EFFECTS OF NITROGEN AND STAND DENSITY ON GRAIN YIELD PERFORMANCE OF HYBRID MAIZE (ZEA MAYS L.) IN A SOUTHWEST LOCATION

Abstract

The study investigated the response of hybrid maize (Zea mays L.) to N and stand density during the late season of 1990 and early season of 1991. Six maize hybrids were tested at three stand densities and four levels of N fertilizer (Urea) in a randomized complete block design with split - split plot arrangement.

Results showed that al/ the hybrids produced significantly higher grain yields at 75cm x 50 cm at two plants/stand than at 75cm x 50cm at one plant/stand and 75cm x 50cm at three plants/stand. Significantly higher grain yield was also produced at each successive higher N level. Even at the highest level of N (240 kgN/ ha) grain yield was still increasing. This suggests that the optimum N level may not have been reached. All the hybrids except that 8605-16 and 8239-15 significantly out yielded the open-pollinated checks. The highest yielding hybrids in late season were 8505-5, 8644-32 and 8605-16 while the highest yielding in early season were 8644-32 and 8644-31.