K7 is known for its tolerance to rust and coffee berry disease, and has been widely used in modern breeding programs in Kenya and Tanzania.
K7 was released in Kenya in 1936 after five generations of selection from the original population by Scott Agricultural Laboratories (for a history of Scott Labs see SL28. It is still widely planted in Kenya.
According to P. A. Jones, an agricultural officer at Kenya’s Coffee Research Station in the 1950s, K7 is one of two trees selected in 1936 by Mr. R. H. Walker from French Mission trees on his Legetet Estate in Muhorohi (for more on French Mission, see SL34. One of these selections, later named K7, was apparently immune to coffee leaf rust for several years (the variety is no longer resistant).
Recent genetic tests have confirmed that K7 is related to the Bourbon genetic group.