Effect of Chilling and Two PGRs on Seed Dormancy of Qare-Qat Berry (Vaccinium arctostaphylos L.)

Qare-Qat (Vaccinium arctostaphylos L.) seeds enter deep dormancy and require special conditions to break dormancy. The effects of chilling period, gibberellic acid (GA) and ethephon on Qare-Qat seed dormancy were studied in this experiment. The treatments were: A: GA at 3 rates (a(1)=0; a(2)=500; and a(3)=1000 ppm GA); B: Ethephon at 3 levels (b(1)=0; b(2)=10; and b(3)=100 ppm Eth); and C: length of chilling (c(1)=0; c(2)=4; c(3)=8; and c(4)=12 weeks chilling period). Data were collected for 90 days under darkness (in an incubator) and alternating light and dark (in germinator). Results revealed that under all treatments, seed germination under alternating light and dark conditions was better than in the dark. Results show that among the treatments, the best for breaking dormancy are: (1) 1000 ppm GA (in germinator or incubator), (2) 10 ppm Eth (in germinator) and no Eth (in incubator) and (3) 8 and 12 weeks chilling in germinator and incubator, respectively. Finally, two combination treatments, 1000 ppm GA + 8 weeks chilling period and 1000 ppm GA + 10 ppm Eth + 8 weeks chilling period, were the best treatments in all tests resulting in a 50% germination rate.