EFFECT OF PLANT DENSITY ON KERNEL, NIXTAMAL AND TORTILLA QUALITIES OF HIGH QUALITY PROTEIN MAIZE HYBRIDS

Abstract

The effect of plant density on commercial and protein qualities of kernels and tortillas from three maize hybrids (Zea mays L.) was studied. Hybrids were two quality protein hybrids (QPM) developed for the Highlands of México (‘H-143C’ and ‘H-149C’) and one non-QPM (‘Promesa’). All hybrids were grown at 67 000 and 80 000 plants ha^-1. Planting density, as well as genotype interaction affected commercial quality and chemical composition of QPM hybrids. Crop management with 67 000 plants ha^-1 allowed production of QPM hybrids with quality for the “masa” (maize dough) and tortilla industries. ‘H-143C’ hybrid showed similar quality at both planting densities, while ‘H-149C’ hybrid produced softer kernels containing low protein (8.6 %) and tryptophan (0.73 %) when grown at 80 000 plants ha^-1. QPM hybrids had better protein quality compared to ‘Promesa’, the non-QPM hybrid control. Freshly prepared tortillas with QPM hybrids grown at low densities were whiter and softer than the tortillas from the control. The two QPM hybrids grown at density of 67 000 plants ha^-1 are an excellent choice for the “masa” and tortilla industries because their tortillas have improved commercial and protein qualities compared to non-QPM control ‘Promesa’.