give a brief explanation on bud grafting..

Grafting is a technique where tissues from one plant are inserted into that of the other so that the two sets of vascular tissues join and grow together.  In bud grafting, a bud with small portion of surrounding bark is taken from the stem of a desired plant. This part will be called scion. It is then inserted into the small slit made in the bark of stock. Both are tied together and not allowed to dry. Buds of stock are not permitted to sprout. This method is widely practiced in rose, plums etc. 

It is very advantageous method and highly exploited for cheap and faster growth of plants. Like rose. The technique is usually performed at the peak of the growing season.