C. E. Umebese and A. O. Saba
Abstract
A study was conducted to investigate the agro potential of treated and untreated brewery effluents in the growth of Amaranthus hybridus cultivars VH2 (green), VG2 (red), and HTI (white). Plants were grown in soil amended with untreated (UT) and treated (TT) effluents and at 28, 56 and 84 days after planting, growth parameters were determined using standard procedures. Both effluents contained Ca2+, Mg2+, Cl- , Zn2+, Cu 2+, K+, PO4, NO3 and SO4 but TT had 11-60 % reduction in the concentration of these nutrient elements. Cultivar differences occurred in the growth response of amaranth in the two effluents. Both effluents significantly increased the height of the three cultivars with UT being more effective than TT, corresponding to the higher nutrient content of UT. Furthermore, UT was effective in increasing the leaf area and root biomass of all three cultivars while TT only increased the root biomass of cv.red. TT enhanced the net assimilation rate of cv. red and cv.white while UT enhanced the leaf area ratio of cv.green at the early stage of growth only. Both effluents increased the relative growth rate of cv.white, while only TT enhanced that of cv.red at the early stage of growth. Treated effluent stimulated growth in cv. red while all cultivars responded positively to untreated effluent in various degrees.