RESPONSE OF WHEAT PLANTED AT HEXAGONAL PATTERN AT DIFFERENT POPULATION DENSITIES

Abstract

A field study was established at the Yaqui Valley Experimental Station, Sonora, during the 1992-93 wheat growing season. The objective was to determine the yield response to different population densities with different spacing distances among plants in an hexagonal pattem. Three planting dates (November 10, November 28 and January 10), three varieties (Bacanora T88, Oasis F86 and Tepoca T89) and four population densities (13,500; ,24,100; 54,300 and 217,400 plants/ha) were used. Results obtained indicate that all three varieties have a great tillering capacity (92, 80 and 67 tillers/plant for Oasis F86, Bacanora T88 and Tepoca T89, respectively), when they were in the best growing conditions: at 92 cm of equidistance among plants, seeded in November 10. Phenological stages were delayed with lower population densities; for example heading date was delayed 9, 14 and 12 days in Bacanora T88, Oasis F86 and Tepoca T89, respectively. Similar delay was observed for heading date. Yield was affected by planting date, population density and varieties. On average the hexagonal pattem did not outyield the conventional pattern. However, optimal yield was obtained with 200 thousand plants/ha which represents a planting density of 5.5 seed kg/ha.