Extrato de Coffea racemosa como alternativa no controle do bicho-mineiro do cafeeiro

Abstract

RESUMOObjetivou-se, com o presente trabalho, verificar o efeito do extrato metanólico de Coffea racemosa Lour., espécie silvestre de cafeeiro portadora de resistência a uma das principais pragas da cultura cafeeira, o bicho-mineiro. Inicialmente, o extrato metanólico das folhas de C. racemosa foi pulverizado em mudas de cafeeiro Coffea arabica cv. Catuaí, em casa-de-vegetação, as quais foram expostas a adultos de L. coffeella para o teste de oviposição com chance de escolha. Observou-se que as plantas tratadas foram menos preferidas para oviposição. A seguir, realizou-se o teste de efeito ovicida, no qual mudas de C. arabica contendo ovos do bichomineiro foram pulverizadas com o mesmo extrato. Os experimentos foram conduzidos em delineamento inteiramente casualizado com cinco repetições. Verificou-se redução significativa na eclosão de larvas, e segundo análise por microscopia eletrônica de varredura, os ovos não viáveis apresentaram anomalias nas superfícies externas. Entretanto, os adultos provenientes de ovos tratados não foram afetados na percentagem de emergência, razão sexual e oviposição. Os resultados obtidos demonstram que C. racemosa apresenta-se como uma alternativa promissora ao controle do bicho-mineiro, necessitando, no entanto, de novos estudos para isolamento e identificação das substâncias bioativas. Termos para indexação:Leucoptera coffeella, inseticida botânico, café, produtos naturais. ABSTRACTThe objective of this study was to evaluate the effect of Coffea racemosa Lour. methanolic extract , a wild coffee specie that presents resistance against the coffee leaf-miner, a major pest of coffee crop. The methanol extract of C. racemosa leaves was sprayed on coffee seedlings, Coffea arabica cv. Catuaí, in greenhouse, which were exposed to adults of L. coffeella for oviposition in free choice test. Plants treated were less preferred for oviposition. An ovicidal assay was carried out by spraying the methanol extract on C. arabica seedlings containing L. coffeela eggs on their leaves. The experiments were conducted in a completely randomized design with five replicates. Larvae hatching out from treated eggs were significantly reduced by the extract and non viable eggs presented some anomalies on their external surfaces according to analyses by scanning electron microscopy. However, the adults derived from treated eggs did not have the percentage of emergence, sex ratio and oviposition affected by the treatment. The results show that C. racemosa presents as a promising alternative to control the coffee leaf-miner, being necessary new studies to isolate and caracterize the bioactive substances against this pest.

Agronomic, anatomic and physiological characterization of Coffea arabica L. genotypes on irrigated system in the Central Cerrado

“…In Coffea racemosa, a species known as resistant to the leaf miner (Alves et al, 2011;Ramiro et al, 2004) and drought (Medina Filho;Bordignon;Carvalho, 2008), compared to C. arabica (Ramiro et al, 2004) the adaxial and abaxial surfaces of epidermis were thicker. The thickness of the epidermis can vary depending on the environmental condition, particularly the conditions of strong solar radiation and water content in the soil (Baliza et al, 2012;Castanheira et al, 2016).…”

Alternative plant protection strategies for tomorrow's coffee

“…Alves et al (2011a, 2011b), Dantas et al (2020), De la Mora et al (2008), Gallardo‐Covas (1988, 1992),…”

“…A number of naturally derived bioprotectants have been evaluated for action against CLM over the last two decades (Alves et al, 2011a, 2011b; Mendonça et al, 2006; Rossi et al, 2010; Venzon et al, 2005). Neem seed extract (NeemAzal) was found to be an effective control against both CLM and the coffee red mite ( Oligonychus ilicis ) (Venzon et al, 2005).…”

Technological Inclusion in Small Coffee Plantations in the South of the State of Minas Gerais, Brazil

“…Increase in the monitoring of coffee plantations and investment in new technologies is a highly important item. The above activity enhances profit since it avoids losses caused by pests usually found in coffee plantations (Alves et al, 2011;Androcioli, 2010;Lopes et al, 2012).…”

“…Technological investment has been underscored as the great strengthener in the fastness of the production process and of increase in profits, mainly with regard to decrease in production costs (Amarasinghe et al, 2015;De Assis Silva;Lima et al, 2016;Perdoná et al, 2012;Ramalho et al, 2016;Rosa et al, 2010;Santinato et al, 2016;Xia et al, 2015). Further, the monitoring of pests which are abundant in the countryś coffee plantations also make possible fast control action in the culture (Alves et al, 2011;Lopes et al, 2012).…”