The Effcets of Irrigation and Fertilizer on Growth, Yield and Shelf Life of OFSP [Ipomea Batatas (L) Lam] Roots in Four Storage Structures

Abstract

The objective of the research was to investigate the effects of irrigation levels, poultry manure (PM), cow dung (CD), NPK and their interactions on the growth and yield, quality and shelf life of Orange Fleshed Sweet Potato (OFSP) in evaporative cooling structures. Sixteen treatments (four levels of irrigation and four soil amendments) with three replicates were laid out in a Randomized Complete Block Design (RCBD). Irrigation levels did not significantly influence soil physical properties studied (bulk density, pore volume and particle density). Water stress (application of 70 % CWR) increased root yield, water use efficiency, marketable root yield, jumbo root yield and number of roots per plant as compared to full irrigation while growth of leaves, branches and dry matter content were reduced. Soil amendment significantly improved root and marketable yield better under reduced irrigation (70 % CWR) than under full irrigation. PM, CD and NPK significantly increased marketable yields by 40.96 %, 30.34 % and 21.36 % respectively as compared to the control. Cool chamber evaporative structure (CC) reduced root percentage shrinkage, decay, weight loss and weevil infestation in storage while sprouting increased. Soil amendment significantly reduced percentage root decay. Reduced irrigation increased carotenoid and fibre content while sugar content of roots was decreased. Storage in evaporative cooling structure increased the percentage content of sugar, starch, fat, and phenol of roots while fibre, protein, and ash were reduced after 13 weeks of storage.