Silicon compounds promotes physiological response of avocado 'Hass’ and affect the development of pests

Abstract

The use of silicon (Si) can minimize the adverse effects of abiotic stresses, increase resistance against arthropod pests, and promote growth in fruit crops. Considering the beneficial effects of Si reported in various crops and the limited information on its effect on avocado, this study investigated the effects of the application of two sources of Si (acidic and alkaline) on the physiology, growth, and population dynamics of arthropod pests of 'Hass’ avocado plants. Three experiments were carried out at three different plant development stages: seedlings (Fresno, Tolima), young (Bituima, Cundinamarca), and adult trees (El Tablazo, Tolima). The treatments were as follows:1) plants without Si application (control), 2) plants with foliar application of acidic Si, 3) plants with foliar application of basic Si, and 4) plants with foliar treatment of acidic and basic Si and pyrethrins. Foliar applications of Si caused less accumulation of adult arthropod pests such as Heliothrips haemorrhoidalis, Monalonion velezangeli, Polyphagotarsonemus latus, Bombacoccus aguacatae, Paraleyrodes sp., and Oligonychus yothersi compared to the control treatment. Foliar applications of Si (both sources) also increased plant height and shoot length. Si had a positive effect on leaf stomatal conductance, chlorophyll content, and plant hydraulic conductivity at the end of the three experiments. The results obtained allow us to conclude that the use of Si can be considered a complementary tool in the management of some arthropod pests in avocados. In addition, Si may help in the management of avocado crops by improving the physiological responses of plants at different developmental stages.