Horticulture can be considered as a sub-branch of agricultural science. Both use almost the same techniques for crop cultivation but differ in some aspects like horticulture is done at small-scale like gardening and agriculture is practised at large-scale like farming. While agriculture deals with all aspects of crop cultivation, horticulture deals with vegetables, trees, flowers, turf, shrubs, fruits and nuts. 

Further Reading:

• Horticulture Cluster Development Program – HCDP
• Farm Acts, 2020 – Arguments For & Against