ABSTRACT. This study aimed to evaluate the effect of silicon and acibenzolar-S-methyl sources on the development of yellow melon (Cucumis melo L.) in the field and the occurrence of diseases in different years. The treatments consisted ofthe silicon sources Agrosilício® (3 g L−1), Rocksil® (3 g L−1), and Chelal® Si (2 L 100 L−1), the additional treatments acibenzolar-S-methyl (ASM) (2 mM) and the fungicide thiabendazole (400 mL 100 L−1), and a control (sterile distilled water). The following characteristics were evaluated: natural incidence of diseases; gas exchange: CO2 assimilation rate, transpiration, stomatal conductance, internal CO2 concentration, water use efficiency, instantaneous water use efficiency, and carboxylation; postharvest aspects: fruit weight, pulp thickness, pulp firmness, titratable acidity, pH, soluble solids, and vitamin C content; productivity; and the enzymatic activity of peroxidases, polyphenol oxidases, and phenylalanine ammonia-lyase. No significant response was observed for naturally occurring diseases. Treatments with Chelal®Si, Rocksil®, and Thiabendazole® increased photosynthetic and transpiration rates in the yellow melon. The silicon and ASM sources did not influence the physicochemical characteristics or the enzymatic activity of fruits. No effect was observed on the biometric characteristics, productivity, and chemical quality of fruits in both years of cultivation. Si sources increased photosynthetic rate and transpiration. However, no diseases were observed during the experimental period. Leaf spraying with silicon and acibenzolar-S-methyl sources did not influence the biometric characteristics and fruit production of yellow melon. The silicon and acibenzolar-S-methyl sources did not induce an increase in the enzymatic activity of peroxidases, polyphenol oxidase, and phenylalanine ammonia-lyase. Fruit production was higher in 2020.

Abstract The biological products use as a disease control alternative has been studied to reduce the impacts to the environment, men and animals, showing satisfactory results in postharvest. This study aimed to evaluate the biological agents effect in the control of Colletotrichum spp. and on postharvest quality of yellow passion fruit. The treatments were Trichoderma asperellum and Saccharomyces cerevisiae species at concentrations of of 0,5; 1,0; 1,5; 2,0 (g. L-1); Mancozeb fungicide (Dithane® 2 g i.a. L-1 water) and control (sterile distilled water). The fruits were immersed for 2 min in each treatment and then were drought. Five replications of three fruits were used to anthracnose severity analysis and yellow passion fruit physical-chemical quality in. The fruit inoculation was made with the deposition of Colletotrichum spp. on the surface of the fruit previously treated using holes which were made with the aid of a flamed perforator. In the research was evaluated: pH, total soluble solids and titratable acidity. Biological treatments reduced the anthracnose severity in yellow passion fruit. Fruit Post-harvest quality was not influenced by the biological control application. It is a viable alternative to postharvest management of anthracnose on yellow passion fruit under the studied conditions.

Resumo O uso de produtos biológicos como alternativa no controle de doenças tem sido estudado para diminuir os impactos ao meio ambiente, aos homens e animais, mostrando resultados satisfatórios na pós-colheita. O objetivo do trabalho foi avaliar o efeito de agentes biológicos no controle do Colletotrichum spp. e na qualidade pós-colheita em frutos de maracujazeiro-amarelo. Os tratamentos foram compostos por Trichoderma asperellum e Saccharomyces cerevisiae nas concentrações de 0,5; 1,0; 1,5; 2,0 (g. L-1); fungicida Mancozebe (Dithane® 2 g i.a. L-1 de água) e testemunha (água destilada esterilizada). Os frutos foram imersos durante 2 min em cada tratamento e, posteriormente, submetidos a secagem. Foram utilizadas cincorepetições de três frutos para as análises de severidade da doença e pós-colheita. Asvariáveis analisadas foram severidade da antracnose e qualidade química dos frutos. A inoculaçãodos frutos foi feita com a deposição de discos de micélio do Colletotrichum spp., e nasuperfície do fruto previamente tratado foram realizados orifícios com auxílio de um perfurador flambado.Foram avaliados os parâmetros químicos: pH, sólidos solúveis totais e acideztitulável. Os tratamentos biológicos reduziram a severidade da antracnose, e a qualidadepós-colheita dos frutos não foi influenciada pela aplicação do controle biológico. Ocontrole biológico constitui alternativa viável para o manejo pós-colheita da antracnose em maracujazeiro-amarelo, nas condições estudadas.

