Occurrence of weed species in Jatropha curcas intercropping systems

Abstract

-This study aimed to evaluate the level of infestation by weed species in a consolidated Jatropha plantation, as a function of the plant species grown in interrows. The experiment was installed in 2006 at the district of Itahum, city of Dourados, state of Mato Grosso do Sul, Brazil, made possible through a partnership between Embrapa Western Agriculture and Paraiso Farm. Treatments consisted of (1) Jatropha in monocrop, with no plant at the interrrows; or the following plants cultivaded at the interrows of Jatropha: (2) Stylosanthes spp.; (3) Brachiaria ruziziensis; (4) Brachiaria ruziziensis + Stylosanthess pp.; (5) Brachiaria humidicola; (6) Panicum maximum cv. massai; (7) Cajanus cajan cv. anão; (8) Crotalaria spectabilis; (9) Crop rotation system 1 -(maize second crop -Crambe abyssinica -soybeanpeanut); and (10) Crop rotation system 2 -(cowpea -radish -maize -cowpea) conducted for two years. Phytosociological characterization of weed species was accomplished in 2011 based on the Ecological Approach. Estimations of relative abundance, frequency, dominance and Importance Value Index were obtained. Areas were also characterized by the diversity coefficients of Simpson and modified Shannon-Weiner, and then grouped by cluster analysis. Areas with low soil coverage resulted in higher infestation levels; crop rotation in the interrows of Jatropha produced a significant reduction in weed infestation, but the lowest infestation levels were observed when grasses were grown intercropped with Jatropha. Lower diversity coefficients were associated with occurrence of the most troublesome weed species. In the first years after planting Jatropha, species of Brachiaria or a crop rotation involving species with high mulching ability and whose biomass exhibit a high C:N ratio, should be established in the interrows to avoid problems with weeds infestation.Keywords: Jatropha crop, infestation, phytosociology. Palavras-chave: pinhão-manso, infestação, fitossociologia. RESUMO: Objetivou-se com este estudo avaliar o nível de infestação por plantas daninhas em uma plantação consolidada de pinhão-manso em função da espécie cultivada nas entrelinhas da cultura. O experimento foi instalado em 2006 no distrito de Itahum, cidade de Dourados, Estado de Mato Grosso do Sul, tendo sido viabilizado por uma parceria entre a Fazenda Paraíso e a Embrapa Agropecuária Oeste. Os tratamentos consistiram do cultivo solteiro (1) ou das seguintes espécies cultivadas nas entrelinhas da cultura: (2) Stylosanthes spp.; (3) Brachiaria ruziziensis; (4)Brachiaria

Weed community composition in different agro-systems

“…Similarly, changes in the composition of weed communities were also observed in different agricultural crops, such as sugarcane (Kuva et al, 2007;Soares et al, 2011), pastures (Ferreira et al, 2014), bean (Tavares et al, 2013), cover crops (Lima et al, 2014;Lamego et al, 2015), manioc (Cardoso et al, 2013;Soares et al, 2015), corn (Correa et al, 2011), corn intercropped with legumes (Oliveira et al, 2014) and corn intercropped with forage (Batista et al, 2014;Concenço et al, 2015), millet (Teodoro et al, 2015), lettuce (Ferreira et al, 2013), Jatropha curcas (Concenço et al, 2014) and coffee under organic management (Maciel et al, 2010a;Partelli et al, 2010).…”

<i>Jatropha Curcas</i> as Marginal Land Development Crop in the Sultanate of Oman for Producing Biodiesel, Biogas, Biobriquettes, Animal Feed, and Organic Fertilizer

“…In terms of weed control, a dedicated study (Concenço et al, 2014) on this topic reported that areas with low soil coverage showed relatively high levels of weed infestation when crops are intercropped with Jatropha. It also found that crop rotation in the interrows of Jatropha was accompanied by a remarkable decrease in weed infestation.…”

Weed Species Dominance and Abundance in Tea (&lt;i&gt;Camellia sinensis&lt;/i&gt; L.) Plantation of Southwest Ethiopia

“…Weeds are the major problem of concern for the low productivity and economic losses to the producers. They are unwanted plants that compete with the crop plants for nutrients, water, space and light [1], and this competitive ability of weeds depends on various unrelated factors such as growth form of weeds, their density and time of weed emergence in relation to crop [2].…”

“…Unlike occurrence of other pests, which may be random and irregular, weeds can considerably decline yields without understandable signs of damage in crop production [5]. They harmfully affect crop growth and yield by competing with crops for nutrients, sunlight, space, and water; producing allelopathic interaction with crops, being parasitic on to crop plants and sheltering detrimental insect pests and plant pathogens [6,1,7]. Weed can cause 50-70% loss of tea productivity if its growth not limited [3].…”