Sln.6 backcrosses a Robusta x Kent hybrid to Arabica, giving Indian growers an Arabica-looking tree with Robusta vigour and field tolerance to rust.
Sln.6 is a tall Central Coffee Research Institute selection from an interspecific cross of the Robusta clone S.274 with the Arabica variety Kent, then backcrossed to Kent. Second-backcross progenies looked like Arabica but kept Robusta vigour and a high level of field tolerance to rust, per WCR. CCRI distributed it to Indian farmers in the 1970s and shared it with Rwanda, Kenya, Zimbabwe and Uganda in 2010. Like other Indian introgressed lines it is considered susceptible to rust in India's own high-diversity rust-race environment despite testing resistant in WCR's global trials.
Field notes
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Rwanda's agriculture board selected its variety RAB C15 from Sln.6 material that CCRI shared in 2010.
Family tree
Sln.6 is a backcross of S.274 and Kent.
Grown in
- Indiaorigin
Sources · 5 Every sentence here was checked against a source we read. Taste notes are what guides describe, not promises about your bag. Last revised 2026-11-11.
- Arabica Varieties — A global catalog of Arabica coffee varieties from around the world (PDF, rev. Sept 4, 2025) · World Coffee Research
- India's Arabica Coffee Varieties · Counter Culture Coffee
- Coffee Varieties in India · Indian Coffee Culture
- Sln.6 (WCR Varieties Catalog) · World Coffee Research
- Horticulture, Plantation Crops, Coffee (Varieties) · Tamil Nadu Agricultural University