the large majority of black africa was under european rule for only 60-80 years...your assuming alot if you think white people are responsible for what africa is today based off of that tiny timeframe of rule.
And if your theory was correct, and not just a repeat of what some people expect everyone to believe [usually from talking heads on tv/books]. It would be rather obvious to look at other areas which were colonized just like africa was, and colonized for far longer than africa and expect worse results.
That would include india, vietnam, indonesia, singapore, and a shitton of other countries outside of africa. Most of those were under a european nation's rule for atleast 400 years, yet most of those countries are doing fine, and a few even rival our own when it comes to technology, cleaniness and unemployment/crime [singapore, hongkong]. And the ones that are not doing fine ? They are still doing better than subsaharran african countries.
Oh and they also had, and have more 'colonial' farming going on than africa ever has. Ever heard of java coffee ? Its from indonesia and introduced by the dutch and farmed there. Yet thier not a starving country.
Africa's real problem with 'farming' isnt white people, thats a nice copout. Its the native people there doing slash and burn on unproductive jungle land, farming it for a year or two until nothing grows there anymore, then moving on to burn more jungle. Rinse and repeat. Zero management of thier current farmland is why the saharra desert is spreading south in countries bordering that desert. And is why famine is so common in other african countries like ethiopia where they destroyed the good farmland they did have by not managing it right.
But i guess its easier to just lay blame on whitey and not on the people there, or those running those countries. Afterall, with people like mugabe in zimbabwe who killed most of his countries white population [who also were the large scale farmers, who also fed the entire population and then some] you really do have a strong point. Surely in that case it was the white man's fault that he was feeding that entire country with his evil modern technology farming, and its his fault that black people are starving there now since mugabe had them all killed.
The opposite of sub-saharran african countries of course, is china and how they are handling thier desertification problem. Instead of blaming an entire other race, or other people in general. They blame themselves for allowing huge dust storms to cover half thier country since they mismanaged thier land. Thier reaction ? Not blaming whitey, but sending out scientists to diagnose and fix the problem. Pretty amazing that.
Anyways, i blame the natives in sub-africa for most of thier problems. If other colonized countries lack the same problems that they have, then the argument doesnt hold up in my book. And blaming others for them doesnt help anything but just keeps them complacent to blame others and do jackshit for themselves.