Physiological Growth Improvement of Maize (Zea mays L.) through Foliar Fertilisation under Irrigated Conditions

Rapid population growth necessitates increased food production, despite various crop stresses like drought and soil infertility hindering plant growth, development and yield. Maize is widely recognized as a crucial global cereal food crop. Precision practices, such as foliar fertilisation and irrigation, help mitigate crop stress. This study assessed the impact of foliar fertilisation on the physiological growth of three maize hybrids (FAO 320, FAO 400 and FAO 430) under irrigated conditions at the Látókép Crop Production Experimental Site, University of Debrecen, Hungary, in 2024. Foliar fertiliser treatments included nitrogen (10 g/L), zinc (8 g/L), K₂O (8.5 g/L), P₂O₅ (0.83 g/L), and sulfur (8.93 g/L). Surface drip irrigation lines were placed in each row close to the plants, delivering water at a rate of 3 liters per hour, managed by the HydraWise app and regulated by data from the nearby meteorological station. The key physiological growth parameters studied included NDVI (Normalized Difference Vegetation Index), Leaf Area Index (LAI) and SPAD values. Data were collected at the V12, VT, R4 and R6 growth stages. The impact of foliar fertilisation was analysed using a T-test to compare treatment effects. The treatment effects showed no significant difference on NDVI, LAI nor SPAD. FAO 320 had the lowest values for all the parameters studied compared to other hybrids. Hybrid FAO 400 recorded the highest NDVI and SPAD values (0.78 and 56.9). LAI had a significant difference (P<0.001) between the treatments and control; however, FAO 430 had highest overall LAI value (5.2) compared to other treatments. The control recorded better SPAD values than the treatments (all hybrids), although the difference was not significant. Hybrid FAO 400 had the best overall physiological growth performance due to foliar fertilisation under irrigated conditions. Therefore, different maize hybrids performing variably under identical foliar fertilisation and irrigation treatments indicates genetic variability, specific nutrient-use efficiency and environmental adaptation.