Response of watermelon cultivars to gummy stem blight

Face à importância do crestamento gomoso do caule e à escassez de relatos da reação de genótipos de melancia na literatura nacional e internacional, este trabalho teve por objetivo avaliar a resposta de genótipos comerciais de melancia ao crestamento gomoso. No campo, estudou-se o nível de infecção nas folhas em delineamento de blocos ao acaso com nove cultivares de melancia e quatro repetições, com inoculação de duas plantas por parcela aos 43 dias após o plantio (DAP). Foram avaliadas as cultivares Crimson Sweet, Onix, Rubi, Safira, Eureka, Georgia, Sheila, Savana e Riviera. Em casa de vegetação, estudou-se a infecção no caule em vasos, com delineamento inteiramente casualizado, com três repetições, em esquema fatorial de 9 x 3, sendo o fator “a” = cultivares e o fator “b” = isolados. Foram avaliadas as mesmas cultivares do ensaio de campo, com inoculação artificial com disco de micélio aos 15 dias após a semeadura, quando do surgimento da primeira folha definitiva. Os isolados de D. bryoniae utilizados na inoculação das plântulas foram: UnB 76 (Melão-DF), UnB 75 (Melancia-PE) e UnB 81 (Abó- bora-DF). Dentre as cultivares avaliadas no campo, Riviera mostrou-se mais resistente e apresentou menores (P<0,05) índices de infecção foliar aos 74 e 79 dias após plantio (DAP), e também menor valor da área abaixo da curva de progresso de doença (AACPD). Foram altamente suscetíveis Crimson Sweet, Rubi, Onix e Safira, que apresentaram os mais altos níveis de infecção nas folhas aos 74 DAP e também altos valores de AACPD. Na avaliação da doença no caule, em casa de vegetação, Riviera também apresentou a menor AACPD (P<0,05). Foi significativa a correlação (r=0,77) entre a resposta das cultivares em campo (resistência das folhas) e em casa de vegetação (resistência no caule).Gummy stem blight, caused by Didymella bryoniae, is one of the most important watermelon diseases. Nevertheless, there are relatively few published studies on the response of watermelon genotypes to the disease. This paper reports results of studies on the response of commercially available watermelon cultivars to gummy stem blight. Leaf infection was studied in a randomized complete block field experiment with nine watermelon genotypes and four replicates. Two plants per experimental plot were inoculated 43 days after planting. Cultivars Crimson Sweet, Onix, Rubi, Safira, Eureka, Georgia, Sheila, Savana and Riviera were evaluated. Stem infection was studied in the greenhouse, in a completely randomized design, with three replicates, in a 9 X 3 factorial, where plant cultivars corresponded to factor “a” and pathogen isolates corresponded to factor “b”. The same nine cultivars were examined following artificial inoculation with mycelial disks inserted into stems, 15 days after planting date, when plants were at the first adult leaf stage. The D. bryoniae isolates were UnB 76 (Melon-DF), UnB 75 (Watermelon- PE) and UnB 81 (Pumpkin-DF). In the field experiment, Riviera was the most resistant genotype, with significantly (P<0.05) lower values of leaf infection at 74 and 79 DAP and the smallest area under disease progress curve (AUDPC). Crimson Sweet, Rubi, Onix and Safira were the most susceptible genotypes based on foliar disease levels 74 days after planting and also based on the AUDPCs. In the greenhouse, Riviera also presented the smallest (P<0.05) AUDPC in stems. A significant correlation (r=0.77) was detected between disease measurements in the greenhouse (stem response) and in the field (foliar response)

