EFFECT OF THE PLANTING DATE ON THE QUALITY OF WHEAT SEED AT EL BAJIO, MEXICO

Seed quality is considered as a pattern that determines field performance or level of deterioration during storage; quality is used as an indicator of the seed value for specific purposes, including those related to distribution and marketing. The aim of this research was to evaluate the physical quality of the seed and the initial vigor of seedling derived from wheat (Triticum aestivum L.) genotypes as influenced by different planting dates. Thirty-six wheat genotypes were established on three planting dates: November 15 and December 15, 2015 and January 15, 2016 at El Bajio Experiment Station of the National Institute of Agricultural, Forest and Livestock Research, located in Celaya, Guanajuato, Mexico. The seeds were subjected to analytical tests for physical quality such as test weight and seed biomass under a completely randomized experimental design; in addition, a test was carried out in sand beds under nursery conditions to assess the initial seedling vigor through emergence speed and emergence percentage, fresh and dry shoot biomass, seedling height and vigor indices I and II using a randomized complete blocks design. There were statistically significant differences for genotypes and planting dates in the registered characters. The interaction genotypes by planting dates significantly modified the physical characteristics and the seedling vigor expressed through the emergence speed, seedling height and vigor index I. The planting date of November 15 was consistent with the highest values in most of the registered characteristics; therefore, it can be considered as the most appropriate planting date to produce quality seed for wheat planting.