Growth Performance of Maize (Zea mays L.) under Different Micro-climatic Regimes

A field experiment was carried out during rabi, 2021-22 at the Instructional-Cum-Research (ICR) Farm of Assam Agricultural University, Jorhat to study the influence of weather on rabi maize (cv. DKC-9081) grown under different micro-climatic regime (MR-I: 15th October, MR-II: 30th October, MR-III:15th November, MR-IV: 30th November and MR-V: 15th December), following a randomized block design (RBD) with four replications. Biometric observations, viz., leaf area index, plant height, total dry weight production, number of cobs per plant, cob weight, cob length, cob girth, number of rows per cob, number of grains per row, 1000 grain wt., and grain yield were recorded. The optimum sown crop (15th October) took 130 days from sowing to maturity, while the 15th December sown crop took 155 days to mature. A gradual increase in the duration of the total growing period was observed in late-sown crops. The PAR interception was maximum in the case of the crops sown under MR-I (81.21%) followed by MR-II (79.60%), MR-III (60.0%), MR-IV (56.05%) and MR-V (42.97%). The higher number of cobs per plant (1.57) and higher cob weight (201.8g) were observed under MR-I. The leaf area index (LAI) and total dry weight were found to be highest under MR-I and the lowest under MR-V. Overall, the highest grain yield was recorded for the crops sown on 15th October (5106.25 kg/ha) as compared to other dates of sowing. The grain yield declined up to 33 per cent when seeds were sown during the first fortnight of December (MR-V) compared to the early sowing (MR-I). Correlation studies revealed that there is a significant relationship between grain yield, maximum LAI, total biomass, and cob weight with meteorological parameters computed for different growth stages of the crop. It shows that the grain yield was significantly negatively associated with minimum temperature during the reproductive (-0.96**) and maturity (-0.94**) phase and rainfall during the maturity (-0.87*) phase.