Didymella bryoniae resistance to fungicides in Brazil

O crestamento gomoso do caule (Didymella bryoniae) é uma das mais importantes doenças da melancia (Citrullus lanatus) no mundo. O controle químico, embora amplamente adotado, nem sempre pode impedir o progresso da doença no campo. A resistência do agente causal a alguns ingredientes ativos foi relatada na Europa, Japão e nos Estados Unidos, porém nenhum estudo foi feito no Brasil. Este trabalho descreve os resultados de três ensaios in vitro para resistência a fungicidas, medida pela taxa de crescimento micelial. No primeiro ensaio, sete isolados foram submetidos a nove fungicidas na metade da dose comercial recomendada. Evidência de resistência a Tiofanato metílico (TM), Carbendazim (CARB) (benzimidazóis) bem como a mistura Tiofanato metílico + Clorotalonil (TM + CHLO) foi detectada. Nenhuma resistência foi detectada contra Mancozebe, Difenoconazole, Tebuconazole e as misturas Mancozebe + Difenoconazole ou Trifloxistrobina + Propiconazole. O teste foi repetido com os mesmos sete isolados de D. bryoniae contra TM, CARB, TM + CHLO e Oxicloreto de Cobre a ¼, ½, 1 e 2 vezes a dose recomendada. Apenas Oxicloreto de cobre diminuiu consistentemente a taxa de crescimento micelial com o aumento da dose. TM não teve efeito na taxa de crescimento micelial em nenhuma concentração testada, e CARB e TM + CHLO mostraram mínimo efeito com o aumento da concentração do produto. Finalmente, 31 isolados de sete estados brasileiros foram testados para resistência a Tiofanato metílico na dose recomendada (490 ppm). Oitenta e um porcento dos isolados mostraram-se altamente resistentes. Isolados resistentes e sensíveis foram encontrados em uma mesma região geográfica. Considerando a prevalência de isolados resistentes a ambos TM e CARB, uma evidência de resistência cruzada, o uso de benzimidazoles não deve ser recomendado no controle do crestamento gomoso do caule. _________________________________________________________________________________ ABSTRACTGummy stem blight (Didymella bryoniae) is one of the most important diseases of watermelon (Citrullus lanatus) wordwide. Chemical control, although widely adopted, cannot always avoid disease progress in the field. Resistance of the causal agent to some active ingredients has been reported in Europe, Japan and in the United States, but no such study has been done in Brazil. This work reports results of three in vitro assays for fungicide resistance, as measured by the rate of mycelial growth. In the first test, seven isolates were evaluated against nine fungicides at half the recommended commercial doses. Evidence of resistance to Methyl Thiophanate (TM) and Carbendazim (CARB) (Benzimidazoles) as well as to the mixture of Methyl-Thiophanate and Chlorotalonil (TM+CHLO) was detected. No resistance was suggested to Mancozeb, Difenoconazole, Tebuconazole and the mixtures Mancozeb + Difenoconazole or Trifloxistrobine + Propiconazole. The test was repeated with the same seven isolates of D. bryoniae against TM, CARB, TM+CHLO and Copper Oxichlorate at ¼, ½, 1 and 2 times the recommended doses. Only Copper Oxichlorate consistently caused a decrease in the mycelial growth rates with increasing doses. TM had no effect on the mycelial growth rates at any of the concentrations tested, and CARB and TM+CHLO showed very minor effects with increasing product concentrations. Finally, a collection of 31 isolates from seven Brazilian states was tested for resistance against TM at the recommended dose (490 ppm). Eighty-one per cent of the isolates, from most Brazilian states, proved to be highly resistant. Resistant and sensitive isolates were found in the same geographic regions. Considering the prevalence of isolates resistant to both TM and CARB, an evidence of cross-resistance, the use of benzimidazoles should be avoided for gummy stem blight control

Dissertações

Resumos de dissertações de mestrado em Educação Especial, defendidas na Universidade Lusófon

Melon fruit quality front mildew incidence and management of nitrogen and potassium topdressing

This work aimed to evaluate the application effect of different dosages of nitrogen and potassium topdressing on mildew severity and on yield and fruit quality of melon. The three cultivars, Jangada, Gaucho Casca de Carvalho and Gaucho Redondo Cone Sul were evaluated in Cerrado (savannah) and floodplain areas. At 34 days after sowing (DAS) the topdressing treatments with different dosages of nitrogen and potassium were applied. The mildew severity estimation started at 56 DAS and was performed in five-days intervals until the harvesting of the fruits. The yield and physicochemical characteristics of the collected fruits were evaluated at harvest. There was no significative interaction among nitrogen and potassium topdressing, the cultivars and cultivated areas. However, there was significative differences when the factors were analyzed in separate. The cultivar Gaucho Redondo Cone Sul showed a significant linear increase in the area under the disease progress curve and higher productivity on cerrado compared to the remaining cultivars. The cultivar Gaucho Casca de Carvalho produced heavier and with higher °Brix fruits on cerrado. It is possible to conclude that the applied topdressings did not reduce the mildew severity in all tested cultivars, but they increased the yield in the floodplain area without modifying the physicochemical characteristics of the pulp on the evaluated melon fruits.This work aimed to evaluate the application effect of different dosages of nitrogen and potassium topdressing on mildew severity and on yield and fruit quality of melon. The three cultivars, Jangada, Gaucho Casca de Carvalho and Gaucho Redondo Cone Sul were evaluated in Cerrado (savannah) and floodplain areas. At 34 days after sowing (DAS) the topdressing treatments with different dosages of nitrogen and potassium were applied. The mildew severity estimation started at 56 DAS and was performed in five-days intervals until the harvesting of the fruits. The yield and physicochemical characteristics of the collected fruits were evaluated at harvest. There was no significative interaction among nitrogen and potassium topdressing, the cultivars and cultivated areas. However, there was significative differences when the factors were analyzed in separate. The cultivar Gaucho Redondo Cone Sul showed a significant linear increase in the area under the disease progress curve and higher productivity on cerrado compared to the remaining cultivars. The cultivar Gaucho Casca de Carvalho produced heavier and with higher °Brix fruits on cerrado. It is possible to conclude that the applied topdressings did not reduce the mildew severity in all tested cultivars, but they increased the yield in the floodplain area without modifying the physicochemical characteristics of the pulp on the evaluated melon fruits

