Atividade antagonista do óleo essencial de Lippia alba (Mill.) N. E. Brown (Verbenaceae) sobre Meloidogyne incognita (Kofoid & White) Chitwood

Abstract

RESUMO: O controle de fitonematóides é uma tarefa difícil. A alta infestação de nematoides no solo obriga os produtores a usarem doses mais elevadas de nematicidas, ou ainda, a aumentarem a freqüência das aplicações, geralmente no solo, ocasionando maior potencial de dano ao homem e ao ambiente. Além disso, nematicidas convencionais vêm sofrendo grandes restrições de uso em muitos países. Desse modo, a busca de novas medidas de controle de fitonematóides é uma prioridade da agricultura sustentável. Desta forma, objetivou-se estudar o efeito de óleos essenciais de Lippia Alba, na mortalidade de juvenis pré-parasitas do segundo estádio de Meloidogyne incognita. O ensaio foi montado em delineamento inteiramente casualizado, com 4 repetições, em esquema fatorial 3×4 (3 quimiotipos x 4 concentrações) empregando-se três diferentes quimiotipos de L. Alba (I, II, III) nas concentrações de 0, 100, 500 e 1000 ppm, coletados em diferentes horas do dia (7, 9, 13, 16 e 19h ABSTRACT: Antagonist activity of the essential oil Lippia alba (Mill.) N. E. Brown (Verbenaceae) on Meloidogyne incognita (Kofoid & White) Chitwood. The control of nematodes is difficult. The high infestation of nematodes in the soil requires the producers use higher doses of nematicides, increasing the frequency of applications, usually in soil, causing negative effects to humans and the environment. Furthermore, conventional nematicides have suffered great use restrictions in many countries. Thus, the search for new measures to control nematodes is a priority of sustainable agriculture. Thus, the objective of this study was available the effect of essential oils from Lippia Alba against Meloidogyne incognita. The experiment was conducted in a completely randomized design with four replications in a factorial 3x4 (3 chemotypes and 4 concentrations) using three different chemotypes of L. Alba (I, II, III) at concentrations of 0, 100, 500 and 1000 ppm, collected in different times of day (7 AM, 9 AM, 1 PM, 4 PM e 7 PM). The data collected (% mortality) were subjected to analysis of variance and mean values were compared using the Tukey test. It was able to conclude that L. alba contains in its essential oil, compounds with significant effects on mortality of M. incognita. Thus, it is important to note that the greatest nematicide effect of essential oil of L. alba suggests the possibility of its use to control M. incognita.

Plant Volatiles Reduce the Viability of the Root-Knot NematodeMeloidogyne incognitaEither Directly or When Retained in Water

“…(Ntalli et al 2011;Silva et al 2013). Compounds such as 2,3-butanediol, sabinene, eucalyptol, limonene, and a-thujene found in sunflower seed emission were also reported in other volatilomes with activity against M. incognita (Barros et al 2014b;Gonçalves et al 2016;Silva et al 2013) but were not retained in the water.…”

Nematicidal Effects of Volatile Organic Compounds from Microorganisms and Plants on Plant-Parasitic Nematodes

“…VOCs produced by sunflower (Helianthus annuus) seeds cause high mortality in M. incognita [43]. VOCs found in the plant, such as 2,3-butanediol, sabinene, eucalyptol, limonene, and α-thujene, have also been reported to be active against M. incognita in other studies [53,73,74]. The essential oil of Artemisia nilagirica has strong nematicidal activity against M. incognita [44].…”

Assessment of the Tephrosia toxicaria essential oil on hatching and mortality of eggs and second-stage juvenile (J2) root-knot nematode (Meloidogyne enterolobii and M. javanica)

“…This is responsible for the inhibitory activity of hatching and mortality of M. incognita juveniles. Gonçalves et al (2016) analyzed the activity of the Lippia alba (Verbenaceae) essential oil on Meloidogyne sp., they verified that this oil contains compounds with significant effects on the mortality of juveniles of second stage of M. incognita. The three L. alba essential oil chemotypes show a similar effect at the concentration of 1,000 ppm, causing mortality above 99% of M. incognita juveniles (J 2 ).…”

“…There are many studies that demonstrate the efficiency of essential oils such as the following: Eucalyptus camaldulensis, E. saligma and E. urophylla on mortality and hatching of Meloidogyne exigua J 2 juveniles , the essential oil of Eucaliptus sp. on J 2 M. incognita (Ibrahim et al, 2006), the effect of the essential oils of Lippia sidoides, Ocimum gratissimum, Cymbopogon winterianus, Cymbopogon citratus, Lippia alba and Eucalyptus terenticornis on the hatch of the second stage juveniles (J 2 ) of M. incognita race 2 (Moreira et al, 2009), the essential oil of Kadsura heteroclite against M. incognita (Li et al, 2011), the essential oil of L. alba in the control of M. incognita race 1 (Marino et al, 2012), the essential oil of Vigna radiata in the control of gall nematodes, Meloidogyne sp., (Wani and Bhat, 2012), Myrtus communis essential oil on the mortality of J 2 of M. incognita (Ardakani et al, 2013), the effect of the essential oil of Rosmarinus officinalis in the control of the M. javanica (Mattei et al, 2014), the effect of the essential oil of L. alba (Verbenaceae) on hatching and mortality of juveniles of M. incognita (Gonçalves et al, 2016), the rhizome essential oil Alpinia galanga on hatching and mortality of J 2 of M. hapla (Nematoda: Tylenchida) (Jeon et al, 2016). It has been observed that the constituent compounds of the essential oils can act directly, interfering in the hatching and mortality of the nematodes in the soil (Bosenbecker, 2006), or, if they are absorbed by the plants, they may modify the composition the root exudates, interfering in the location of the roots by the nematodes, making them less attractive to the pathogen.…”