What are the factors for which variety improvement of crop is done?

(a) Higher yield: It helps in the production of crop.
(b) Biotic and abiotic resistance: Crop should be resistant to biotic factors like diseases, insects, pests and abiotic factor like-drought, salinity, heat, cold, frost and water logging.
(c) Change in maturity duration : Short-duration maturity allows farmer to grow more crops in a year and reduces the cost of crop production.
(d) Wider adaptability: Crop should be able to adapt to changing environmental conditions.
(e) Desirable agronomic characteristics: The tallness and dwarfness of crop. Dwarfness required for cereals, so that less nutrients are consumed.