EVALUATION OF SELECTED SOIL ORGANIC AMENDMENTS FOR THE CONTROL OF COCOYAM ROOT ROT BLIGHT COMPLEX (CRRBC) IN UMUDIKE
Soil-borne diseases are the second most important limiting factor on crop yield after water insufficiency.
Xanthosoma spp production systems in particular are plagued by many intractable soil-borne diseases, like
cocoyam root rot blight complex (CRRBC). A trial was conducted in Umudike, South-East Nigeria to determine
the effect of selected organic amendment composts on the growth and yield parameters of Xanthosoma
sagittifolium (NXs 002-Ede Uhie) and to evaluate their effect on CRRBC incidence and severity under Umudike
conditions. The experiment was set up in a split plot treatment fitted into a randomized complete block design
(RCBD), at the Western Farm of National Root Crops Research Institute's (NRCRI) Farm, Umudike, South-East
Nigeria. Organic amendment composts [poultry manure compost (PMC), cow dung compost (CDC), swine dung
compost (SDC), and rice mill waste compost (RMWC)] occupied the main plots, while rates of amendment (0, 4,
8 t/ha) occupied the sub-plots. Treatments were replicated three times. Planting was done on plots measuring 2m
x 4m and at a spacing of 0.50m within rows and 0.50m between rows. Composted organic amendments
treatments were applied 2 weeks after sprouting. Blanket application of inorganic fertilizer (400kg/ha, NPK
15:15:15) was applied 6 weeks after planting (WAP). Plots were manually kept weed-free. Relevant agronomic
and pathological data were collected. All compost amendments improved growth parameters better than RMWC.
Tallest plants were obtained from control plots which were attributed to improved plant nutrition by the blanket
application of inorganic fertilizer. Highest corm yield and reduction in disease levels occurred in CDC amended
plots. Application of 8 t/ha CDC improved yield and yield parameters, and reduced CRRBC incidence and
severity of Xanthosoma sagittifolium (NXs 002 Ede Uhie) under Umudike conditions.