Efficiency of essential oils to control Colletotrichum theobromicola in vitro

Essential oils promote the inhibitory control of several fungi, including those within the genus Colletotrichum, the causal agent of Anthracnose, a disease which may occur at any stage of development in various crops, reducing up to 70% of crop production in some cases. Thus, the use of alternative products constitutes an important strategy for the integrated management, promoting less persistent molecules in the environment and lower toxicity rates, providing health benefits to producers and consumers of agricultural products. In this context, the present study evaluated the in vitro fungitoxic effect of essential oils from Java citronella (Cymbopogon winterianus), clove (Syzygium aromaticum), eucalyptus (Eucalyptus globulus) and rose pepper (Schinus terebinthifolius) on the mycelial growth of Colletotrichum theobromicola. The experiment was performed under completely randomized design, in a 4x5 factorial scheme (4 essential oils x 5 concentrations), with five replications, and the experimental unit consisting of a Petri dish. The treatments were generated by combining the concentrations (0, 5, 10, 15, 25 and 50 μL mL-1) of essential oils (citronella, clove, eucalyptus and rose pepper). The plates were inoculated with the pathogen C. theobromicola and incubated for seven days at 25 ± 2 °C. To verify the difference between treatments, the percentage of mycelial growth inhibition (PGI) was estimated. The mycelial growth of C. theobromicola was significantly reduced with increasing concentrations of essential oils. At a concentration of 50 μL mL-1, the essential oil from S. terebinthifolius showed the best result inhibiting 54.57% of mycelial growth, followed by the oil from S. aromaticum (49.26%), C. winterianus (23.70%) and E. globulus (17.90%). All the studied oils showed antifungal activity

Essential oil of clove (Syzygium aromaticum) to control Sclerotium rolfsii in vitro

Essential oils can inhibit growth of several phytopathogenic fungi of agricultural concern, such as Sclerotium spp. which causes root and collar rots, hampering the absorption of water and nutrients. Natural oils have short persistence in the environment and low toxicity, comprising compounds safer than conventional agrochemicals. Within the context of integrated management of diseases, essential oils may benefit the health of farmers, consumers and the environment. This study evaluated the in vitro inhibitory effect of clove (Syzygium aromaticum) essential oil on the mycelial growth of Sclerotium rolfsii. The experimental design was completely randomized, with 7 treatments (5 oil concentrations, 1 negative control, and 1 positive control) and five replications, with the experimental unit constituted by a Petri dish. The treatments consisted of different oil concentrations (0.0125; 0.025; 0.05; 0.1 and 0.2%) of clove essential oil, a negative control (0.0%) and a positive control, fungicide Tiram (1 mL L-1). The essential oil and the fungicide Tiram were merged into the synthetic Potato-Dextrose-Agar (PDA) culture medium. The plates were inoculated with the pathogen S. rolfsii and incubated for seven days at 25 ± 2 °C. We compared the treatments through the percentage of mycelial growth inhibition (PIC) and the mycelial growth velocity index (IVCM). Increasing oil concentration significantly reduced the mycelial growth of S. rolfsii and paralyzed mycelial growth at 0.1% concentration. The effect of clove essential oil was similar to the commercial fungicide

Efficiency of essential oils to control Colletotrichum theobromicola in vitro

Essential oils promote the inhibitory control of several fungi, including those within the genus Colletotrichum, the causal agent of Anthracnose, a disease which may occur at any stage of development in various crops, reducing up to 70% of crop production in some cases. Thus, the use of alternative products constitutes an important strategy for the integrated management, promoting less persistent molecules in the environment and lower toxicity rates, providing health benefits to producers and consumers of agricultural products. In this context, the present study evaluated the in vitro fungitoxic effect of essential oils from Java citronella (Cymbopogon winterianus), clove (Syzygium aromaticum), eucalyptus (Eucalyptus globulus) and rose pepper (Schinus terebinthifolius) on the mycelial growth of Colletotrichum theobromicola. The experiment was performed under completely randomized design, in a 4x5 factorial scheme (4 essential oils x 5 concentrations), with five replications, and the experimental unit consisting of a Petri dish. The treatments were generated by combining the concentrations (0, 5, 10, 15, 25 and 50 μL mL-1) of essential oils (citronella, clove, eucalyptus and rose pepper). The plates were inoculated with the pathogen C. theobromicola and incubated for seven days at 25 ± 2 °C. To verify the difference between treatments, the percentage of mycelial growth inhibition (PGI) was estimated. The mycelial growth of C. theobromicola was significantly reduced with increasing concentrations of essential oils. At a concentration of 50 μL mL-1, the essential oil from S. terebinthifolius showed the best result inhibiting 54.57% of mycelial growth, followed by the oil from S. aromaticum (49.26%), C. winterianus (23.70%) and E. globulus (17.90%). All the studied oils showed antifungal activity