Edna Peixoto da Rocha Amorim

Ação antagônica de rizobactérias contra Phytophthora parasitica e p. citrophthora e seu efeito no desenvolvimento de plântulas de citros

The antagonism of Pseudomonas putida biotype A (C1-1B), P. putida biotype B (Santa Barbara), P. fluorescens (C2-8C and RA2), Bacillus subtilis (OG and RC2) and Flavobacterium sp. (CIS/NA) against Phytophthora parasitica and P. citrophthora, rhizobacteria, agent of root rot of Citrus sp., was evaluated by mycelial growth inhibition (paired culture) and reduction of disease percentage in seedlins (seeds treatment). In a preliminary screening, 33 bacteria isolates were tested. The citrus seeds were immersed in the bacteria suspensions (109 ufc/ml) and then sown in plastic tubes containing natural soil, previously infested with the pathogen at a concentration of 50 ml of suspension/kg of soil. The evaluation of the disease percentage was carried out after 15 days. In vitro, the isolates of bacteria RC2, OG, CIS/NA and C1-1B were the most effective inhibitors of the mycelial growh of Phytophthora. In greenhouse conditions all the isolates reduced the disease percentage. Beneficial effects were obtained with the isolates OG, RC2, CiS/Na and C1-1B in relation to plant growth.

Avaliação de diferentes meios de cultura na esporulação de Scytalidium lignicola

Scytalidium lignicola causes black root rot and stem rot on cassava plants. The sporulation of S. lignicola was evaluated in 8 different culture media as following: potato-dextrose-agar (PDA), soybean-agar, oat-extract-agar, potato-sucrose-agar (PSA), coconutextract-agar, V-8 juice-agar, cassava-agar and corn meal-agar, under light alternation (12h light/12h dark) at three different temperatures 25, 28 and 30oC. Discs measuring 5mm were removed from the border of a 5-days old fungus culture in PDA. These discs were transferred to the center of Petri dishes containing 15mL of each media with selective inhibitors. After 5 days of incubation, the spores were counted in a Neubauer chamber. The experiment was installed using a randomized block design in a factorial 8 media x 3 temperatures scheme. It was observed that the only significant factor was the media culture, V-8 juice-agar , PDA, cassava-agar, oat-extract-agar, PSA, and soybean-agar media gave the best fungus sporulation without significant difference among them. There was no significant difference between the corn meal-agar and coconutextract-agar media for fungus sporulation. On these media, fungus sporulation was the lowest compared to the other media.

Atividade antibacteriana de óleos essenciais e extratos vegetais sobre o desenvolvimento de Ralstonia Solanacearum em mudas de bananeira

This study aimed to evaluate the activity of different concentrations of essential oils and plant extracts to the control of Ralstonia solanacearum. Different concentrations of the following essential oils were evaluated: citronella, Eucalyptus citriodora, clove and ginger: 1.25%, 3.5%, 3.75% and 5%, respectively. The extracts evaluated were from clove, ginger, cinnamon and Sao Caetano melon: 5%, 10%, 15% and 20%, respectively measuring the halo of inhibition of bacteria after 48 hours. The treatments with eucalyptus oil and extracts of Sao Caetano melon, clove and cinnamon did not differ from the control. The extract of ginger and the oils of citronella, clove and ginger inhibited the growth of R. solanacearum in all concentrations tested. Clove oil was the best treatment, followed by extract of ginger. Seedlings of banana were sprayed with citronella and cloves oils (3.75%), ginger oil (3.75%) and extract of ginger (20%), 10 ml of each solution per plant. After eight days the seedlings were inoculated with the pathogen (108 CFU/mL). The citronella oil provided the best result, with 100% control of the disease, but the leaves showed symptoms of phytotoxicity. The oil and extract of ginger were similar in effectiveness of moko control (50%), and cloves oil showed lower efficiency (25%).

