ABSTRACT. The aim of this work was to verify the potential of chelate-based products containing calcium, copper, manganese, and zinc for the management of Pantoea ananatis, Puccinia polysora, Cercospora zeae-maydis, Exserohilum turcicum, Diplodia macrospora, and Pseudomonas avenae in crop maize growth in the summer season, as well as their influence on agronomic characteristics. The treatments included commercial chelate-based products of amino acids with the elements calcium (15%), copper (5%), manganese (15%), and zinc (10%) at doses of 0.5 kg ha-1, 0.3 L ha-1, 0.4 kg ha-1, and 1 L ha-1, respectively; fungicides (20% azoxystrobin and 8% cyproconazole at a dose of 0.3 L ha-1 + 25% propiconazole at a dose of 0.4 L ha-1); and water. The tests were carried out under field conditions for two consecutive years with two simple hybrids. The plant height, stem diameter, number of rows per ear, number of grains per ear row, productivity and mass of one thousand grains, as well as the severity of leaf diseases, were all evaluated, and chemical analysis of the leaves was performed. In the 2016/2017 growth season, for the number of rows per ear and number of grains per row, the fungicide treatment showed the highest values, whereas for the mass of one thousand grains and productivity, the chelate treatments did not differ from the fungicide treatment and were different from the water treatment. In the 2017/2018 growth season, for the mass of one thousand grains and yield, only the fungicide treatment was different from the water treatment. For all the chelates studied for both hybrids, there was no difference in nutrient content before and after foliar application. It can be concluded that calcium, copper, manganese, and zinc products may influence agronomic traits but not the severity of the diseases evaluated in these two hybrids of maize under the edaphoclimatic conditions in which the study was carried out.

ABSTRACT Nematode control strategies are limited and alternative control is demanded. The main aim was to evaluate control potential of Hohenbuehelia spp. (Hohenbuehelia mastrucata, Hohenbuehelia barbatula, Hohenbuehelia bullulifera, Hohenbuehelia portegna, Hohenbuehelia petaloides and Hohenbuehelia paraguayensis) and Trichoderma koningiopsis against Meloidogyne javanica in bean plants in greenhouse. The parameters evaluated were the number of galls and egg masses which were evaluated in three root regions: basal, intermediate and tip; nematode reproduction factor; vegetal growth parameters (plants height on V1, V2, V4, and R5 growth stages, root length, dry weight of root and aerial part dry weight); Treatments were composed by individual interactions of each fungal isolate with 4,000 eggs of M. javanica, having a total control (bean) and a partial control (bean + nematode) arranged in completely randomized design with four repetitions. Data were tested by Scott–Knott (5%). For vegetal growth parameters, there was only significance for dry weight of roots. All species were able to control nematodes.

Abstract The objective of this work was to evaluate the fungitoxic effect of the aqueous extracts of Baccharis trimera on the mycelial growth of Colletotrichum lindemuthianum 89 race, as well as its effect on the accumulation of phaseolin in hypocotyls of different cultivars and common bean varieties. It was obtained 20% aqueous extract from plants collected in municipalities of the Western Region of Paraná. Blocks containing C. lindemuthianum mycelium were transferred to Petri dishes containing medium with the different extracts and incubated at 25 °C. The colonies diameter was measured until the 12th day. Effects of aqueous extracts on phaseolin production was evaluated in hypocotyls of Carioca, Cnpf 8104, Soberana, Tibatã, Uirapurú cultivars, as well as Rosinha and Vermelho varieties. Each one cultivar and variety hypocotyl was transferred separately to test tubes containing 500 μL of 20% aqueous extracts. Sterile water, Bion®, and UV was used as controls. The phaseolin production was measured in spectrophotometer [280 nm]. Results of the evaluation of the antifungal activity of aqueous extracts of Baccharis sp. specimens collected indicate that approximately 50% of the samples presented capacity to reduce between 74 and 92% of C. lindemuthianum growth. Cultivar Tibatã and Vermelho variety showed greater sensitivity over the applied treatments. Results of fungal filtrates and vegetal aqueous extracts presented a low capacity to induce the production of phaseolin in hypocotyls.

