Upon the return of a verdict in a proceeding to acquire property for a public improvement, if no motion for a new trial is made, or if made, is overruled, the petitioner, within 90 days after final judgment as to all defendants, both as to the amount of damages and compensation to be awarded and benefits to be assessed shall elect whether it will dismiss the proceeding or enter judgment on the verdict. If it elects to enter judgment on the verdict, it shall become bound thereby and liable to pay the amount thereof, whether the assessment is collected or not, and the judgment of condemnation shall not be conditional. But the judgment shall not draw interest until the petitioner takes possession of or damages the property, in respect to which the judgment is entered. After entry of judgment the petitioner shall not be permitted to withdraw from or to dismiss the proceeding, without the consent of all parties whose land is thereby condemned, except as hereinafter provided. In case an appeal is taken by either party from the judgment of condemnation or confirmation, then unless the petitioner files in the cause its written election to proceed with the improvement notwithstanding the appeal, no steps shall be taken to collect the assessment nor to compel payment of the compensation awarded until the appeal is disposed of and final judgment entered in the cause, or, in case of reversal, until there is a new trial and judgment. However, in case of a final reversal the petitioner may still elect, within a period of 60 days, to abandon the proceeding.