Zinc outperforms other foliar fertilisers in enhancing lentil yield and harvest index in semi-arid regions

Lentil yield in semi-arid regions is limited by heat, drought stress and nutrient deficiencies induced by high soil pH and water scarcity. In this study, we investigated the effect of foliar fertiliser treatments on lentil yield and yield components in a semi-arid region of South-East Anatolia, Türkiye. The control treatment and six foliar treatments were as follows: (i) Control: non-amended control, (ii) Zn: zinc sulphate, (iii) K: potassium sulphate, (iv) Zn + K (zinc sulphate + potassium sulphate), (v) Flo: Florea-UPL (containing boron and molybdenum), (vi) Mac: Macarena-UPL, an organomineral foliar fertiliser and (vii) Flo + Mac. Foliar fertilisers were applied at the first blooming stage of field-grown lentils. Total biomass yield was largely unaffected across treatments except in the K treatment. However, foliar Zn supply was the only treatment that significantly increased grain yield (55% higher), harvest index and total grain N uptake compared to the control, likely due to enhanced translocation of nitrogen-containing assimilates. SPAD values and total N analysis showed that stover N content depleted more rapidly in the Zn treatment than in other treatments during the grain-filling phase. The tested commercial products slightly increased SPAD values, biomass and grain yield. Among the treatments, Zn, as a foliar fertiliser, was the most cost-effective solution for improving grain yield in this region.