Response of Cocoyam (Xanthosoma mafafa) Growth, Yield Parameters and Soil Physical Properties of Ultisol at Umudike, Southeastern Nigeria

Abstract

Aim: To determine the effect of different rates of sawdust (SD) and poultry manure (PM) applied on some soil physical properties of acid sandy Ultisol, and some growth parameters and yield of cocoyam.
 Study Design: 2 x 5 factorial arrangement in a randomized complete block design replicated three times. 
 Place and Duration of Study: The experiment was conducted in Eastern farm of Michael Okpara University of Agriculture, Umudike during 2014 and 2015 planting seasons.
 Methodology: The treatments comprised of two manure sources at five levels each: sawdust (0, 2, 10, 15 and 20t/ha) and poultry manure (0, 2, 4, 6 and 8t/ha). The treatments were assigned randomly to the plots and incorporated into the soil two weeks before planting. Data were collected on plant height, number of leaves, leaf area, corms, cormels and total yield. Soil samples were collected with core samplers for physical properties such as Soil Bulk density and Total Porosity. All the data collected were subjected to ANOVA for factorial experiment in RCBD at 5% probability level.
 Results: The result showed that the interactions of poultry manure and sawdust significantly (p<0.05) improved soil bulk density and total porosity with the lowest value obtained with 0t/ha SD + 8t/ha PM in both 2014 and 2015. The result showed that the interactions of poultry manure and sawdust significantly (p<0.05) increased the leaf area with the highest value obtained with 20t/ha SD + 8t/ha PM in both 2014 and 2015. Also, only the increasing rates of treatment applied significantly (p<0.05) increased the number of leaves, plant height, leaf area and cocoyam yield with the highest value obtained with 20t/ha SD + 8t/ha PM. Also, the various rates of treatment application significantly (p<0.05) increased the cocoyam yield (weight of corms and cormels) with the highest value obtained with 20t/ha SD + 8t/ha PM.
 Conclusion: Improvement in growth and yield of cocoyam resulted from the improved nutrient status of the soil as a result of the amendments applied.