havesting in parts?

okey so my plant has buds that have matured to the quality i want. the last two nodes have buds that are still showing white hairs and clear trichs. is it alright to just cut off the top 3 nodes on the main stem?

I feel that buds on a marijuana plant are like tomatoes on a tomato plant..... They are not going to all be ripe at the exact same time. They will be all ripe within a short time of each other but not at the exact same moment. So pick the buds that look finished to you and let the others go a bit longer. When they look finished pick those.... It is a smart way to harvest any crop! (INCLUDING MARIJUANA!) Just don't rush things ..if you have 70% milky or orange trichomes pull the plant and harvest the lot