With 2 tractor teams working for 2 days, this is like 2*2=<<2*2=4>>4 days worth of work by a single tractor, which they call tractor days.
With 5 tractor teams working for 4 days, this is 7*3=21 tractor days.
In total, the effort of all the tractor teams is 4+21=<<4+21=25>>25 tractor days.
If they need to plant 1700 acres with their 25 tractor days, then each tractor team needs to plant 1700/25 = <<1700/25=68>>68 acres of cotton per day.
#### 68