Efficiency of application of Trichoderma on the physiological quality and health of cowpea seeds

One of the main causes of low productivity of cowpea crops in Brazil is the use of low quality seeds. Low quality seeds have a high degree of infestation by phytopathogens, mainly fungi. Seed treatment with biological control agents, such as fungi of the genus Trichoderma, is a useful alternative to reduce or inhibit the transmission of diseases via seeds. In view of the above, this study aims to evaluate the physiological and sanitary quality of cowpea seeds treated with conidia of Trichoderma sp. (1.2, 2.4, 4.8 and 9.6 x 108 CFU g-1). We evaluated the germination and the sanity of seeds, length of seedling radicles, and production of indole acetic acid (IAA) by fungi. The experimental design was completely randomized in all experiments. In general, there was a predominance of Fusarium spp. and Rhizoctonia solani. The treatment of seeds with the conidia of Trichoderma sp. was positive for the parameters related to germination and radicle length of cowpea beans up to the concentration 4.8 x 108 CFU g-1. We conclude that the application of Trichoderma sp. was efficient in reducing the incidence of Fusarium spp., and promoted the germination and elongation of the radicle in cowpea.One of the main causes of low productivity of cowpea crops in Brazil is the use of low quality seeds. Low quality seeds have a high degree of infestation by phytopathogens, mainly fungi. Seed treatment with biological control agents, such as fungi of the genus Trichoderma, is a useful alternative to reduce or inhibit the transmission of diseases via seeds. In view of the above, this study aims to evaluate the physiological and sanitary quality of cowpea seeds treated with conidia of Trichoderma sp. (1.2, 2.4, 4.8 and 9.6 x 108 CFU g-1). We evaluated the germination and the sanity of seeds, length of seedling radicles, and production of indole acetic acid (IAA) by fungi. The experimental design was completely randomized in all experiments. In general, there was a predominance of Fusarium spp. and Rhizoctonia solani. The treatment of seeds with the conidia of Trichoderma sp. was positive for the parameters related to germination and radicle length of cowpea beans up to the concentration 4.8 x 108 CFU g-1. We conclude that the application of Trichoderma sp. was efficient in reducing the incidence of Fusarium spp., and promoted the germination and elongation of the radicle in cowpea

Chemical control of watermelon gummy stem blight

O objetivo deste trabalho foi estudar o efeito de fungicidas e da adubação de cobertura na severidade do crestamento gomoso do caule, em melancia (Citrullus lanatus). Foram conduzidos dois ensaios fatoriais em campo, no Projeto Formoso, Tocantins, em delineamento de blocos ao acaso com quatro repetições, e parcelas experimentais de 30 x 10 m. Para o ensaio I, os tratamentos (fator a) constaram dos seguintes ingredientes ativos de fungicidas/100 l de água ou ha: (1) mancozeb (MANC)-160,2 ml, (2) tiofanato metílico (TM)-49 g, (3) carbendazim-500 ml, (4) tebuconazole-20 g, (5) difenoconazole (DIFE)-75 ml, (6) tiofanato metílico-40 g + clorotalonil-100 g, (7) oxicloreto de cobre-168 g, (8) trifloxistrobina-87,5 g + propiconazole-87,5 g, (9) mancozeb-80 ml + difenoconazole-37,2 ml e (10) testemunha. No fator b, estudou-se a adubação de cobertura (N-K) nos níveis de 30-20 e 90-60 kg/ha. A severidade da doença nas folhas foi avaliada com uma escala de notas de 0 a 9. Para o ensaio II, repetiram-se os tratamentos do fator a, enquanto o fator b (níveis de adubação), foram: 60-40 e 120-80 kg/ha de N-K. Nos dois ensaios as menores Áreas Abaixo da Curva de Progresso de Doença (AACPD) foram obtidas com MANC + DIFE, TM + clorothalonil, MANC, trifloxistrobina + propiconazole e oxicloreto de cobre. A adubação de cobertura não influenciou a severidade da doença. As produtividades mais altas foram obtidas com TM + clorotalonil, MANC + DIFE e MANC que diferiram estatisticamente do DIFE, testemunha e trifloxistrobina + propiconazole

