04878naa a2200289 a 450000100080000000500110000800800410001902200140006002400360007410000190011024501710012926000090030030000090030952039880031865000140430665000130432065000220433365000230435565000190437865000150439770000220441270000200443470000250445470000230447970000230450277300630452521396682022-02-04       2021    bl uuuu     u00u1 u    #d  a0254-62997 a10.1016/j.sajb.2021.01.0142DOI1 aMARTINS, S. A.  aAllelopathic potential and phytochemical screening of Piper divaricatum extracts on germination and growth of indicator plant (Lactuca sativa).h[electronic resource]  c2021  a4 p.  aBrazil is an outstanding agricultural exponent in the world market economy of food, fiber, and derivatives. Agricultural research has significantly contributed to technology increment, ensuring competitiveness and high production, especially for significant agricultural commodities. However, producers often encounter climatic difficulties that cause problems of an abiotic or biotic nature. The occurrence of pests (pathogens, insects, and weeds) is the most adverse factor for production, increasing their costs by acquiring agricultural inputs (Albuquerque et al., 2011; Shah et al., 2016). Weeds are considered the most harmful pests to commercial crops due to the broad diversification and competitive power. The usual control is through chemical pesticides, which, despite its efficiency, is more expensive and leads to severe losses to human health and the environment. The search for alternative forms of weed control has been the subject of studies focused on cheaper, more selfsustaining and agroecological management of crops (Albuquerque et al., 2011). The allelopathy fits in this segment because consists in prospection of plant metabolites with herbicidal action, with potential to inhibit or control the growth of other neighboring plants (Albuquerque et al., 2011; Shah et al., 2016). Literature displays several reports on biochemical processes involved in synthesis of allelochemicals and responses of target plants. Among the most reported classes are terpenoids, coumarins, flavonoids, catechins, quinones, and tannins, found in several plant species, in varied concentrations. Once released into the soil by the donor plant, allelochemicals enter a complex plant-soil system in which diverse factors affect their availability, and consequently their effective influence on target plants (Kruse et al., 2000; Li et al., 2010; Nebo et al., 2014; Araniti et al., 2015; Gulzar et al., 2016). Several vegetal species with occurrence in Amazon present with broad agricultural and pharmaceutical potential, such as Piperaceae family, currently composed of six genera, including approximately 3,495 species (Roskiv et al., 2017). The genus Piper has been widely reported in literature due to secondary metabolites found in extract and essential oil, with broad antimicrobial, antifungal and allelopathic properties (Cunico et al., 2004; Lustosa et al., 2007; Silva and Bastos, 2007; Zacaroni et al., 2009; Bernuci et al., 2016; Silva et al., 2017). P. hispidinervum C. DC., P. aduncum L., P. nigrum L., P. arboreum Aubl., P. marginatum Jack., P. reticulatum L., and P. divaricatum G. Meyer are more reported. The most hold several kinds of compounds with biocidal properties, such as terpenes, phenylpropanoids, aldehydes, ketones, lignans and neolignans (Parmar et al., 1997; Lustosa et al., 2007; Zacaroni et al., 2009). P. divaricatum is a shrub known in Brazil as pau-de-angola or jaborandi-manso. The essential oil is rich in phenylpropanoids such as methyl eugenol, and eugenol presents mainly in the leaves, with high potential to pesticide industry due to activity as formicide on Solenopsis saevissima, and fungicide on Cladosporium cladosporioides, C. sphareospermum and Fusarium solani f. sp. piperis (Silva et al., 2010; Silva et al., 2014). Prospecting studies of plant species with pesticide potential, followed by the chemical identification of their compounds, are relevant especially in countries with vast biodiversity, such as Brazil. Preliminary studies of allelopathic potential of P. divaricatum aqueous extract showed high inhibition in vivo on emergence and growth of lettuce (Lactuca sativa), and weeds Cenchrus echinatus (Burger), Bidens pilosa (hair beggarticks) and Digitaria insularis (sourgrass) at 7.5% (Rafalski, 2017; Rafalski et al., 2016). Based on these results, we are reporting the prospecting of new allelopathic agents found in fractions of aqueous and other organic extracts of P. divaricatum, using lettuce as indicator plant.  aAlkaloids  aCoumarin  aOrganic compounds  aComposto Orgânico  aLactuca Sativa  aPiperaceae1 aSANTOS, R. C. dos1 aRAMOS, A. de R.1 aFIGUEIREDO, P. L. B.1 aSILVA, C. R. C. da1 aSILVA, J. K. R. da  tSouth African Journal of Botanygv. 138, p. 495-499, 2021.