Caracterização nutricional do nim em plantios no Brasil

Abstract

RESUMONo Brasil são incipientes os estudos sobre os aspectos nutricionais do cultivo do nim. Propôs-se, neste trabalho, determinar os teores foliares de macronutrientes em plantios de nim estabelecidos em oito Estados do Brasil e correlacioná-los com os nutrientes disponíveis na camada de 0-20 cm de profundidade dos solos sob os plantios amostrados. De cada plantio foram coletadas folhas de nove árvores das partes média/superior e média/inferior da copa, as quais foram misturadas, formando duas amostras compostas denominadas folhas da copa média/superior (FCMS) e folhas da copa média/inferior (FCMI). Para análise de variância dos teores foliares de nutrientes utilizou-se o delineamento inteiramente casualizado, com decomposição total dos graus de liberdade visando ao efeito local de plantio, idade de plantio e posição na copa, sendo a comparação de médias realizada pelo Teste de Duncan (p ≤ 0,05). A amostragem foliar nas árvores de nim depende, quando feita na posição mediana subdividida em FCMS e FCMI, entre outros fatores, da mobilidade do nutriente e da condição de luminosidade do plantio. Os teores foliares de Ca apresentam indícios de ser o nim uma espécie calcícola. O nim é eficiente na absorção de N, P e Ca. O K do solo apresenta correlação positiva com o K das FCMI. Palavras-chave:Azadirachta indica A. Juss., macronutrientes da planta, relação solo-planta Nutritional characterization of neem plantations in Brazil ABSTRACT In Brazil, there are very few studies about nutritional status of neem. This study aimed to determine the contents of macronutrients in leaf in neem plantations established in different locations in eight states of Brazil, and perform correlations with the available nutrients in the respective soils under the sampled plantation. From each plantation the leaves were collected from nine trees, from the middle superior and middle inferior part of the crown. Each part of the crown of the nine trees were mixed, forming two composite samples and were nominated as leaves from the middle superior crown (FCMS), and middle inferior crown (FCMI). At the time of leaf sampling, the soil was collected in 0-20 cm depth. For variance analysis of the nutrient contents of leaf, a completely randomized design was used, applying total decomposition of the degrees of freedom for stand localization, stand age and crown position effect, being the mean comparisons performed by the Duncan test (p ≤ 0,05). Additional correlation and cluster analysis were applied integrating soil data. The leaf sampling of neem trees, when realized in the middle of the crown subdivided in FCMS and FCMI depends, among other factors, on the nutrient mobility and on the light conditions of the stand. The leaf contents of Ca show indications that the neem plant could be a calcicole plant, and efficient in N and P absorption. The soil K content is positively correlated with the K content of the FCMI position.

Pinnaspis strachani (Cooley) (Hemiptera: Diaspididae) infesting neem trees (Azadirachta indica A. Juss., Meliaceae) in Bahia, Brazil

“…Parts of the plant can be used as natural botanical insecticides and its wood is resistant and hard (RodRigueS et al 2017), indicating its use in large-scale production (moReiRa et al 2012). In Brazil, neem is grown in the Cerrado, Caatinga, Atlantic Forest, and Amazon regions (NeveS et al 2013) and is part of afforestation of several cities (LuNdgReN et al 2013;Soto et al 2014;daNtaS et al 2018). Although neem is used for insect control, several scale insects and other arthropods have been reported to damage this plant around the world (CaBi iNteRNatioNaL 1999;PeNteado et al 2011).…”

Do native plant species functionally similar to invasive species suffer more impacts from the invasion in seasonally dry tropical forests?

“…Some studies evaluated changes in natural communities in Brazil after biological invasion (Andrade et al 2009;Fabricante et al 2012), but there are many exotic species with an invasion history in country (I3N 2020) that need to be studied. One of them, Azadirachta indica A. Juss (Meliaceae), is native to the Asian region and introduced in Brazil in 1984, initially in the state of Paraná and later was disseminated to several states in different regions of the country (Neves & Carpanezzi 2008, 2009, has been widely used in afforestation (Edson-Chaves et al 2019;Silva et al 2019) due to its rapid growth and shady canopy (Neves et al 2013;Lima et al 2018;Almeida et al 2019), causing concern among scientists. This plant has characteristics that favor invasion, such as early reproduction under several environmental conditions and large seed production, which can be dispersed by birds, bats and land mammals over espécies plantadas isoladamente, M. caesalpiniifolia, C. pyramidale e L. ferrea foram funcionalmente mais próximas da exótica.…”