ESTABLISHED COFFEE REPLACEMENT WITH RUIRU-11 - EVALUATION OF REPLACEMENT METHODS OF ESTABLISHED TRADITIONAL CAPPED COFFEE CV - FRENCH MISSION WITH THE NEW RUIRU-11 HYBRID

An evaluation of field replacement methods of established capped multi ple stem system Arabica coffee, ''French Mission'' with Ruiru 11 Arabi ca hybrid was carried out in Ruiru, Kenya. A non-significant enhanceme nt of Ruiru 11 stem height was observed in a mixed stand of Ruiru 11 a nd French Mission at hedgerow or staggered systems. Ruiru 11 trees rai sed on two stems, significantly increased the number of total primarie s per tree, had longer primary branches and higher number of nodes per primary branch than single stem system irrespective of the replacemen t methods. The highest number of bearing primaries per tree were obser ved on Ruiru 11 trees where French Mission was completely replaced or 50% was replaced by Ruiru 11. Complete replacement of French Mission t rees with Ruiru 11 at 5320 trees/ha. (1.37 x 1.37 m) raised on single stem, gave significantly high average yields of clean coffee. This was followed by the treatment involving 50% replacement of French Mission with Ruiru 11 at 2 x 1.5 m (3333 trees/ha.), trained on either a sing le or two stems and where Ruiru 11 was interplanted in French Mission at hedgerow system (2.74 x 1.37 m) trained on single stem. Large coffe e beans were noted to be reduced in high yields of clean coffee produc tion situations. Sequential replacement of established traditional cof fee with the new Arabica hybrid cv. Ruiru 11 was recommended.