SOWING PATTERNS AND PLANT DENSITIES INFLUENCE ON KERNEL FORMATION IN MAIZE

Abstract

The number of kernels per ear is the yield component most affected by plant density increases in maize (Zea mays L.). In this study the influence of planting patterns and plant densities on kernel formation of maize hybrids differing in plant characteristics, was determined. Two field experiments were conducted in Matamoros, Coahuila, México. In 1998, the hybrid 3025W was planted in two patterns (single rows 0.76 m and twin rows 0.90 m) and plant densities from 5.5 to 16.5 plants/m²; in 1999 the hybrids 3002W, 3025W, and N7590 were evaluated at plant densities from 5.5 to 15.5 plants/m² . The number of ovules per plant, ovule and kernel abortion, kernel number/m², leaf area per plant, and aboveground dry weight at flowering were determined. The number of ovules per plant was 8 % higher in twin rows 0.90 m than in single rows 0.76 m, but this increase did not produce a higher number of kernels/m², because in twin rows there was a significant increase of 2.2 % in ovule and kernel abortion per plant. When plant density was increased from 5.5 to 16.5 plants/m² the number of ovule per plant was reduced up to 42 %. This behavior was related with low values of leaf area per plant and aboveground dry weight per plant. The higher number of kernels/m2 in hybrids 3025W and N7590 was associated to a high number of ovules/m², and to low percentages of ovule and kernel abortion, as well as barren plants.