Determination of Silicon Accumulation in Non-Bt Cotton (Gossypium hirsutum) Plants and Its Impact on Fecundity and Biology of Whitefly (Bemisia tabaci) under Controlled Conditions

Considering the resistance development-potential of whitefly (Bemisia tabaci) against control tactics with limited action mechanisms, the present study investigated the accumulation of two different silicon (Si) sources (SiO2 and K2SiO3) in cotton plants. The tested dose rates (0, 200, and 400 mg/L) of both Si sources were applied directly to the soil or through foliar application on cotton leaves. Moreover, a laboratory bioassay was also conducted to evaluate the performance of applied Si sources against the oviposition preference and biology of B. tabaci. A significantly higher Si accumulation, reduction in oviposition preference, and prolonged developmental period of all nymphs and total life cycle of B. tabaci was observed in the case of foliar-applied silicon. Similarly, among Si sources, a significant decline in the number of oviposited eggs and delay in the developmental period of B. tabaci was observed in the case of SiO2, followed by K2SiO3. Moreover, cotton plants subjected to SiO2 treatments possessed higher Si contents in their leaves than K2SiO3 treated plants. The results further revealed that both Si sources showed promising results at their higher concentrations regarding the tested parameters of Si accumulation, fecundity, and developmental period of B. tabaci. Our results strongly suggest that among emerging pest control strategies in cotton plants lies the use of foliar application of Si, which can also be incorporated in different integrated pest management programs due to its safety for humans and beneficial insect fauna.