EFFECT OF ROW SPACING, FERTILIZATION AND POPULATION OF PLANTS PER HECTARE ON GRAIN YIELD AND OTHER AGRONOMIC CHARACTERISTICS OF TWO CORN HYBRIDS UNDER IRRIGATION CONDITIONS, IN CHAPINGO, MEX.

Abstract

Two hybrids (H-28, recommended for raingall season planting, and H-129, recommended far irrigation planting), three distances between rows (92, 76 and 50 cm), two plant densities (60,000 and 80,000 plants/ha) and three doses· of fertilizer (120-60-0, 160-60-0 and 200- 60-0) were studied. The following characteristics were analysed: gra­in yield, plant height, plants with two ears, barren plants, number of tillers, number of plants at harvest and length and diameter of the ear. The principal conclusions were: 1) The actual recommendations for grain crop in this area are the most adequate for the lype of late corn which are being discussed. 2) H-28 showed greater tolerance to planting in high populations and equal grain yield than H-129. 3) Confirmation of the yielding capacity of H-28, in future irrigation experiments, will make it possible to have an earlier hybrid, saving on cultivation cost. 4) It is recommended that ali improved varieties obtained be tested in different environmental conditions to determine those in which the maximum ) yield potential is expressed, 5) It is necessary to develop new materials with other characteristics (such as dwarfing and erect leaves) in order to get a better utilization of the environment.