Effect of Germınatıon Temperature on Germination and Seedling Growth Parameters in Cotton (Gossiypium Hirsutum L.) Varieties

Germination and seedling growth periods have a very important function in plant life. Especially in cases where abiotic stress conditions occur, these periods are of vital importance for the sustainability of plant life. Taking this into account, this research was conducted to determine the most suitable temperature for germination and seedling growth parameters of cotton varieties. In this research conducted under controlled conditions, germination and seedling development parameters of two cotton varieties (May-344 and Candia) were tested at 8 different temperature levels (8, 12, 16, 20, 24, 28, 32 and 36°C). It was determined that the germination percentage was 45.17-16.17%, the germination time was 4.06-3.94 days and the emergence rate index was 1.89-0.58 in May-344 and Candia cotton varieties, respectively. Moreover; root length 37.89-16.43 mm, stem length 44.69-41.00 mm, root fresh weight 22.40-19.51 mg, stem fresh weight 90.37-131.80 mg and the root/stem ratio was 0.26-0.16 mg/mg in May-344 and Candia cotton varieties, respectively. The results of the experiment revealed that most of the tested parameters were significantly affected by temperature. The highest germination rate, as the average of the two varieties and for both varieties separately, was obtained at 20 oC and no germination occurred at 8 oC. Except root to shoot ratio, other seedling growth parameters were maximum between 20-32 oC and decreased at higher temperatures.