RESUMO Devido ao impacto ambiental gerado pelo uso indiscriminado de fungicidas, busca-se novas alternativas para o controle das doenças, como a utilização de nutrientes, os quais podem inibir o desenvolvimento de patógenos ou diminuir a suscetibilidade da planta a doenças. O objetivo deste trabalho foi verificar se produtos à base de cálcio, cobre, manganês e zinco inibem a germinação de esporos de Puccinia sorghi, Cercospora sp. e Exserohilum turcicum. Foram realizados dois experimentos: o primeiro com meio de cultura ágar-água, onde os tratamentos e os esporos foram colocados no mesmo momento; e o segundo utilizando folhas de milho como substrato, onde os tratamentos foram administrados zero, uma, duas, três, quatro e cinco horas após os esporos serem pulverizados. Utilizou-se como tratamentos produtos à base de cálcio, cobre, manganês e zinco na forma de quelato 15%, 5%, 15% and 10%, fungicida (estrobilurina e triazol, 20% azoxistrobin and 8% ciproconazole + triazol, 25% propiconazole) e água destilada. Realizou-se a contagem dos esporos 24 horas após a aplicação dos tratamentos. Para o primeiro ensaio, os quelatos apresentaram, em média, redução de 39%, tanto na germinação de esporos de P. sorghi quanto de Cercospora sp.. Para o segundo experimento, os mesmos patógenos tiveram redução média de 52%, 59%, 77%, 87%, 81% e 64% para P. sorghi e 40%, 33%, 17%, 18%, 4% e 2% para Cercospora sp., ambos nos tempos, zero, 1, 2, 3, 4 e 5 horas após o tratamento, respectivamente. Para E. turcicum não houve efeito inibitório em nenhum ensaio. Conclui-se que os metais na forma de quelato testados apresentam atividade antifúngica a P. sorghi e Cercospora sp..

ABSTRACT Due to the environmental impact generated using fungicides, new alternatives for disease control have been arising, such as the use of nutrients that may act on the development of certain pathogens or decrease the host susceptibility to diseases. The objective of this work was to verify if chelates of calcium, copper, manganese and zinc inhibit the germination of Puccinia sorghi, Cercospora sp. and Exserohilum turcicum spores. Two experiments were carried out: the first with agar-water culture medium, where the treatments and spores were placed at the same moment and the second using corn leaves as substrate, where treatments were administered zero, one, two, three, four and five hours after the spores are sprayed. Calcium, copper, manganese and zinc products were used as treatments in the form of chelate 15%, 5%, 15% and 10%, fungicide (strobilurine and triazole, 20% azoxistrobin and 8% ciproconazole + triazole, 25% propiconazole) and distilled water. The spores were counted 24 hours after the application of the treatments. In the first experiment, chelates showed an average reduction of 39% in both germination of P. sorghi and Cercospora sp. spores. For the second assay, the same pathogens had a mean reduction of 52%, 59%, 77%, 87%, 81% and 64% for P. sorghi and 40%, 33%, 17%, 18%, 4% and 2% for Cercospora sp., both at zero, 1, 2, 3, 4 and 5 hours after treatment, respectively. E. turcicum had no inhibitory effect under treatments. The metal-chelates tested were fungitoxic to P. sorghi and Cercospora sp. spores.

RESUMO Extratos vegetais podem induzir mecanismos de resistência de plantas em função da presença de compostos com características eliciadoras. O objetivo deste estudo foi avaliar o efeito do extrato bruto de alecrim nas concentrações 0%; 1%; 2,5% e 5% sobre a atividade de peroxidase, polifenoloxidase e fenilalanina amônia-liase (FAL) em soja inoculada com Macrophomina phaseolina. Foram retiradas amostras nos tempos 0, 36, 72, 120, 168, 216 e 264 h após o tratamento. Nas amostras retiradas do colo das plantas, para peroxidase, as concentrações mais elevadas do extrato proporcionaram dois picos de indução. Houve constante incremento na atividade de polifenoloxidase desde 36 até 120 h após o tratamento para a concentração 5%. Para FAL apenas a concentração 5% promoveu incremento 83% e 130% maior nos tempos 168 e 216 h após o tratamento, respectivamente. Para as atividades na raiz, peroxidase novamente apresentou dois picos de incremento para concentração 5%, a polifenoloxidase foi 426% maior na concentração 5% às 216 h após o tratamento e a atividade de FAL apresentou incremento de 340% no tempo 216 h após o tratamento com 5% do extrato. Estes resultados indicam o potencial do extrato de alecrim em induzir a atividade de enzimas de defesa em colo e raiz de soja.

ABSTRACT Plant extracts may induce resistance mechanisms in plants due to the presence of compounds with eliciting characteristics. The aim of this study was to evaluate the effect of rosemary crude extract at the concentrations 0%; 1%; 2.5% and 5% on the activity of peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase (PAL) in soybean plants inoculated with Macrophomina phaseolina. Samples were collected at 0, 36, 72, 120, 168, 216 and 264 hours after treatment. Considering the samples collected at the collar region of plants, for peroxidase, the highest concentrations of the extract provided two induction peaks. There was a constant increase in polyphenol oxidase activity from 36 to 120 hours after treatment at 5% concentration. For PAL, only the concentration of 5% led to increases 83% to 130% higher at 168 and 216 hours after treatment, respectively. For the activities in the root, peroxidase again showed two increment peaks at 5% concentration; polyphenol oxidase was 426% higher at 5% concentration at 216 hours after treatment and PAL activity showed an increase of 340% at 216 hours after treatment with 5% extract. These results indicate the potential of rosemary extract to induce the activity of defense enzymes in the collar region and in the root of soybean plants.