Efficacy of Calcium Carbide and leaves of <i>Croton aromaticus</i> and <i>Averrhoa bilinbi</i> in breaking dormancy of Oioscorea yams

The relative efficacy of CaC 2 Kappetiya (Croton aromaticus) and bilin (Averrhoa bilinbi) leaves in breaking the dormancy of Dioscorea yams (Dioscorea data L.) was compared in two experiments. CaC 2 treatment for 5 hours induced setts of var. Kahata angala to commence sprouting in 16.8 days, while a mixture of Kappetiya and bilin leaves applied for 4 days and only Kappetiya leaves for 5 days induced sprouting in 21.3 and 32.9 days, respectively. Moreover, the number of setts induced to sprout was 56% with all 3 materials when averaged over the 3 types of setts used. But Kapettiya and bilin leaves induced 85% sprouting in head setts as against 76.7% with CaC 2 . CaC 2 on the otherhand induced a larger number of tail setts to sprout. With variety Kiri khondol application of kappetiya and bilin leaves for 3 days and only kappetiya for 5 days induced sprouting in 16.6 and 17.6 days respectively ; and the percentage sprouting was 48.5 and 58.7, respectively. Untreated setts of Kahata angala and Kiri khondol commenced sprouting only after a rest period exceeding 120 days. In both varieties, and in all treatments, head and middle setts sprouted earlier and gave a higher % of sprouting than the tail setts. COCOS, (1984) 2 01-09 doi: 10.4038/cocos.v2i0.809