Evaluation of Latent Infection, Bio-deterioration and Yield of Colocasia esculenta (L.) Schott, Caused by Taro Leaf Blight Disease (Phytophthora colocasiae Raciborski)

Abstract

Taro leaf blight disease caused by Phytophtora colocasiae is a potential economic disease of the taro crop growing regions of Cameroon and other humid tropical regions of West and Central Africa. Studies were conducted at the International Institute of Tropical Agriculture (IITA) Yaoundé Nkolbisson to investigate latent infection bio-deterioration and yield of P. colcasiae on 10 improved and 4 local cultivars of Colocasia esculenta (L.) Schott (Taro), under the influence of latent infection by Phytophthora colocasiae the causal agent of leaf blight. Symptomless taro plants materials after incubation at room temperature of 24± 2°C for 10 days showed the presence of mycelia growth in more than 90% of the cultivars. This was an indication that symptom-less taro materials contained Phytophthora colocasiae that could only express itself under favorable environmental condition during the course of the growth and development of the host plant. There was a significant difference (p≤ 0.5) in corm number and weight of corms among all the cultivars. Resistance of taro cultivar to the P. colocasiae showed an influence on bio-deterioration potential of taro corms. Cultivar BL/SM144, White stem, Red and white stems corms did not deteriorate indicating they were resistant.