| dc.description.abstract | Taro (Colocasiae esculenta L. Schott) popularly known as ‘nduma’ is an aquatic plant
grown for its edible leaves and corms. It is mainly cultivated in Western and Central
Kenya but its production is constrained majorly by Phytophthora colocasiae, a taro leaf
blight (TLB) disease. The disease causes destruction of leaf and corm. Knowledge
pertaining to taro association with the disease incidence, severity, index, Rainfall, R.H,
temperature, interrelationship between agronomic traits and disease resistance of Kenyan
and Pacific – Caribbean taro accessions remain unknown in Western Kenya. The study
was conducted at MMUST University farm, Maseno university laboratory and
greenhouse to determine disease incidence, severity, index, resistance and agronomic
traits of Pacific - Caribbean and Kenyan taro both in-vivo and in-vitro. Field experiments
were arranged in a C.R.D and replicated five times while the control experiments in the
greenhouse were blocked. Disease incidence was obtained by calculating the percentage
number of leaves infected per accession. Severity was derived from a subjective score
scale of 1-9 adopted from Simongo et al. (2016). Effect of R.H, rainfall and temperature
was determined based on disease incidence, severity and index vis a vis the
meteorological data obtained from Kakamega weather station. Number of leaves,
suckers, plant height and leaf surface area represented the agronomic traits. Relationship
between agronomic traits and disease resistance was determined by correlation and
dendogram analyses. Analysis of variance was used and significant means separated by
the L.S.D at 5% significance level. Disease incidence ranged between 17.71% - 29.86%,
severity 33.2% - 53.5% and index 0.71 - 1.54 for Pacific - Caribbean and Kenyan taro
respectively. The peak rainfall amounts of 174 and 223.9 mm, maximum temperature of
28.6°C and R.H range of 56 - 66% yielded the highest incidence, severity and index.
Disease resistance ranged between 58.27% - 89.73% for Kenyan and Pacific – Caribbean
taro respectively with BL/SM/128 portraying the highest resistance of 89.73% while
KNY/ELD/75 had the highest resistance (84.34%) among the Kenyan taro accessions.
Disease incidence and severity negatively correlated with number of leaves and corm
weight. Plant height was not affected by disease infection. BL/SM/120 had the highest
mean number of leaves (8.1) and KNY/KSM/20 had the lowest (4.6). The identified
tolerant taro accessions could be suggested for future breeding. Further evaluations
should be done on the identified taro under diverse environments and screening with
more virulent TLB isolates to aid in understanding disease pattern. These would guide in
ascertaining the right planting time to prevent disease epidemic and to develop accessions
with improved resistance and productivity. | en_US |
