The present tense of tasted is taste(s).
taste
It is "taste/tastes".
have/has tasted
Yes, the sentence is in the present tense.
The present tense of the sentence "the oranges this season taste sour" is already in the present tense. It describes the current state of the oranges, indicating that they are sour this season. If you were to rephrase it, you might say, "This season, the oranges taste sour."
The oranges this season taste sour.
The word tastes is a verb. It is the present tense of taste.
The verb is is the present tense.
The future tense is will taste.
The past tense of did is did. The present tense of did is do. The future tense of did is will do.
It was, (past tense) it is, (present tense) it will be( future tense)
Past tense I had Present tense I have Future Tense I will have