Pre-harvest Dormancy Breaking of Potato Seeds by Gamma Rays Irradiation and Application of GA3 Solutions

Abstracts . After harvesting, potato seeds stay dormant for about 8-12 weeks, causing lots of disadvantages for potato seed industry. Many  reports on dormancy breaking of potato seeds have been published. However, all the works were carried out after the potato seeds were harvested and in small scale, which become non-practical for industrial scale. Therefore, a research to find out an easy, efficient, and effective method on breaking the dormancy of potato seeds need to be done.  A new approach needs to be taken, which is breaking potato seeds dormancy before the seeds are harvested. The objective of this research were to determine the effects of gamma rays irradiation, application of GA 3 solutions, and their interaction on pre-harvest dormancy breaking of potato seeds dormancy. The experiment used Randomized Complete Block Design (RCBD) arranged in factorial (2 factors; 10 replications). Potato seeds were irradiated with gamma rays (0, 30 GY), planted in the polybag filled with 5 kg of sterile media, and incubated at the medium altitude of Northern Bengkulu District. When the crops were 6 weeks old after emergence (WAE), they were sprayed with GA 3 solutions (0. 50. 100 ppm) and repeated every weeks after ward until harvesting. The variables measured included time of shoot emergence, number of shoots, height of shoot, number of shoot node, number of leaves, number of roots, and root length. The results showed that the interaction between gamma irradiation and application of GA 3 significantly affected the dormancy breaking of potato seeds demonstrated by precarious sprouting of the seeds, more number of shoot emerged, taller shoot, more number of roots, and longer roots. In contrat, there was no shoot and root produced without GA 3 application and gamma irradiation. Keywords: Dormancy breaking, potato seeds, gamma rays, GA