Performance of High-Tillering Hybrid Wheat under Climate Stress Conditions in Semi-Arid Environments

Wheat (Triticum aestivum L.) productivity in Pakistan remains constrained by climatic stress, weed pressure, suboptimal seed quality, and stagnating genetic gains. This study evaluated the performance of high-tillering wheat hybrids under climate-challenged conditions while simultaneously assessing weed flora composition, herbicide efficacy, and seed purification strategies in Sindh, Pakistan. Four experimental hybrids (H-101, H-104, H-110, and H-112) were compared with a commercial check (TJ-83) using a randomised complete block design across the rabi season. Key agronomic traits, including tillering capacity, yield components, grain yield, and harvest index, were recorded. Weed surveys identified dominant species and quantified weed pressure, while commonly used herbicides were evaluated for weed control efficiency and yield response. Seed purification was conducted across breeder nucleus, pre-basic, basic, and certified seed generations to assess genetic purity. Significant variation was observed among hybrids, with H-101 exhibiting superior tillering and grain yield compared with the check variety. Weed flora was dominated by Phalaris minor and Avena fatua, accounting for over 70% of total weed density. Herbicide application significantly reduced weed pressure, with clodinafop-propargyl showing the highest weed control efficiency; however, reliance on single modes of action raises concerns about resistance development. Seed purification improved genetic purity to 99.8% at the certified seed stage, meeting international standards. The findings demonstrate that hybrid wheat, when supported by integrated weed management and robust seed systems, can contribute substantially to closing yield gaps under climate stress.