Effect of Temperature on Seeds Germination of Forage Sorghum

Germination tests of 5 hybrids of forage sorghum (Nutri Honey, Latte, Honey Graze BMR, Big Kahuna BMR and Sucrosorgo 506) were realized in laboratory conditions at temperature 5; 10; 15; 20; 25; 30; 35; 40; 45; and 50 degrees C in 2012. Germination dynamics, total germination (GT) and mean germination time (MGT) were evaluated. Seeds germination of all tested hybrids was determined in the range 10 - 40 degrees C. Only isolated seeds of hybrids Big Kahuna BMR and Sucrosorgo 506 germinated at temperature 45 degrees C. Total germination of sorghum seeds ranged from 88.7 to 91.5 % at temperature 15 - 35 degrees C in average of all hybrids. Significantly lowest values (alpha = 0.05) were found at temperature 10; 40 and 45 degrees C (total germination: 86.0; 78.5 and 1.2 %, respectively). Seeds germination was completed up to 4 days at 35 - 45 degrees C. Interval was longer (7 - 49 days) at 30 degrees C and lower temperature. Mean germination time extended with lower temperature (from 1.1 day at 40 degrees C to 11.8 days at 10 degrees C) in average of all hybrids.