Geração e seleção de percursos de mercadorias em entrepostos de grande dimensão na SONAE

Trabalho realizado na SONAE, orientado por Gina Sarabando CasalDissertação de mestrado integrado. Mestrado Integrado em Engenharia Industrial e Gestão. Faculdade de Engenharia. Universidade do Porto. 201

Antracnose foliar e produtividade de sorgo cultivado em áreas de várzea tropical e terras altas

O sorgo é o quinto cereal mais produzido no mundo e um fator limitante à sua produção é a incidência de doenças, tais como a antracnose (Colletotrichum graminicola). Este trabalho teve por objetivo avaliar a incidência e o progresso da antracnose e a produtividade de diferentes genótipos de sorgo em condições de várzea tropical e terras altas. Para tal, foram utilizados três genótipos de sorgo: DOW 1F305, A9735R e BRS 310. Aos 30 dias após o plantio (DAP), o experimento foi implantado com a aplicação da adubação de cobertura (40 e 80 kg ha-1 de nitrogênio). A avaliação da severidade da antracnose foi realizada utilizando uma escala de notas. Na coleta, determinou-se a produtividade dos genótipos com base na massa dos grãos. Foram registrados diferentes padrões de progresso da antracnose nos genótipos avaliados quando comparadas as duas áreas de estudo. Houve diferença na produtividade de grãos em resposta às doses de nitrogênio aplicadas. A suscetibilidade do genótipo BRS 310 pode estar associada principalmente às condições de cultivo, tendo em vista sua maior sensibilidade à antracnose foliar quando cultivado em terras altas. O genótipo DOW 1F305 foi menos sensível à antracnose e apresentou menor produtividade de grãos independente da condição de cultivo

A Fauna de Morcegos Fósseis como Ferramenta na Caracterização de Paleoambientes Quaternários.

This study proposes to reconstruct the paleoenvironment from Quaternary sites of the caves in the sertão baiano and Lagoa Santa region during the Pleistocene. The paleofauna of bats from these sites were compared to the extant fauna of 25 localities, representing most important Neotropical biome. This study was possible because all bat fossil species from both sites were elements of the extant Neotropical fauna, excepting Desmodus draculae. Because bats are considered goodenvironmental definers, the association of extant and fossil fauna permits the recognition of similar environments. The similarity between faunas was analyzed by Jaccard index with a posterior grouping analysis by UPGMA. The paleofauna of Lagoa Santa matched to Caatinga fauna, suggesting a dry and open environment adjacent to the Lagoa Santa cavesduring the Pleistocene. The paleofauna of sertão baiano caves matched to neither of the analyzed faunas. Most authorssuggest that fossil record of the sertão baiano caves represents a faunal mixture. The dissimilarity between the paleofaunaof bats from the sertão baiano caves and the other analyzed faunas resulted of this study is in agreement to the argumentof a faunal mixture represented by the former

Relationship between free-time physical activity and sleep quality in brazilian university students

Poor sleep quality and low or no free-time physical activity (FTPA) practice are highly prevalent among university students, but the association between these conditions is still unclear. This cross-sectional study analyzed the relationship between FTPA and sleep quality. An online questionnaire was conducted with university students from a public university in southern Brazil in 2019. The weekly frequency of FTPA was self-reported, and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression and ANCOVA models were performed and adjusted for confounders. Among the 2,626 students analyzed, 52.2% did not practice the FTPA, and 75.6% had poor sleep quality (PSQI > 5). In the adjusted analysis, practicing FTPA 4¿7 times/week was associated with poor sleep quality (odds ratio = 0.71; 95% confidence interval = 0.52, 0.97) compared with not practicing FTPA. In addition, those who practiced FTPA had significantly lower means of the global PSQI, subjective sleep quality and duration, sleep disturbances, and daytime dysfunction scores than those who did not practice FTPA. In conclusion, the FTPA may contribute to better sleep quality among university students