Impact of moisture deficit stress at critical growth stages on growth and yield of hybrid maize

A field experiment was conducted in field no. 37F of Eastern Block Farm at Tamil Nadu Agricultural University, Coimbatore, India, during the summer season (January-May) of 2024 to assess the impact of moisture deficit stress at critical growth stages (knee high stage, tasselling, and grain filling stages) on growth and yield of hybrid maize. The growth parameters like plant height and dry matter production were significantly affected by moisture deficit stress. Significant decrease in the yield attributes such as cob length (cm), cob weight (g), number of grains per cob, 100-grain weight, shelling percentage (%), grain yield (kg/ha), and stover yield (kg/ha) was observed. Moisture deficit stress at the vegetative stage significantly reduced plant height and leaf area index. Studies revealed that grain yield and dry matter are significantly reduced in the reproductive stage (T4) and grain filling stage (T6) compared to control plants provided with irrigation at all critical growth stages (T7). The yield reduction was found to be higher at moisture stress for 20 days from tassel initiation (41%) and grain filling stage (34%) when compared with the irrigation without moisture stress (T7-control). The study concluded that moisture stress for 20 days from the tassel initiation stage caused more yield reduction (T4) followed by the grain-filling stage (T6). Moisture stress is more detrimental at the reproductive stage compared to the vegetative stage on maize yield.