; Nunes, M.C. Alternativas no controle da mancha marrom de alternaria em tangerineira ‘Dancy’. Summa Phytopathologica, v.44, n.2, p.164-169, 2018.