Integrated effect of irrigation rate and plant density on yield, yield components and water use efficiency of maize.

We investigated, under field conditions and during four years (2018–2021) the effects of five irrigation levels (T1: 100% of crop water requirement; T2: 80% of T1; T3: 60% of T1; T4: 40% of T1, and T5: 0% of T1 – rainfed) in interaction with three planting densities (PD1: 54 900, PD2: 64 900, and PD3 75 200 plants/ha) on the yield, yield components and water use efficiency (WUE) of maize in Srem, Serbia. The results indicate a large year-to-year variability, mainly due to the total amount and distribution of rainfall. Water regime and PD interacted significantly. Irrigation increased grain yield 28, 34, 30 and 18% for treatments T1, T2, T3 and T4, respectively, compared to the T5; and significantly influenced the yield components. Planting density had significantly lower effects on grain yield compared to irrigation (+1.4–1.8%). WUE is maximised (3.436 kg/m3) at T4 under 75 200 plants/ha. Grain yield and WUE increased significantly with increasing PD, while the number of grains per ear and the weight of 1 000 grains decreased with increasing PD. In conclusion, limited irrigation at T2 under PD2 may be a viable method to maximise production efficiency and maize yield under the environmental conditions of this study and at sites with similar soil and climatic conditions. [ABSTRACT FROM AUTHOR]