Özet:

Amaranthus species are annual weeds that are harmful especially in agricultural areas in Türkiye and around the world. Knowing when weed seeds will germinate and emerge helps effective program plans in weed management. This study was carried out in Erciyes University Faculty of Agriculture Plant Protection Department Herbology Laboratory between 2022 and 2023 in order to determine the germination biology of different Amaranthus species at different temperatures.In the study, the germination abilities of some Amaranthus species (Amaranthus albus L, Amaranthus chlorostachys, L. Amaranthus palmeri S. Watson, Amaranthus retroflexus L., Amaranthus viridis L.) at 8 different temperature levels (5, 10, 15, 20, 25, 30, 35, 40 ℃) were investigated. The research was carried out in 4 repetitions according to the random plot design. Trials were checked every day for 21 days and counts were made. In the observations made from the 1st day, the 0.5 mm emergence of the rootlet was accepted as germination and the germinated seeds were removed from the petri dishes. As a result of the experiment, it was observed that the temperature factor was effective on the germination of Amaranthus species. Among the Amaranthus species in the study, A. retroflexus seeds showed the highest germination at 35 ℃ (98.75%). The lowest germination was observed in A. viridis seeds at 20 ℃ and 35 ℃ (1.25%). A. viridis seeds showed the lowest total germination (4.68%) at all temperatures. A. palmeri and A. retroflexus seeds germinated 95% or more in the first 72 hours.