Robusta (Coffea canephora)
Robusta, as the name implies, grows vigorously (compared to Arabica). It is a diploid species (2n=22) and has broad, large leaves that are pale green in colour. Flowers are fragrant and borne in compact clusters at each node. The number of flowers per node are higher than in Arabica.
Under the climatic conditions of South India, the buds initiate during November and are ready for blossom in February and March, on receipt of summer showers or by irrigation. The flowers open on 7th or 8th day after rains.Unlike Arabica, Robusta is self incompatible, i.e. the ovule of some flower cannot be fertilized with its own pollen. Hence, cross pollination is essential in Robusta. The fruits mature in 10 to 11 months and generally ready for harvest two months later than Arabica C. canephora is shallow rooted and susceptible to drought. The quality of Robusta coffee is inferior to that of Arabica in bean size as well as in organoleptic characteristics like aroma, flavour and taste.