BREAKING DORMANCY OF POTATO MINITUBERS WITH THIOUREA

Abstract

We investigated the effects of postharvest application of thiourea in various concentrations (0, 10, 20 and 30 g/ l) and with different incubation times (1, 2 and 3 h) on breaking of dormancy and sprouting of potato (Solanum tuberosum L.,cv. Marfona) minitubers using two ages (freshly harvested and one week after harvest). Thiourea treated minitubers showed significantly shorter dormancy, especially when minitubers were treated immediately after harvest. Higher concentration of thiourea was more effective in one week old minitubers. In freshly harvested minitubers, only 2 hours of thiourea treatment resulted in low level of dormancy, but in one week old minitubers, 3 hours was more effective. Dormancy breaking was associated with removal of apical dominance and therefore thiourea treatment increased the number of sprouts per minituber, especially in freshly harvested minitubers. The number of sprouts had a positive correlation with concentration and incubation time. The length of sprouts increased with higher thiourea concentration. These results showed that the optimal thiourea treatment was the right combination of minituber age, concentration and duration of incubation.