To edit a harvest, first access the harvest's details. In the Harvests module main screen, press the relevant crop to display all harvests of that crop, and then press the individual harvest entry to open its details screen. On that screen, press the edit button to open the harvest edit form.
Each harvest requires a crop, planting, amount, and unit. For amount and unit, a checkmark indicates that a valid input has been entered, and an exclamation point indicates that an invalid input has been entered. The form's Save button does not become active unless valid inputs are entered into all required fields.
The crop and planting options respect the Hide Inactive Plantings setting - if it is turned on, then only plantings that are currently between their scheduled Begin Harvest and End Harvest dates will be shown as options. However, if you are editing a harvest entry of a planting that is no longer considered an active planting by these criteria it will still be displayed as an option.
Note that the Unit and Status options are "editable dropdowns" - you can select an option from the popup list by clicking on the list icon, or you can type your own entry.
Once you've entered all of the necessary information, press the Save button to save the harvest. Alternatively, if you've changed your mind and don't want to save the harvest, you can press the back button to return to the main Harvests screen without saving your changes.