Biological effectiveness of quillay (Quillaja saponaria) extracts for the control of yellow aphids (Melanaphis sacchari) in sorghum

The yellow sugarcane aphid (Melanaphis sacchari) is one of the most harmful pests for the cultivation of sorghum (Sorghum bicolor) and since 2013 has caused losses from 30 to 100% in the production of sorghum in Mexico. For its control only chemical products are used by recommended of the Cómite Estatal de Sanidad Vegetal del Estado de Morelos, no natural products are used. For this reason, the present study was proposed to define some extract of plants for the control of the M. sacchari in order to avoid environmental pollution and to improve the profitability of the crop. In one plot of sorghum with a high incidence of M. sacchari in Jantetelco, Morelos, three doses (2, 4 and 6 mL / L of water) of Quillaja saponaria extract, (0.2 mL / L of water) of Imidacloprid, (10 mL / L of water) of Calcium Polysulfide and treatment without application. The applications were made with a manual spray bag, with a capacity of 15 liters, previously calibrated and with a fan nozzle. A completely randomized block design with six treatments and four replicates was used. The experimental unit was formed by 5 rows of 5 m long and 0.70 m between rows, giving a total area of 17.5 m2 per experimental unit. The useful plot was of the three central grooves, leaving 0.5 m at each end of the groove. The total size of the experimental plot was 420 m2. The biological effectiveness during sampling, treatments with Quillaja sp saponaria in doses of 6, 4 and 2 mL / L of water, had a 100 % effectiveness and the effectiveness of Imidacloprid was also of 100 %. The treatments based on extracts of Quillaja saponaria on M. sacchari in the sorghum crop, showed 100 % of biological effectiveness from the first application and no phytotoxicity was observed in the experiment.Objective: To evaluate and define a plant extract for the control of the yellow aphid in order to prevent environmental contamination and improve crop profitability. Design/Methodology/Approach: In a sorghum plot —located in the municipality of Jantetelco, Morelos— with a high incidence of yellow aphids, three doses —2-, 4-, and 6-mL L-1 of water of Quillaja saponaria extract, 0.2-mL L-1 of water of Imidacloprid, and 10-mL L-1 of water of calcium polysulfide—, as well as an absolute control, were evaluated. The applications were carried out using a 15-L manual spray backpack, which had been previously calibrated and had a fan nozzle. A randomized block experimental design—with six treatments and four repetitions— was used. The experimental unit was made up of five 5-m long rows with 0.70 m between rows, resulting in a 17.5 m2 total area per experimental unit. The three central furrows were the useful plot, leaving 0.5 m at each end of the furrow. The total size of the experimental plot was 420 m2. Results: The biological effectiveness during the samplings was as follows: both the Quillaja saponaria (6-, 4- and 2-mL L-1 water doses) and Imidacloprid treatments had a 100% effectiveness. Study limitations/implications: This study was carried out in sorghum crops. Findings/conclusions: Treatments based on Quillaja saponaria extracts on M. sacchari in sorghum crops showed 100% biological effectiveness from the first application and no phytotoxicity was observed in any treatmen