Ocorrência de Doenças em Bananeiras no Estado de Alagoas

Cultivation of banana is an important source of income for small and middle farmers of the state of Alagoas. Most plantations are located in rain forest and nearshore costal areas, with suitable weather conditions for occurrence and development of diseases. The objective of this work was to survey the diseases of banana occurring in production areas of the state of Alagoas. This work was conducted during 2006 and 2007, by means of visits to farms and assessment of infected plant materials, in 60 banana production areas, distributed in fourteen counties of the state of Alagoas. The material collected was analyzed in laboratory for identification of pathogens associated with diseases. In this survey several diseases caused of fungi and nematodes were observed. It was found the diseases: yellow sigatoca (Pseudocercospora musae) (Zimm.) Deighton; Deightoniella spot (Deightoniella torulosa) (Syd.) Ellis; Cordana spot (Cordana musae Zimm), the three diseases presented in all areas surveyed; Chloridium spot (Chloridium musae Stahel), occurring only in areas with humidity and associated at others leaf spots; the spot Exosporella found only at Santana do Mundau; Phytonematoses causaded by Rhadophulus similis, Helicotylenchus multicinctus and Pratylenchus sp. found only in some counties; panama disease (Fusarium oxysporum f.sp. cubense) found only in four areas in the outh of the state and bacterial wilt (Ralstonia solanacearum) (Smith) Yabuuchi et al. (race 2), found only in three areas. Even though panama disease and moko disease (Ralstonia solanacearum race 2) were found in low incidence, these diseases still are considered major problems in banana plantations in the State Alagoas.

Ocorrência de Curvularia lunata e Curvularia eragrostidis em Tapeinochilus ananassae no estado de Alagoas

empregou-se omeio de batata-dextrose-agar (BDA), onde fragmentos de bracteasdesinfetados foram incubados a 25°C em fotoperiodo de 12/ 12 horasclaro/escuro.A patogenicidade do isolado foi efetuada em inflorescenciaspreviamente limpas e desinfestadas em hipoclorito de sodio. Discosde BDA contendo micelio dos patogenos foram inseridos emincisoes efetuados nas bracteas das inflorescencias. As testemunhasreceberam discos de meio de cultura, utilizando-se a mesmametodologia. As plantas inoculadas e as testemunhas forammantidas em câmara umida por 72 horas, a temperatura ambiente.As inflorescencias inoculadas com os isolados de

Ocorrência de Fusarium solani f. sp. piperis em Piper nigrum no estado de Alagoas

The pepper-of the-kingdom (Piper nigrum L.) it is a climbing plant, pertaining plant to the Piperaceae family. It is originary the southeastern Asian, being most common and important of the spices. Seedling death, also known for rottenness of the foot and rottenness of the root is the main illness of the culture, restricted occurrence to Brazil. Isolated of Fusarium sp., found contamined plants of bragantina pepper-do-kingdom cv. in the city of Uniao dos Palmares in Alagoas, was characterized morphologycament and had its pathogenicity confirmed in changes of this host. The macroconidia slightly curved, typically canoe-shaped, hyaline with three the five septate, measuring 30,5 - 26,5 x 6,3 - 4,9 im. Microconidia hyaline, unicellulars, ellipticals or allantoises measuring 16,6 - 4,9 x 6,5 - 3,3 im. The chlamydospores had been abundant in half potato-dextrose-agar. The isolated one was identified as to Fusarium solani f. sp. piperis being about the first story of this parasitic on plants in pepper-of the-kingdom in the state of Alagoas.

