What prevention do for tuber formation in potato

40 days after sowing of potato crop, measures should be taken to increase tuber size
To grow tubers, first spraying should be done @ 00:52:34 @ 1 kg / acre.
After this, a second spray should be done 10-15 before harvesting of potatoes @ 00:00:50 @ 1 kg / acre and with this paclobutrazol @ 40% SC @ 30 ml / acre.