One of the solutions to the global warming risk and other climate issues is to concentrate on research and development of utilizing biomass as a fossil fuel alternative. The current estimate of cotton residue waste in the world is about 50 million tons. This massive volume of biomass waste should be turned into clean energy to avert burning the stalks in open fields after cotton harvesting. Therefore, harmful emissions such as CO₂ will be reduced. This study aims to investigate the published literature to comprehend the bioenergy production from the thermal treatment of cotton stalks, including combustion, pyrolysis, carbonization, torrefaction, liquefaction, and gasification. Furthermore, the future outlook, utilization, and prospective challenges of agricultural biomass for biofuel production are discussed. According to the literature, biochar and bio-oil derived from cotton stalks have high heating values of about 27.5 and 37.2 MJ·kg^-1, respectively. These values are double those of cotton stalk raw materials, which make it a good candidate for bioenergy production. This article offers valuable insight into cotton stalk utilization via thermochemical treatment and provides a solid reference for researchers, policymakers, and other stakeholders in this field.

Crop chemical regulation using plant growth regulators (PGRs) represents a key strategy for achieving high-efficiency cotton production in China. This review synthesizes four decades of research on mepiquat chloride (MC), an inhibitory PGR pivotal to optimizing cotton growth architecture, stress resilience, and yield-quality parameters. We detail MC's stage-specific roles—from root development and flowering acceleration to canopy optimization and assimilate partitioning—and its mechanistic interactions with hormones (e.g., gibberellin suppression, cytokinin enhancement) under biotic/abiotic stresses. Furthermore, we conceptualize MC deployment into three evolutionary tiers: (1) symptom-guided remedial application, (2) systemic growth-stage programming, and (3) integrated management with agronomic practices. These paradigms, supported by field validation across China's cotton belts, offer a roadmap for precision regulation. Future advancements in nano-formulations, digital agriculture, and PGR synergism are discussed to unlock next-generation yield frontiers.