Phytophthora palmivora, agente da podridão de raiz e frutos de mamoeiro no Estado de Alagoas

The papaya (Carica papaya) is one of the most important tropical fruit crops and its fruit contribute with a production of 1.65 millions tons/year in Brazil. An isolated of Phytophthora sp. gotten from papaya fruits cv. Hawaii, in the state of Alagoas, was characterized morphologically and its pathogenicity to this fruits and seedling was confirmed. In a V-8 medium, the sporangiophores presented to be slim, simple or little ramified, while the sporangia presented ovoid to ellipsoid, prominently papillae and one short pedicel in the basal portion, measuring in average 37,68 x 27,52 (m. Through the characteristics presented by the isolated and the induced symptoms, the causal agent was identified as Phytophthora palmivora. Despite of this disease already occurring in other states like in Bahia, Espirito Santo, Sao Paulo, Pernambuco and Para, this is the first report of Phytophthora palmivora on papaya in the state of Alagoas, Brazil.

Detecção de Begomovirus em maracujazeiro (Passiflora edulis Sims) no Estado de Alagoas

Passion fruit is a crop of great economic importance in Tropical countries, distinguishing Brazil as the greatest producer. The present work reports the infection of passion fruit by a virus belonging to the genus Begomovirus, family Geminiviridae in the state of Alagoas, Brazil. Infected plants showed symptoms of yellow mosaic, drastic reduction of growth and leaf area. The DNA extracted from symptomatic plants was used as template in PCRs, containing the pairs of primers PAL1v1978 and par1C496 or PBL1v2040 and PCRc1, which direct the amplification of regions of approximately 1.2 kb DNA-A and 0.6 kb DNA-B, from begomovirus genome, respectively. Fragments of the components A and B with expected size were amplified from samples of symptomatic plants, confirming the infection by a begomovirus.

Avaliação da eficiência de extratos de plantas nativas da caatinga sobre o controle da podridão seca (Lasiodiplodia theobromae) em cachos da videira cv. Itália

ABSTRACT This study aimed to verify L. theobromae control by using plant extracts. Initially, L. theobromae mycelial growth inhibition was evaluated on Petri dishes containing PDA medium supplemented with extracts of “boldo baiano”, “jurema preta”, “pata-de-vaca” and “pau-ferro” at the concentrations of 10, 20 and 30% for all extracts. Afterwards, two in vivo experiments were carried out to evaluate the direct and protective effect of the plant extracts tested in vitro on Peixinho, G.S.; Santos, C.M.G.; Ribeiro, V.G.; Amorim, E.P.R.; Bispo, J.S.; Carvalho,V.N.. Evaluating the efficiency of extracts from plants native to caatinga on dry rot ( Lasiodiplodia theobromae ) control in bunches of grape cv. Italia. Summa Phytopathologica, v.43, n.2, p.155-157, 2017. dry rot intensity in bunches of grape cv. It alia, using the concentration of 30%, while sterile distilled water (ADE) was adopted as control. Results showed that extracts of “pau-ferro”, “pata-de-vaca”, “jurema preta” and “boldo baiano” at concentrations of 30% inhibited mycelial growth by 85.6, 83.3, 85.6 and 88.9%, respectively; however, the tested extracts were not efficient in inhibiting the disease incidence and severity.

Ação do óleo essencial de menta (Mentha arvensis) sobre o patógeno Lasiodiplodia theobromae em cachos de videira cv. Itália

ABSTRACT The presence of Lasiodiplodia theobromae (dry rot) on the vine, in irrigated areas of the Brazilian semi-arid region, has been very aggressive, infecting several plant parts. Essential oils show efficient disease control, both for their fungitoxic action, which inhibits mycelial growth and spore germination, and for the presence of elicitor compounds. Thus, this study aimed to obtain L. theobromae control by using the oil from mint ( Mentha arvensis ). The mycelial growth of L. theobromae was analyzed on Petri plates containing potato-dextrose-agar medium supplemented with the essential oil at the following concentrations: 0; 0.25; 0.5; 1.0; 1.5; 2.0% of mint oil. To evaluate the direct effect of the essential oil on the disease development, the grape bunches were inoculated with the pathogen and, after 4 h, sprayed with solutions containing Peixinho, G.S.; Ribeiro, V.G.; Amorim, E.P.R. Action of the essential oil of mint ( Mentha arvensis ) on the pathogen Lasiodiplodia theobromae