GRAIN GROWTH COMPONENTS OF MAIZE PROLYPHIC CULTIVARS

Abstract

Maize grain yield is determined by grain number per plant and the individual grain weight, the last one is defined by the effective Maize grain yield is determined by grain number per plant and the individual grain weight, the last one is defined by the effective grain filling period and grain filling rate; these have relationships among them and with environmental factors which impact on growth and plant development. The objective of this investigation was to determine the effect of population density on grain biomass accumulation of maize prolyphic cultivars. Six cultivars were evaluated at Güemez Tam. in three population densities: 25 000, 50 000 and 75 000 plants/ha. The individual grain weight, effective grain filling period and grain filling rate were determined in primary and secondary ears. When population density increased from 25 000 to 75 000 plants/ha the individual grain weight decreased in 8 and 9 % in primary and secondary ears, respectively, due to a lower grain filling period. Population density did not have effect on grain filling rate in primary and secondary ears. The H-437 cultivar had the largest individual grain weight in primary and secondary ears at 294.2 and 287.5 g, respectively, due to its highest grain filling period (42.4 and 41.6 d, respectively) and grain filling rate (6.90 y 6.91 mg d-1 respectively); the individual grain weight and grain growth components were significantly highest in the primary ears (P>0.05) that in the secondary ear. grain filling period and grain filling rate; these have relationships among them and with environmental factors which impact on growth and plant development. The objective of this investigation was to determine the effect of population density on grain biomass accumulation of maize prolyphic cultivars. Six cultivars were evaluated at Güemez Tam. in three population densities: 25 000, 50 000 and 75 000 plants/ha. The individual grain weight, effective grain filling period and grain filling rate were determined in primary and secondary ears. When population density increased from 25 000 to 75 000 plants/ha the individual grain weight decreased in 8 and 9 % in primary and secondary ears, respectively, due to a lower grain filling period. Population density did not have effect on grain filling rate in primary and secondary ears. The H-437 cultivar had the largest individual grain weight in primary and secondary ears at 294.2 and 287.5 g, respectively, due to its highest grain filling period (42.4 and 41.6 d, respectively) and grain filling rate (6.90 y 6.91 mg d^-1 respectively); the individual grain weight and grain growth components were significantly highest in the primary ears (P>0.05) that in the secondary ear.