EFFECT OF SEEDING DEPTH AND TEMPERATURE ON TILLERING CHARACTERISTICS OF FOUR SPRING WHEAT CULTIVARS

Abstract

This study was conducted to investigate the effects of seeding depth and temperature on tillering patterns of cultivars of spring wheat (Triticum aestivum L.) with diverse tillering capacities. Four cultivars (Ingal, Neepawa, Pitic 62 and Potam) were grown at three seeding depths (3, 6 and 12 cm) and two temperature regimes (10/5 °C and 20/10 °C) in a controlled environment. Times to emergence of individual tillers were recorded as were their biomass, leaf area and leaf number at the time of main stem spike emergence. Increasing the seeding depth from 3 to 6 cm delayed seedling emergence, and reduced and delayed emergence particularly of the coleoptilar (TO) and first leaf (T1) tillers of all cultivars. Increased temperature resulted in reduced time to seedling and tiller emergence for all cultivars, increased (+13%) final tiller number in Pitic 62, little change in final tiller numbers of Neepawa and Ingal, and a significant reduction (−24%) in final tiller number for Potam. Pitic differed from other cultivars in having a vernalization requirement that affected its response to temperature. Potam differed from the other cultivars in showing an increase in main stem apical dominance with increased temperature. Tillers which had produced a minimum of three or four leaves, depending on the cultivar, had not senesced at the time of main stem spike emergence.Key words: Wheat (spring), tillering, seeding depth, temperature, cultivar-environmental interaction