Allometery and Productivity of Autumn Planted Maize Hybrids under Narrow Row Spacing

Modern maize (Zea mays L.) hybrids have the ability to tolerate narrow row spacing that helps enhancing yields per unit area. Variation in developmental plasticity and tolerance of present-day hybrids to reduced row spacing has been evaluated by using three maize hybrids for two years under field conditions. The objectives of the study was to determine whether hybrids belonging to different relative maturity groups respond differently in terms of growth dynamics and agronomic performance when grown at reduced row spacing of 60 and 45 cm compared with conventional rows of 75 cm. Results revealed that late maturing maize hybrid Pioneer-30Y87 exhibited not only maximum leaf area index, but exceeded in crop growth rate and plant height. During both the years of experimentation, early maturing hybrid DK-919 produced higher grain yield than mid and late maturity maize hybrids. Early (DK-919) and late (Pioneer-30Y87) maize hybrids performed best at 45 cm row spacing, while mid season hybrid (DK-5219) did best at 60 cm row spacing. Yield components such as cob length, number of grains per ear and 1000 grain weight significantly varied among maize hybrids and with varying row spacing. Although individual yield per plant (cob length, number of grains per ear, 1000 grain weight) decreased with reducing row spacing from 75 to 45 cm, but it was well compensated in early maturing hybrid than mid and late by increase in number of ears and number of grains per unit area. Study concluded that both early and late maize hybrids as DK-919 and Pioneer-30Y87can tolerate narrow row spacing but wider spacing is required for DK-5219-type hybrids. © 2010 Friends Science Publishers