Herbal medicines with anthelmintic effects are alternatives for the sustainable control and prevention of disease caused by gastrointestinal parasites. The nanoencapsulation of essential oils has been proposed to enhance the absorption of their constituents and improve their efficacy. The present study aimed to evaluate the efficacy of free and nanoencapsulated Eucalyptus citriodora essential oil (EcEO) on the control of gastrointestinal nematodes of small ruminants in vitro and in vivo. Chitosan was used as a matrix for the formulation of a nanoemulsion. Chromatographic and physico-chemical analyses of EcEO were performed. Egg hatch (EHT) and larval development (LDT) tests were conducted to evaluate the effectiveness of nanoencapsulated and free EcEO on the eggs and larvae of Haemonchus contortus. Acute toxicity of free and nanoencapsulated EcEO was evaluated using mice. Finally, nanoencapsulated EcEO efficacy on the control of gastrointestinal nematodes was calculated by fecal egg count reduction test (FECRT) treating 30 sheep naturally infected with 250 mg/kg of free and nanoencapsulated EcEO. In vitro tests were analyzed by an analysis of variance (ANOVA) followed by comparison with the Tukey test. The efficacy of FECRT was calculated by the BootStreet program through arithmetic average, using the formula 100 (1-XT/XC). To compare the differences between epg, the data were transformed to log(x+1) and subjected to an ANOVA to compare the significant differences between groups by Tukey's. The level of significance was P<0.05. The free (4 mg/ml concentration) and nanoencapsulated (2mg/ml concentration) EcEO inhibited larvae hatching by 97.2% and 92.8%, respectively. Free and nanoencapsulated EcEO at 8 mg/ml inhibited larval development by 99.8% and 98.1%, respectively. In the acute toxicity test, the LD10 and LD50 of free EcEO was 1999 and 2653 mg/kg, respectively, while the LD10 and LD50 of nanoencapsulated EcEO was 1121 and 1681 mg/kg, respectively. Nanoencapsulated and free EcEO reduced FEC similarly by 40.5% and 55.9%, respectively at 10 days post-treatment. Nanoencapsulated EcEO did not obtain the expected efficacy in vivo.

RESUMO Botrytis cinerea é um dos mais importantes patógenos da videira nas regiões de altitude em Santa Catarina. O presente trabalho objetivou avaliar a influência de diferentes épocas de desfolha no progresso da podridão de B. cinerea na videira Cabernet Os ensaios foram conduzidos nas safras 2014/2015 e 2015/2016, em um vinhedo comercial, situado a 1230m (a.n.m.), no munícipio de São Joaquim, SC (28º 17’ 39” S e 49º 55’ 56” W). Foi utilizado a variedade Cabernet Sauvignon, enxertada sobre o porta-enxerto Paulsen 1103, conduzida em espaldeira, com espaçamento de 3,0m x 1,5m e cobertura anti-granizo. Os tratamentos consistiram na realização da desfolha nos estádios fenológicos: plena florada, grão chumbinho, grão ervilha, virada de cor, 15 dias após a virada de cor e plantas não submetidas ao manejo da desfolha. A doença foi quantificada quinzenalmente nos cachos, no início dos primeiros sintomas até a colheita. As curvas de progresso da doença foram elaboradas e comparadas de acordo com: início do aparecimento dos sintomas, tempo para atingir a máxima incidência e severidade da doença, incidência e severidade máxima da doença, área abaixo da curva de progresso da incidência e severidade da doença. Os resultados desse estudo evidenciam que desfolhas precoces devem ser recomendadas, como estratégia de manejo de controle de B. cinerea da videira Cabernet Sauvignon cultivada em regiões de elevada altitude de Santa Catarina.

Pratylenchus brachyurus has become one of the most serious problems in Brazilian soybean fields. The use of resistant cultivars has long been considered the most practical and effective means of controling nematodes. Nonetheless, to our knowledge, there is no study on the genetic parameters associated with resistance of soybean to P. brachyurus in Brazil. This study was undertaken to estimate resistance genetic parameters under glasshouse conditions. In both trials, we found high phenotypic and genotypic variability, either for reproductive factor or number of nematodes per fresh gram of roots. Furthermore, high coefficients of genotypic determination and variation index were obtained. These results suggest that breeding for this feature can be relatively easy. The next logical step will be to conduct inheritance genetic studies.

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Pratylenchus brachyurus was identified morphologically from root samples collected from a macadamia field in the municipality of Charqueada, located in southeastern São Paulo, Brazil. Low numbers of the nematode were recovered from samples collected from asymptomatic macadamia trees. To our knowledge, this is the first record of P. brachyurus on macadamia in Brazil and worldwide.