The present invention provides a disposable sand cap for removing calluses and a callus removal device having the same. Methods for using such constructs in modulating the expression of endogenous andor heterologous genes are also disclosed, together with transgenic plants comprising such constructs. The account is automatically deactivated upon detecting a closure event associated with the trigger event, such as the closing of the trouble ticket, expiration of a predetermined time interval following detection of the trigger event, or occurrence of a predetermined time.