If the Earth were not tilted, what would be different about agriculture?
There wouldn’t be seasons, so I guess every region would get the same crops all year round, unless they decide to change them.
The combination of the Earth’s tilt, rotation, and orbit causes the seasons - precession and libration are the ‘proper’ words IIRC, the latter being vastly more important. No tilt does not mean no seasons, but the seasonal changes would be very much less and solely due to the changing distance between the Earth and the Sun.
And both Northern and Southern hemisperes would have winter at the same time.