OPTIMIZING WHEAT YIELD BY INTERVARIETAL CROPPING

The method of seeding wheat (Triticum aestivum L.) in ridges is increa sing in Mexico. This method allows interseeding of other cultivars by planting in the lower part of the furrow and makes it possible to grow two wheat genotypes with synergistic effects. The objective of this s tudy was to make better use of edaphic, aerial and chronological envir onment by using two different wheat cultivars to increase yield. Three field trials were conducted at the Yaqui Valley Experiment Station (C EVY-CIANO) in Sonora, Mexico during 1991-94. Wheat cv. Oasis F86 was f irst seeded on beds at 60 cm and irrigated next day. Tepoca M89, Rayon F89 and Baviacora M93 were interseeded at the 1st, 2nd and 3rd irriga tions. Oasis F86 yield was 3460, 6194 and 6261 kg/ha for the 1st, 2nd and 3rd interseeding date. The yield reduction in Oasis F86 resulted i n 1020, 286 and 279 kg/ha for the 1st, 2nd and 3rd intercropping date. Average yields for intercropped wheat were 3996, 532 and 371 kg/ha re sulting in a yield increase of 2976, 146 and 152 kg/ha for 1st, 2nd an d 3rd intercropping date. Total yield (Oasis F86 + interseeded) were 6 728, 7036 and 6944 for Oasis/Tepoca M89, Oasis/Rayon F89 and Oasis/Bav iacora M93 respectively. Intercropping at the Ist irrigation yielded 9 10 kg/ha more than the average check.