Disowning the Shemitah produce of one’s land:
Every owner that contains a Kedushas Shemitah product in his field must disown the product and give entrance for all people to be able to come and partake from the food.
Vegetables: Fields of vegetables which grew during the 6th year must be disowned during Shemitah.
May the food be eaten if it was not disowned and was rather guarded from people?
How to be Mafkir the produce:
Must one remove tithes from Shemitah produce that was not disowned?
Some Poskim rule that all Shemitah produce that was not disowned as required by law must have their tithes removed. Others rule that it is not necessary to tithe any Shemitah produce even if it was not disowned. Practically the tithes are to be removed without a blessing.