Combined Application of Biostimulants and EDTA Improved Wheat Productivity under Cadmium Stress

Abstract

Wheat (Triticum aestivum L.) exhibits a greater capacity for cadmium (Cd) absorption compared to other cereal crops, leading to elevated daily Cd intake, and posing a significant threat to public health. For the mitigation of Cd stress in sustainable and environmentally friendly way, a pot study was designed by using exogenous application of various biostimulants, i.e., Nigella sativa and Ocimum sanctum extracts: 0%, 10%, and 20% in combination with the chelating agent ethylenediaminetetraacetic acid (EDTA) using 0 and 5 mg kg under various levels of Cd stress (i.e., 0, 5, 10, and 15 mg kg soil). Results revealed that Cd stress significantly reduced the seed emergence, growth, root, and allometric characters and yield-related parameters of wheat crops. The most observable reduction was documented in wheat plants exposed to a higher Cd concentration (15 mg kg), followed by the lower Cd level (control). The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress. The highest increase in seedling emergence (5.44%), leaf area (50.60%), number of tillers (31.02%), grain yield per plant (24.28%), biological yield (13.97%), and decrease in Cd levels in grains (40%) was noticed where 20% foliar application of N. sativa and 10% of O. sanctum biostimulants were done using 5 mg kg of soil-applied EDTA. This intervention demonstrated a notable reduction in Cd-induced negative effects, highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments. Moreover, it is an eco-friendly and approachable method at the field level able to ensure food safety.