Impacts of Epihomobrassinolide and Thiamethoxam·Flutolanil·Azoxystrobin on the Continuous Cropping Stress of Pinellia ternata

Abstract

Continuous cropping (CC) stress severely limits the growth and industrial development of Pinellia ternata. Epihomobrassinolide (EBR) is a natural product that widely participates in many the physiological activities of many plants. Thiamethoxam·flutolanil·azoxystrobin (TFA) has been registered as a seed coating agent in crop production. In this work, the effects of seeds soaked with EBR, seeds coated with TFA, and their co-application on the plant growth, electrophysiological information (as physiological activities related to plant electrical signals), leaf photosynthesis, plant resistance, bulb quality, and yield of CC P. ternata were evaluated. The aim of this work is to excogitate a practicable agronomic measure for ameliorating the growth of CC P. ternata. The results show that soaking the seeds with EBR or coating the seeds with TFA could effectively enhance the plant height, leaf area, and stem diameter of CC P. ternata, promote its emergence seedling ratio, and decrease its inverted seedling ratio, and their associated application was found to be more efficient. Additionally, their associated application effectively enhanced the intrinsic capacitance (IC), intracellular water metabolism, nutrient transport, and metabolic activity and decreased the intrinsic resistance (IR), impedance (IZ), capacitive reactance (IXc), and inductive reactance (IXL). Meanwhile, their associated application could reliably enhance the photosynthetic capacity and stress resistance, and effectively improve the bulb quality and yield. This study emphasizes that the associated application of seeds soaked with a 0.004% aqueous EBR solution diluted 1000 times and seeds coated with a 24% TFA flowable concentrate at 1.6 mL kg−1 seed can be used as a novel and practicable technology for alleviating the CC stress of P. ternata and ameliorating its growth, electrophysiological information, resistance, quality, and yield.