Salinity is a growing problem worldwide and techniques are needed to mitigate this problem. The experiment was conducted to examine if biochar could improve growth, physiological response, and DM yield of forage sorghum (Sorghum bicolor (L.) Moench) under saline conditions. Sorghum seedlings were transplanted in sandy loam soil (0-20 cm layer of a Typic Fluvaquents Entisols) treated with sodium chloride at rates of 0.26, 5.8, and 12.6 dS m^-1. The saline soil was treated with four biochar rates, 0%, 2.5%, 5%, and 10% (w/w). Plant height, fresh weight, photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were affected by the interaction between salinity and biochar. At the 12.6 dS m^-1 salinity rate, 5% biochar increased plant height, leaf area, fresh weight, DM yields, A, gs, and E by 20.1%, 16.5%, 26.2%, 27.4%, 14.5%, 31.1%, and 26.7%, respectively. At the 12.6 dS m^-1 salinity rate, 5% biochar decreased CAT, POD, and SOD by 56.8%, 44.8%, and 18.9%, respectively. Furthermore, among all biochar rates used in this investigation, the 5% rate had a better result for forage sorghum production. These findings demonstrated that the lowest biochar soil amendment application could alleviate the harmful impact of salinity; a high biochar application rate can have a negative influence.

The presence of phyto-hormones in plants at relatively low concentrations plays an indispensable role in regulating crop growth and yield. Salt stress is one of the major abiotic stresses limiting cotton production. It has been reported that exogenous phyto-hormones are involved in various plant defense systems against salt stress. Recently, different studies revealed the pivotal performance of hormones in regulating cotton growth and yield. However, a comprehensive understanding of these exogenous hormones, which regulate cotton growth and yield under salt stress, is lacking. In this review, we focused on new advances in elucidating the roles of exogenous hormones (gibberellin (GA) and salicylic acid (SA)) and their signaling and transduction pathways and the cross-talk between GA and SA in regulating crop growth and development under salt stress. In this review, we not only focused on the role of phyto-hormones but also identified the roles of GA and SA responsive genes to salt stress. Our aim is to provide a comprehensive review of the performance of GA and SA and their responsive genes under salt stress, assisting in the further elucidation of the mechanism that plant hormones use to regulate growth and yield under salt stress.

Nutrient management is an important challenge to agricultural sustainability. In this study, the effects of three nitrogen (N) fertilizer levels (N1 = 0, N2 =150, and N3 = 300 kg ha⁻¹) on growth, chlorophyll content, and antioxidant capacity of two grain sorghum cultivars were investigated in a two-year (2017 and 2018) field trial. The treatments were arranged in a randomized complete block design with three replicates. Nitrogen application (N2 and N3) improved plant growth and antioxidant enzymes activity; compared to the control N1, N increased germination by 18.7%, leaf length by 7.5%, leaf weight by 10.8%, specific leaf weight by 11.6%, and plant height by 2.5% in Siyong 3180 cultivar and increased leaf width by 12.8% and stem weight by 27.4% in CFSH30 cultivar. In 2017 and 2018, increasing nitrogen N2 and N3 enhanced superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities and leaf protein content in both cultivars. While in 2017, chlorophyll content decreased in the CFSH30 cultivar. Our study showed that increased nitrogen supply could improve morpho-physiological activities of sorghum, but N3 was relatively more effective for sorghum growth in Siyong 3180 cultivar compared to CFSH30 cultivar.