Effects of Population Density and Planting Pattern on the Yield and Yield Components of Leafy Reduced‐Stature Maize in a Short‐Season Area

Abstract

Maize hybrids that yield well, mature earlier with low grain moisture contents, tolerate higher population densities and take advantage of narrow row spacings better than the currently available hybrids would be more suitable for production in short-season areas. Leafy reducedstature maize hybrids, which have only recently been developed, have traits which address these criteria. The objective of this study was to evaluate the effects of different population densities (65 000 and 130000 plants ha"') and planting patterns (single rows 76 cm apart and paired rows with 20 cm between rows within a pair of 56 cm between rows of adjacent pairs) on the yield and yield components of two leafy reduced-stature (LRSl and LRS2), one non-leafy reduced-stature (NLRS), and two conventional corn hybrids (Pioneer 3979, <2500 CHU; and Pioneer 3902, 2600-2700 CHU) at two locations. All hybrids had higher kernel numbers per row and single plant grain yields at the lower population densities when in paired rows. However, as plant density increased, these variables decreased more in the conventional hybrids than the LRS and NLRS hybrids, which demonstrates the greater tolerance of the latter to the stresses associated with higher plant densities. Grain yield was higher for the two LRS hybrids and the NLRS hybrid at 130000 plants ha~' than 65000 plants ha '. Grain yield of conventional hybrids was reduced at the higher population density. The LRS hybrids matured before both conventional hybrids and out yielded Pioneer 3979 at the higher plant population density in both row spacings at both sites. Harvest index was not affected by population density and this value was not different among the NLRS and conventional hybrids. However, the harvest index of the LRS hybrids was greater than the others. LRS and NLRS hybrids had lower moisture contents and earlier maturities than conventional hybrids. Rapid growth of the first ear and higher harvest index values might are indications that LRS hybrids are more tolerant of higher population densities than the conventional hybrids.

Effects of Variety and Spacing on Yield Indices of Open-Pollinated Maize in Asaba Area of Delta State

“…This is consistent with the findings of Begna et al, (1997) who reported that higher grain yield among maize cultivar was due to the greater number of kernels that are formed in the ears which are more effective sink for carbohydrate synthesized in the leaves. It is also consistent with the findings of Ahmed and Sadek (1992) who reported that maize cultivars differ in their growth characters, yield and its components.…”

Response of Maize Grown Under High Plant Density; Performance, Issues and Management - A Critical Review

“…High plant population affected yield components by reducing the number of ears plant -1 , kernels per ear and kernel weight. As plant population increased kernel weight is more stable than other yield components [80][81][82]. Source-sink relationships during grain filling effected the kernel weight [83].…”

From Chemical Ecology to Agronomy: Cropping Systems in the Humid Northeast

“…At the same maturity, corn genotypes bearing the leafy trait have more leaves and leaf area above the ear, and are taller than conventional hybrids. A shorter vegetative period, longer grain-filling period, and higher yield potential were noted for Lfy than conventional genotypes, while reduced stature (rd1) types mature rapidly (Begna et al, 1997a(Begna et al, , 1997bModarres et al, 1997bModarres et al, , 1997cModarres et al, , 1998, making the Lfy and rd1 genotypes particularly well suited for short season areas. Most notable among corn genotypes bearing the Lfy trait are leafy reduced-stature (LRS, Lfy rd1) and leafy normal-stature (LNS, Lfy) genotypes.…”

“…The earliest studies of genotypes carrying the Lfy trait were focused on aspects of crop physiology (Modarres et al, 1997a(Modarres et al, , 1997bBegna et al, 1997aBegna et al, , 1999Begna et al, , 2000Dijak et al, 1999), mathematical characterization of canopy characteristics Dwyer, 1993, 1999), concentration of soluble sugars and starch and ear position and green leaf area duration . A few researchers have attempted to determine management requirements for Lfy hybrids, particularly their response to population density (Begna et al, 1999) and weed competition (Begna et al, 1997a(Begna et al, , 1997b(Begna et al, , 1999.…”

“…A few researchers have attempted to determine management requirements for Lfy hybrids, particularly their response to population density (Begna et al, 1999) and weed competition (Begna et al, 1997a(Begna et al, , 1997b(Begna et al, , 1999. The most noticeable differences between Lfy-bearing corn genotypes and conventional hybrids are their canopy architectures ( Figure 3).…”