Row Orientation and Plant Space in Relation to Nitrogen Fertilizer Application Response on Maize Production

Canopy architecture performance for assimilate production might be altered with changes in row orientation and/or plant spacing within rows and might influence traits that affect yield. The field experiment was, therefore, designed to study the N treatment effect (0, 100, 150 and 200 kg ha -1 ) under contrasting row spacing (RS i.e. 50x30 vs. 70x20cm) and row orientation (RO i.e. North-South = NS vs. East-West = EW). The experiment was conducted in split plot, randomized complete block design in three replications. Planting was done on June 20, 2009 (cv. Jalal). Basal application of P (100 kg ha -1 ) and K (50 kg ha -1 ) were applied uniformly at sowing. Nitrogen application was split: half at sowing and other half 30 days after sowing (DAS). Growth phenology significantly delayed for tasseling in the NS and for silking in the EW. The 50x30 spacing delayed tasseling with significant effect on ROxRS interaction. The N affected emergence, silking and tasseling with significant changes for the N interaction with spacing. Mean leaf area was noted higher (P<0.05) at EW at anthesis and maturity. Spacing did not influence leaf area. The canopy area index (CAI) was statistically higher at NS orientation and 50x30 spacing. Higher N showed higher leaf area at maturity. Interaction of N with RO and RS influenced CAI but not the leaf area. Among the yield traits, higher ear number (m -2 ) and grain weight (g) was recorded for NS and higher grain number (ear -1 ) for EW orientation. Likewise, plant mortality, grain number and weight were observed higher in 75x20 spacing with a significant difference in traits by the interaction of RSxRO. The N 150 kg ha -1 than any lower N treatments showed lower plant mortality during growth, higher era number, grain number and weight. Similarly, taller plant was observed in NS with no changes in dry matter, grain yield and harvest index by RO. A lower height with higher dry matter and grain yield was noted for 50x30 spacing. Interactive responses of the ROxRS were significant for plant height, dry matter and grain yield. Higher, the N application did not produce taller plants but did produce higher dry matter and grain yield. Both yield and dry matter did not change in N 150 and 200 kg ha -1 . The study concludes a marked effect of spacing under the orientation on canopy architecture to alter yield traits. Under the soil fertility status, environment and variety potential, N 150 kg ha -1 is the optimum application rate.