ABSTRACT
Pre-harvest sprouting in its strict sense obviously depends on the germinability of the grain. Several factors influence germinability but one of the most important is the condition of the grain itself with respect to dormancy. Dormancy is the failure to germinate because of some internal block that prevents the completion of the germination processes ie. the conversion of an embryo into a seedling. Unlike seeds of many species cereal seeds or grains express their dormancy only when the temperature is relatively high. Respiratory metabolism became implicated in the dormancy mechanism largely as a result of the observations that cyanide and other respiratory inhibitors, high oxygen levels and several electron acceptors such as nitrate and nitrite all break dormancy. The special participation of TCA cycle in dormancy and germination has been invoked in the case of Avena fatua but more work is needed to assess its role in cereals. Dormancy develops early during grains development but may disappear later during maturation.
