Is it permissible to delay ghusl from janabah until after the prayer time due to time constraints, and suffice with wudu and prayer, then perform ghusl after finishing work?

Purity from the two impurities (major and minor ritual impurity) is a condition for the validity of prayer. Delaying the ritual bath for someone in a state of major ritual impurity (junub) until the prayer time expires is impermissible. If a Muslim is unable to perform the ritual bath and fears harm to his property or livelihood, then he should perform as much of the ritual bath as he can, perform tayammum (dry ablution), and pray, and there is no repetition (qada') required of him. It is obligatory to make up the missed prayers that were performed without ghusl (ritual bath) or tayammum.