Fourth Amendment Issues

While on routine patrol, the police helicopter’s pilot notices a field of marijuana growing in Farmer Brown’s field part of which is fenced off and the fence encompasses the house. The police respond and relieve Farmer Brown of his crop and put Farmer Brown in jail on drug charges. The police do not need or have a search warrant. True or False.
The police make a traffic stop for excessive speed. As routine procedure, the officer asks the operator if he (the officer) can search the vehicle. Keep in mind that a citation is in fact a form of arrest and the recipient is honor bound to pay the ticket or go to jail. The officer is suspicious and the operator gives consent.  Does the officer need a warrant?
A search warrant has been issued and the person(s) and place to be searched and the items to be seized appear on the warrant. In executing the search warrant, police see several items of incriminating evidence unrelated to the warrant. While moving stuff around, in the place of search, additional items are found and still unrelated to the warrant yet, are incriminating and detract for the credibility of the suspect(s). The police bag all evidence found and arrests the occupants of the residence whose names appear on the warrant. The officers followed procedure and complied with the confines of the warrant? True or False