Evaluación de extractos acuosos de hierba luisa y oregano sobre el crecimiento micelial moniliophthora roreri a nivel in vitro

Abstract

In Ecuador cocoa (Theobroma cacao) is one of the main products in the traditional Ecuadorian export. According to the National Institute of Statistics and Censuses (INEC), the cocoa sector contributes to the national economically active population with 5% (PEA) and 15% of the rural PEA, the cocoa sector contributes 5% of the economically active population . Around 3.3 million tons of cocoa beans are exported worldwide, which represents 15% in Latin America and the Caribbean. In Ecuador, small producers lead production by 95%, with Los Ríos, Guayas, Manabí, Esmeraldas and El Oro being the provinces with the highest cocoa production in the country, with an area of ​​500 thousand hectares. The main limiting disease in cocoa is Moniliasis caused by the fungus Moniliophthora roreri, its symptoms begin with circular yellow and brown oily spots, which can expand to cover the entire fruit and then spread to all the pods of the plantation. For the control of Moniliasis, different alternatives are applied, composed of chemical, biological and cultural control. Botanical extracts have the particularity of having secondary metabolites, which are chemical compounds formed by the plants themselves that act as a defense mechanism against predators and phytopathogens, therefore, they can be characterized by inhibiting the growth of phytopathogenic fungi. Based on the problem of not having an adequate management of diseases, the use of botanical extracts is proposed as an alternative in the control of Moniliasis, using plants that have anti-fungal characteristics such as Oregano (Origanum vulgare L.) and Lemongrass (Cymbopogon citratus). The treatments used in the research are detailed below: T1 (aqueous extract of Oregano at 10%); T2 (aqueous extract of Oregano at 20%); T3 (aqueous extract of Oregano at 30%); T4 (aqueous extract of Lemongrass at 10%); T5 (aqueous extract of Lemongrass at 20% ); T6 (aqueous extract of Lemongrass at 30%); T7 (aqueous extract of Oregano + Lemongrass at 10%); T8 (aqueous extract of Oregano + Lemongrass at 20%); T9 (aqueous extract of Oregano + Lemongrass at 30%); T10 (Absolute control), these treatments were applied according to their corresponding doses. For the elaboration of the treatments we use three Erlenmeyer flasks where we place the fresh material of the different plants, the dosage that was used in each Erlenmeyer flask was: 60gr of Oregano/180ml of distilled water; 60g of Lemongrass/180ml of distilled water and a combination of 30g of Oregano – 30g of Lemongrass/180ml of distilled water, the final weight/volume ratio was 1:3. Under controlled laboratory conditions, the treatments that presented the greatest inhibitory effect are T1 aqueous extract of Oregano at 10%; T2 aqueous extract of Oregano at 20%; T3 aqueous extract of Oregano at 30%, both are statistically equal and different from the rest of the treatments, which did not present any inhibitory effect in relation to the control, finally the use of botanical extracts is recommended as an alternative control in the management of fungal diseases .