Evaluating the impact of silicon soil amendments on insect pests of soybean

Redbanded stinkbugs (RBSB) and soybean loopers (SL) are economically important insect pests of soybeans in Louisiana. These pests can significantly reduce yields and the quality of seeds. While synthetic insecticides provide efficient and rapid control of pests, they can pose risks to humans and the environment. Amending soils with silicon has been shown to enhance plant tolerance to biotic and abiotic stresses. In fact, previous studies reported that silicon soil amendment can reduce feeding injury to plants and disrupt feeding efficiency by insect pests. This study was conducted to evaluate the effects of silicon soil amendment on redbanded stinkbug and soybean looper infestations in soybean plants under field conditions. Field experiments were conducted at Dean Lee Research Station (Alexandria), Macon ridge research station (Winnsboro), and Texas A&M University Agricultural Research and Extension Center (Beaumont Texas) in 2024. Field plots were arranged following a randomized block design with four blocks and one replicate per block. Treatments include factorial combinations of silicon amendment, (Wollastonite Vansil W-19 used as silicon source), RBSB, and SL infestations. Natural infestations of RBSB and SL were monitored throughout the season. Results showed no significant difference in plant establishment in silicon treated and non-treated plots. However, significant result was shown in plant dry weight of silicon treated plots collected at vegetative stage. RBSB infested the fields in 3 locations but the effect of silicon on SL was not evaluated due to low population for the duration of the trial.