Hello Stajuli, Tree tomatoes in normal circumstances start bearing fruit at 1-1.5 years however those propagated from cuttings or grafted have records of early flower setting and fruits bearing as earlier than a year old however proper and timely field management e.g weeding, fertilizer application and irrigation are a must do activities.
On withered crops, may I know is there's color change on leaves? Do you have enough rains? if not do you have irrigation program? Is it the whole farm or few scouted crops? A possible answers to these questions will help us to assist you. You can as well share photo of affected plants
Thanks