Determination of some biological properties of the seeds of the Johnson grass (Sorghum halepense (L.) Pers.)

Dormancy is an important factor affecting seed germination and the emergence of weeds. In this study, the intensity of dormancy in freshly collected seeds of Sorghum halepense (L.) Pers. was determined, and various methods to break this dormancy were evaluated. These methods included sulfuric acid application, sanding, soaking in distilled water, folding method application, and gibberellic acid application. Additionally, the study aimed to determine the optimal, maximum, and minimum germination temperatures and assess seed germination at different burial depths. According to the experimental results, the most effective method for breaking dormancy was the application of 62.5% sulfuric acid for 30 minutes. The ideal germination temperature was found to be 30°C, with a germination rate of 87%. The minimum temperature for germination was 15°C (6% germination), and the maximum temperature was 40°C (48% germination). In terms of sowing depth, the highest germination rate was observed at a depth of 3 cm, where 50% of seeds germinated. It was also noted that the germination rate gradually decreased with increasing burial depth. The results of these experiments provide valuable information on effective methods for breaking seed dormancy in Sorghum halepense and offer insights into the optimal conditions for seed germination.