D. Njualem, H.A. Mendoza, J.T. Koi, P. Demo, V. Deffo and F.S. Nana
Twelve potato varieties Kondor, Escort, Famosa, Agria, Diamant, Desiree, Baraka, Spunta, Mondial, Premier, Cipira and Tubira were evaluated in two trials in Bambui, Cameroon, in 1995, to investigate the effect of late Blight damage on tuber yield and yield components of potato. Each trial had four replications of 20 plants per experimental unit. The first trial was protected against late and early blights while the second was unprotected. CIPIRA and TUBIRA with yields of 31.3 and 29.3 t/ha respectively in the protected trial, 39.7 and 36.7 t/ha, respectively in the unprotected trial significantly out yielded all the ten foreign varieties in both trials. The best of the foreign varieties were Kondor, Famosa, and Escort with yields of 25.0; 21.0 and 21.7 t/ha, respectively for the protected and 26.3; 27.3 and 23.3 t/ha respectively for the unprotected trial. Seven evaluations on late blight damage were made at weekly intervals for both trials. A 1-9 scale (1: no damage, 9: dead plant) was used to score late blight damage. CIPIRA, TUBIRA and Famosa each had a late blight score of 2 in both trials. These trials clearly show the superiority of locally selected late blight resistant varieties over all foreign varieties that have been traditionally cultivated in Cameroon.