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Robusta CxR (Congensis × Robusta) hybrid coffee Photo: placeholder pending image-fill pass

Robusta CxR (Congensis × Robusta) hybrid coffee

CxR is an inter-specific hybrid coffee derived from a cross between Coffea congensis and Coffea canephora (robusta), released by the Central Coffee Research Institute, Balehonnur. It has become the dominant high-yielding robusta planting material in the Indian robusta belt — Wayanad (Kerala), Coorg, Hassan, Chikmagalur (lower elevations) and parts of Karnataka's robusta plains — alongside the older Selection 274 (S.274).

Key characteristics

  • Pedigree: Coffea congensis × C. canephora var. robusta
  • Released by: CCRI, Balehonnur
  • Yield: 1,500-2,500 kg clean coffee/ha under good management; among the highest among Indian robusta materials
  • Bean: bold, round, uniform; larger than S.274 robusta
  • Plant: vigorous, semi-erect; medium-tall canopy
  • Drought: tolerates moderate moisture stress; performs well under lighter shade than arabica
  • Cup: full-bodied, neutral robusta profile; well-suited to espresso blends

Cultivation

CxR is planted at 3 m × 3 m or 2.7 m × 2.7 m spacing (approximately 1,100-1,400 plants/ha), wider than arabica because of the larger canopy and self-sterility of robusta requiring cross-pollination. Robusta is self-incompatible, so block plantings of mixed clones or sib-line groups are needed for fruit set; isolated single-clone blocks set very poor crop. Shade is lighter than for arabica — a single upper-storey of silver oak (Grevillea robusta) is usually sufficient. Backing showers in April-May trigger flowering; the long fruit ripening window (8-10 months) is longer than arabica (6-8 months).

Pests and diseases

CxR is resistant to coffee leaf rust (Coffee Leaf Rust Hemileia Vastatrix) — a major advantage over arabica — and is not a host of the white stem borer Xylotrechus quadripes (Coffee White Stem Borer Xylotrechus). It is, however, susceptible to the coffee berry borer (Coffee Berry Borer Hypothenemus), which is the principal pest of Indian robusta. Mealybugs and shot-hole borer (Xyleborus) can occur in stressed blocks. Black rot in dense unpruned canopies during the south-west monsoon is managed by judicious thinning.

Processing and adoption

Indian robusta is processed predominantly by the dry (natural) method into "Cherry" grades, although washed "Parchment Robusta" commands a premium in European markets. CxR's bold bean and high outturn make it the preferred replanting material under Coffee Board subsidy programmes (Coffee Board Subsidy Replanting). India is the world's third-largest robusta producer after Vietnam and Brazil, with CxR forming a growing share of new plantings.

See also: Coffee Arabica Vs Robusta India, Coffee Arabica S 795 Selection, Coffee Shade Cultivation Silver Oak, Coffee Berry Borer Hypothenemus, Coffee Board Subsidy Replanting.

Sources

  1. Robusta Selections - CCRI Balehonnur. Central Coffee Research Institute.
  2. Coffee Board Robusta Database. Coffee Board of India.