Browsing by Subject "Sorghum"

This research was conducted to examine the effect of biochar on drought tolerance and growth of a grain crop. Biochar is a multipurpose charcoal that heals the soil and promotes crop yield. The experiment was part of University of Helsinki biochar research during the summer and autumn of 2011. The effect of biochar was studied in a greenhouse experiment to determine how well it can improve sorghum (Sorghum bicolor Moench) yield. The experimental factors were amount of water given at low, intermediate and full watering levels, and the absence or presence of Acacia-biochar at level of 10 t/ha in the pots of soil used. The number of leaves per plant, leaf surface area, number of panicles, number of grains per panicle, plant and panicle height, root biomass, and whole plant (above ground) biomass was obtained. The plants were grown in a high greenhouse temperature to mimic the Sudanese extreme weather temperature according to the Khartoum Sudan weather forecast at the time of the experiment. The plants got same amount of water from cultivation until the emergence of 5 leaves. Early drought was proposed to determine its effect as the plant move from vegetative to reproductive stage and the effect of biochar on the soil water holding capacity (WHC). The drought stress started at 5 leaf stage of the plant life cycle. The data were analyzed using 2-way analysis of variance (Anova) statistical tools in SPSS (version 20.0, SPSS Inc., Chicago, IL, USA) software. Drought stress affected panicle development, grain yield, plant height, leaf surface area and overall biomass yield. Grain yield and whole plant biomass weight was higher in non-stressed plants. The results indicated no relief to drought stress by biochar addition. In this experiment, the addition of low biochar might be responsible for it inefficiency.

Sorghum (Sorghum bicolor L. Moench) has high contents of phenolic compounds which have both beneficial and antinutritional health effects, including forming insoluble complexes with proteins. This is significant because sorghum has low protein digestibility. Lactic acid bacteria (LAB) fermentation has been found to decrease and modify sorghum phenolic compounds and condensed tannins. The aim of this thesis was to evaluate the effects of LAB fermentation on the phenolic compounds in white and red sorghum using a metabolomics approach. The hypothesis was that fermentation would degrade phenolic compounds into smaller metabolites. Free phenolic compounds were extracted from sorghum using 80% ethanol. The samples were analysed using ultra-performance liquid chromatography coupled with a photodiode-array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-Q-TOF). In order to identify phenolic compounds, both targeted and untargeted metabolomics approaches were used. Multivariate analysis was employed to determine compounds with different abundances between sample groups. The study confirmed the identification of 40 compounds, 37 of which were phenolic compounds, and 23 were distinct between sample groups. Red sorghum contained more flavonoids and condensed tannins compared to white sorghum. Native samples were statistically different from fermented samples, with most changes involving the release of phenolic acids from their conjugated forms and an increase in phenolamines. The metabolomics approach effectively covered the wide range of phenolic compound analysis in sorghum.