The study tested different sources and levels of sulphur on mustard plants to see how it affected their growth and yield. They found that using ammonium sulphate as a source of sulphur led to the highest yield of seeds and plant material. Additionally, applying 60 kg of sulphur per hectare resulted in the best overall yield, closely followed by 40 kg per hectare. This suggests that the type and amount of sulphur used can significantly impact mustard crop production.