ABSTRACT The aim of the present study was to evaluate the effect of sanitizers on physicochemical characteristics, sanitary quality of ‘Paluma’ guava fruits during storage and in vitro control of Colletotrichum sp. Guavas ‘Paluma’ were treated with the sanitizers acetic acid, ascorbic acid, sodium hypochlorite, peracetic acid, hydrogen peroxide and thiabendazole fungicide, besides control (distilled water). Evaluations included fresh mass loss, firmness, pH, titratable acidity (TA), soluble solids (SS), SS/TA ratio, sanitary quality and in vitro control of Colletotrichum sp. The design was completely randomized, in a split-plot scheme, including seven treatments and five periods (three days), and four replicates of three fruits each. The sanitizers played an effective role in controlling mass loss and firmness of stored fruits. The pH of fruits was influenced by hydrogen peroxide (6th day), acetic acid and sodium hypochlorite (15th day). Acetic and peracetic acids reduced ascorbic acid loss in the fruits, indicating that sanitizers can be an alternative to increase the shelf life of fruits. Considering sanitary control, acetic acid and thiabendazole fungicide inhibited the growth of Colletotrichum sp. Acetic and peracetic acids and thiabendazole completely inhibited the growth of both isolates of Colletotrichum sp.

RESUMO O trabalho teve por objetivo avaliar o efeito de sanitizantes sobre as características físico-químicas, qualidade sanitária de frutos da goiabeira ‘Paluma’ durante o armazenamento e controle in vitro de Colletotrichum sp. As goiabas ‘Paluma’ foram tratadas com os sanitizantes ácido acético, ácido ascórbico, hipoclorito de sódio, ácido paracético, peróxido de hidrogênio e fungicida tiabendazol e controle (água destilada). Foram avaliadas a perda de massa fresca, firmeza, pH, acidez titulável (AT), sólidos solúveis (SS), relação SS/AT, qualidade sanitária e controle in vitro de Colletotrichum sp. O delineamento foi inteiramente casualizado, em esquema de parcelas subdivididas no tempo, sendo sete tratamentos e cinco períodos (três dias), com quatro repetições de três frutos cada. Os sanitizantes desempenharam papel efetivo no controle da perda de massa e firmeza dos frutos armazenados. O pH dos frutos foi influenciado pelo peróxido de hidrogênio (6º dia), ácido acético e hipoclorito de sódio (15º dia). Ácidos acético e paracético reduziram a perda de ácido ascórbico dos frutos, indicando que os sanitizantes podem ser uma alternativa para aumentar a vida útil dos frutos. No controle sanitário, o ácido acético e o fungicida tiabendazol inibiram o crescimento de Colletotrichum sp. Os ácidos acético e paracético e o tiabendazol, inibiram totalmente o crescimento de ambos isolados do Colletotrichum sp.

Resumen. Aunque los cactus están bien adaptados a los climas semiáridos brasileños, corren el riesgo de verse afectados por importantes problemas fitosanitarios, causando graves daños a su desarrollo. Por lo tanto, el diagnóstico correcto del agente etiológico es el paso más importante para apoyar la recomendación de estrategias de control eficientes. El objetivo de este estudio fue identificar agentes etiológicos causantes de enfermedades en cladodios de mandacaru (Cereus jamacaru) y mandacaru sin espinas (C. hildmannianus). Los cladodios se recolectaron de plantas infectadas en condiciones de campo en la comunidad de Sítio Paraíso, en el municipio de Prata, Estado de Paraíba, Brasil, y se enviaron para su análisis en el Laboratorio de Fitopatología/CCA/UFPB. Las estructuras fúngicas se observaron bajo el microscopio óptico, a partir de estructuras vegetativas y reproductivas de los hongos cultivados en medio PDA (papa-dextrosa-agar) a 25 ±2 ºC y bajo 12 h de fotoperíodo de luz. Los géneros que se observaron fueron: Aspergillus niger, Aspergillus sp., Cladosporium sp., Colletotrichum sp., Curvularia sp., Fusarium sp., Rhizopus sp. y Scytalidium lignicola. Los hongos Colletotrichum sp. y S. lignicola se consideran los primeros informes en cladodios de Cereus jacamaru y C. hildemannianus en el Estado de Paraíba, Brasil.

