EFFECTS OF HIGH-TEMPERATURES, ASH AND SEED POSITION IN THE INFLORESCENCE ON THE GERMINATION OF 3 SPANISH GRASSES

Seed germination of three perennial grasses, Agrostis curtisii, Avenul a marginata and Pseudarrhenatherum longifolium was studied in relation to the position (basal, intermediate, apical) in the panicle and two factors typically associated with fire, high temperatures and ash. Two similar germination responses were observed in A. curtisii and A. mar ginata: (1) germination rates were lower for seeds from higher positio ns in the inflorescence; and (2) watering with a plant-ash solution im proved the ability of apical seeds to germinate, but had the opposite effect on basal seeds. In A. curtisii, the latter response was also de pendent on whether or not the seed was exposed to high temperatures. I n P. longifolium the exposure to high temperatures and the position of the seeds in the inflorescence influenced the effect of ash. This cou ld be due to the different degrees of development of the seeds.