Plant Population Density x Sowing Date Interaction in Wheat

Abstract

Wheat yield response to sowing date is very well known in Northwest of Mexico; however, sowing date x plant population density has not been studied before. The objective of this work is to set wheat performance at early sowing date when using low plant population density. Six experiments were carried out during two years (1994-96) planting in three different sowing dates (November 15, December first and January 10). Each of these experiments contained five plant population densities treatments (13.5, 24.1, 54 and 217 thousand plants/ha plus a check with 120 kg seed/ha) with three cv: Bacanora T88, Oasis F86 and Tepoca T67. Plant population densities x sowing date interaction was significant. This was due to a higher yield with 117 thousand plants/ha than the check in early dates (end of November) and the opposite in later dates. Plant population density x sowing date x variety interaction was also significant. This was due to the fact that Tepoca T87 response to any increment in seed dosage even in early sowing date. The optimum plant population density was 200 thousand plants/ha for November 15 and 260 for December first. Plant population density response was explained mainly by the tillering capacity of wheat, and sowing date response was mainly due to kernel weight.