Abstract. Although cacti are well adapted to the climatic rigors of the Brazilian semiarid region, they run the risk of being affected by important phytosanitary problems. These problems cause serious damage during their development. Therefore, the correct diagnosis of the etiologic agent is the most important step to enable the recommendation of efficient control strategies. The objective of this study was to identify etiological agents that caused diseases in mandacaru cladodes (Cereus jamacaru) and mandacaru spineless (C. hildmannianus). The cladodes were collected from infected plants in the field in the Sítio Paraíso community, in the municipality of Prata, State of Paraíba, Brazil. They were analyzed at the Phytopathology Laboratory/CCA/UFPB. The fungal structures were observed under optical microscopy, from vegetative and reproductive structures of the fungi grown in PDA (potato-dextrose-agar) medium at 25 ±2 ºC and under a photoperiod of 12 h of light. The genera were observed: Aspergillus niger, Aspergillus sp., Cladosporium sp., Colletotrichum sp., Curvularia sp., Fusarium sp., Rhizopus sp. and Scytalidium lignicola. The fungi Colletotrichum sp. and S. lignicola are considered the first reports of episodes of Cereus jacamaru and C. hildemannianus in State of Paraíba, Brazil.

Cultivares de batata (Solanum tuberosum L.) têm mostrado degenerescência causada por vírus após ciclos sucessivos do uso de tubérculos de campos comerciais como material propagativo. Este trabalho verifica a ocorrência de infecção simples e mista de quatro vírus da batata na Paraíba e apresenta adequação da técnica de cultivo in vitro para obtenção de material livre de Potato virus Y (PVY), incluindo uso de microestacas, termo e quimioterapia. Plantas de batata do cv. Baraka foram submetidas à indexação sorológica pelo teste "direct antigen coating" ELISA. Utilizaram-se antissoros contra o PVY, Potato virus X (PVX), Potato virus S (PVS) e Potato leafroll virus (PLRV). Materiais com reação positiva para PVY foram submetidos a tratamentos visando à eliminação viral. Microestacas (1,0 cm de comprimento) com uma gema foram excisadas e inoculadas em meio nutritivo de Murashige & Skoog (MS), suplementado com 1,0 mg L-1 de cinectina, 0,00l mg L-1 de ácido naftaleno acético (ANA) e 0,1 mg L-1 de ácido giberélico (GA3). Termoterapia a 37ºC, durante 30 e 40 dias, promoveu a eliminação do PVY em 20,0 e 37,5% no material testado, respectivamente. A quimioterapia foi realizada com Ribavirin (RBV), 5-Azacitidina (AZA) e 3-Deazauridine (DZD). O RBV apresentou os melhores índices de erradicação de vírus com a obtenção de 55,5% de plantas sadias. Tratamentos simultâneos de termo e quimioterapia mostraram maior eficiência na eliminação viral, atingindo um percentual de plantas sadias da ordem de 83,3 com RBV, 70,0 com AZA e 50,0 com DZD.

Potato cultivars (Solanum tuberosum L.) have shown degeneration or run out caused by viruses after several cycles of propagation using seed tubers from commercial fields. This work reports the occurrence of single and mixed infections of four potato viruses in Paraíba-Brazil and presents a method for Potato virus Y (PVY) elimination, by using thermo-and chemotherapies. Plants of potato cv. Baraka were tested by direct antigen coating ELISA. Antisera against PVY, Potato virus X (PVX), Potato virus S (PVS), and Potato leafroll virus (PLRV) were used. Materials with positive reaction to PVY were treated for virus elimination. Single node cuttings (1.0 cm length) were excised and inoculated in Murashige & Skoog (MS) medium, supplemented with 1.0 mg L-1 of kinetin, 0.001 mg L-1 of naphthalene acetic acid (NAA) and 0.1 mg L-1 of gibberellic acid (GA3). The thermotherapy at approximately 37ºC, during 30 and 40 days, resulted in 20.0 and 37.5% PVY elimination, respectively. Chemotherapy was undertaken with Ribavirin (RBV), 5-Azacytidine (AZA), and 3-Deazauridine (DZD). The RBV showed the highest rate of virus eradication, with 55.5% virus-free plants. Simultaneous thermo and chemotherapy had higher efficiency for the elimination of PVY, reaching rates of healthy plants of 83.3% with RBV, 70.0% with AZA, and 50.0% with DZD.