Potassium Silicate improves drought tolerance in Cotton by modulating growth, gas exchange and antioxidant activities

Abstract Cotton is a highly sensitive crop to drought stress. Consequently, it is crucial to devise strategies that optimize crop production in conditions of limited water availability. While potassium silicate has demonstrated effectiveness in mitigating drought stress in various crops, its specific impact on different cotton cultivars under drought conditions remains not fully clarified. This research aimed to assess the efficacy of six potassium silicate levels (ranging from 0, 100, 200, 300, 400 and 500 mg L-1) on four cotton cultivars (Zong main-113, Xin Nong-525, Xin lu Zhong-55, and Xin lu Zhong-66) under two field capacity levels (80% and 50% FC) in a sand culture. The application of foliar potassium silicate significantly improved photosynthetic efficiency, shoot biomass, root biomass, and leaf area under 50% FC. The most substantial reduction in H2O2, malondialdehyde levels, and electrolyte leakage was recorded with potassium silicate applied at a rate of 400 mg L-1. This concentration effectively mitigated reactive oxygen species accumulation, safeguarding plants against oxidative damage at 50% FC. Furthermore, potassium silicate contributed to maintaining water status, resulting in increased leaf water content and elevated water-soluble proteins in cotton plants. This research recommended that the foliar application of potassium silicate at a concentration of 400 mg L-1 significantly enhances cotton's resistance to drought, offering valuable insights for sustainable cotton cultivation in water-limited environments.