The objective of this paper was to study the germinative process (sprouting) of the grains in the head, the grain yield, the adaptability and stability in responsive wheat (Triticum aestivum L.) genotypes to environmental variations. The experiments were carried out at the Núcleo Experimental, Instituto Agronômico, in Campinas, SP, Brazil, in the period 1996-98. The germination of grains in the head was evaluated by the Falling Number method, which consists in establishing the alpha-amylase levels of activity in the grains. The second and third harvest times occurred at seven and fourteen days after the first harvest time. Harvest delay showed grain yield reduction mainly at the third harvest time; the alpha-amylase levels were also higher at the third harvest time, due to degradation of the exposed grains to the weather. The IAC 289 genotype presented adaptability to favorable environment, but susceptibility to the occurrence of the sprouting process. The genotypes IAC 24, Mochis, IAC 370 and IAC 351 were the most resistant to sprouting, showing low alpha-amylase activity.
Triticum aestivum; germinability; alpha-amylase; sowing date
