Silicon application as an auxiliary method to control diamondback moth in cabbage plants

ABSTRACT Integrated pest management (IPM) strategies are among the factors promoting plant resistance to pests, and silicon application may increase this resistance. Thus, the aim of this research was to evaluate the control of diamondback moth (DBM), Plutella xylostella (Lepidoptera, Plutellidae) through foliar application of silicon in cabbage crops. The experiment was conducted in the vegetable producing area of Água Limpa Farm, Universidade de Brasília, Distrito Federal, Brasil. The experimental design was of randomized blocks with nine treatments and four replicates, totaling 36 plots. The applied treatments consisted of Agrosilicon® (10.5% Si) (T1), Sifol® (12% Si) (T2), deltamethrin 25 g L-1 (Decis® 25 EC) (T3), Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T4), Agrosilicon® + deltamethrin 25 g L-1(Decis® 25 EC) (T5), Agrosilicon® + Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T6), Sifol® + deltamethrin 25 g L-1 (Decis® 25 EC) (T7), Sifol® + Bacillus thuringiensis, 33.60 g L-1 (Dipel® SC) (T8) and control (T9). Agrosilicon® and Sifol® were applied weekly and the products deltamethrin and Bacillus thuringiensis were applied according to the damage level established for DBM in cabbage crops. Foliar application of silicon, alone or in combination with chemical and biological insecticides - T2, T7 and T8, were the best strategy to control DBM in cabbage crops, resulting in the lowest number of caterpillars per plant, lowest leaf damages and best aesthetic value of plants. Silicon foliar application can be considered as an auxiliary method of DBM management in cabbage crops, followed by the doses recommended by the manufacturers.