Avaliação do efeito curativo e preventivo do óleo essencial do capim citronela no controle de Pyricularia grisea

Abstract

The rice blast is the most important disease of the rice, due to the damage that it causes in the productivity and grain quality. Aiming at the use of essential oils and plant extracts to control this disease. The objective of this study was to evaluate the curative and preventive effect of the extracts and essential oil of citronella grass (Cymbopogon nardus L.) to control rice blast. The evaluation of the curative effect was performed seven days after the spraying with the extracts of citronella grass. As for the evaluation of preventive effect, the plants were sprayed with the treatments and 24 hours after inoculated with 20 mL of the spore solution per tray. In the assessing of the curative effect, it was found that the application of fungicide and the diluted essential oil of citronella grass at a concentration of 2% plants showed no symptoms of blast in 50% of the repetitions. Regarding the evaluation of preventive effect, the plants showed no symptoms of the disease in concentrations of 1.5, 1.75 and 2% of the essential oil of citronella grass in 50% of the repetitions.

Citrus Essential Oils as an Alternative Method of Control of the Fungus Alternaria alternata (Fr.: Fr.) Keissler

“…Late IAC 855 willowleaf y = 0,0003x 2 -0,1349x + 2,2833 0,98 The curative effect of citronella EO on rice brusone (Pyricularia grisea) was observed to reduce disease incidence by up to 50% in replicates (46). Better results were also observed in the preventive effect of noni EO application, when compared to the curative in the control of anthracnose (C. gloeosporioides) in mango plants (47).…”

Soil Fertility and Essential Oil Production in Citronella Cultivation Irrigated With Dairy Cattle Wastewater (Dcw)

“…It should also be highlighted that one of the markets that has become viable for small producers is the medicinal or aromatic plants production, particularly citronella grass (Cymbopogon nardus (L.) Rendle), due to its rusticity and its ability to adapt to different types of soils and climates (Sivashanmugam et al, 2009;Faria et al, 2018;Zhang et al, 2019), besides presenting economic value related to the essential oil extracted from it (Perini et al, 2011). Thus, the interest and development of studies about it have been highlighted (Castro et al, 2007;.…”

“…These substances act as a chemical defense of the plant against predators (Castro et al, 2007). Citronellal is used as a basic material for the synthesis of important chemical compounds (Furlan et al, 2010;Perini et al, 2011). Essential oils have a complex chemical composition, especially the presence of terpenes and phenylpropanoids.…”

Efeito de extratos vegetais na inibição do crescimento micelial de Pyricularia grisea

“…De acordo com Marques et al (2004), a utilização de fungicidas de origem vegetal poderá constituir um método alternativo e promissor para o controle de pragas, pois além de serem de fácil obtenção e baixo custo, minimizam os problemas de toxicidade apresentados pelos produtos químicos sintéticos. Diversos trabalhos com óleos essenciais têm indicado o seu potencial no controle de bactérias (Silva et al, 2010;Demuner et al, 2011;Nascimento et al, 2011) e de fungos fitopatogênicos, considerando que a inibição do desenvolvimento de fungos pode ser tanto pela ação direta, inibindo o crescimento micelial e a germinação de esporos, quanto pela indução de resistência a diversos patógenos (Donlaporn e Suntornsuk, 2010; Deus et al, 2011;Perini et al, 2011;Garcia et al, 2012;Passos et al, 2012;Silva et al, 2008). Os extratos de plantas medicinais contêm metabólitos secundários que são considerados produtos finais do metabolismo das plantas e têm importância ecológica para as plantas que os sintetizam.…”