The importance of weeds as melliferous flora in central Chile

The use of native flora by Apis mellifera L. in Chile has been demonstrated in many studies; however, certain species that are viewed as weeds contribute extensively to the floral composition of honey. A total of 92 honey samples from the Libertador General Bernardo O’Higgins region in Chile were analyzed to determine which weeds are most important in honey production and which are most preferred by melliferous bees. Their relative contributions to the pollen fraction of each honey sample were also determined using melissopalynological tests in accordance with Chilean regulation (NCh2981.Of2005; Ministerio de Agricultura. 2006) to evaluate the botanical origins of the honey samples. Species considered weeds were classified according to their importance in Chilean crops, as proposed by Matthei (1995), based on the classification system by Holm (1979). These authors categorize weeds on a scale that ranges from “very serious”, if they potentially cause significant crop loss, to “occasionally present as weeds” if they are part of the national flora. A total of 19 weeds were identified at the species level from the pollen types found, and five weeds were identified at the genus level. The weeds were classified as contributing very frequently, frequently, rarely and occasionally to honey using the methodology described by Louveaux et al. (1970) for determining the frequency with which plant species contribute to honey based on the corresponding pollen types found in honey. Overall, 74% of the weeds used by Apis mellifera were European, and 53% of the weeds had perennial life cycles. The families that contributed the most to honey production were Fabaceae, Asteraceae and Brassicaceae . The importance of species viewed as weeds in the production of Chilean honey is discussed. Estudios en Chile han demostrado la utilizacion de flora nativa por Apis mellifera L. , sin embargo existen situaciones en que especies consideradas malezas tienen una alta participacion en la composicion floral de la miel. Para determinar que malezas son las mas importantes y preferidas por la abeja melifera, se analizaron 92 mieles provenientes de la Region del Libertador General Bernardo O’Higgins, a las cuales se les determino su participacion relativa en la fraccion polinica. Para la evaluacion del origen botanico se utilizo la Norma Chilena (NCh2981.Of2005) mediante analisis melisopalinologico. A las especies consideradas malezas se las clasifico segun la importancia que poseen en los cultivos chilenos, de acuerdo a lo propuesto por Matthei (1995) usando la clasificacion definida por Holm (1979). Estos autores categorizan las malezas desde muy seria, si tienen el potencial de causar perdidas significativas del cultivo; a malezas con presencia ocasional, si solo son parte de la flora del pais. Del total de morfos polinicos encontrados, se logro identificar 19 malezas a nivel de especie y cinco a nivel de genero, las que varian entre muy frecuente, frecuente, raro y esporadicos, de acuerdo a la metodologia para diagnosticar la frecuencia especifica en mieles descrita por Louveaux et al. (1970). Del total, el 74% de las malezas usadas por Apis mellifera fueron de origen europeo, y 53% corresponden a malezas con ciclo de vida perenne. Las familias mas importantes corresponden a Fabaceae, Asteraceae y Brassicaceae . Se discute la importancia de especies consideradas malezas en la produccion de miel chilena.