Effect of Biochar and Inorganic Fertilizer on Soil Biochemical Properties in Njoro Sub-County, Nakuru County, Kenya

Declining soil fertility is a major constraint to potato farming, the second most important food crop in Kenya. The objective of the study was to determine the effect of different rates of biochar and inorganic fertilizer on some soil properties;soil pH, soil phosphomonoesterases, inorganic nitrogen and extractable phosphorus. The study was conducted for two seasons (short and long rains) at two locations (Egerton University agricultural field and farmer’s field in Mau Narok) using a split-plot design in a randomized complete block (RCBD) arrangement with variety as the main plot and soil amendments as the subplot. Biochar and Diammonium Phosphate (DAP) at 0, 5, and 10 t⋅ha−1 and 0, 250, and 500 kg⋅ha−1 respectively, were applied, resulting in nine treatment combinations. Two potato varieties (Shangi and Destiny) were used in the study. A combination of 5 t⋅ha−1 biochar and 500 kg⋅ha−1 DAP and sole application of biochar at 5 t⋅ha−1 resulted in an increase of 1.25, 2.54 units in soil pH in two seasons, respectively. Similarly, a combination of 5 t⋅ha−1 biochar and 250 kg⋅ha−1 DAP increased soil available phosphorus by 105 units from 30.7 mg⋅kg−1 to 136 mg⋅kg−1. The application rate of 5 t⋅ha−1 biochar with 250 or 500 kg⋅ha−1 DAP significantly increased soil nitrate by 102.11 and 116.14 units, respectively. Soils amended with biochar at 5 t⋅ha−1 combined with 500 kg⋅ha−1 DAP, 10 t⋅ha−1 of biochar combined with either 250 kg or 500 kg of DAP gave the highest alkaline enzymes (mM pNP × kg−1 × h−1). However, the highest acid soil phosphomonoesterases were obtained under the sole application of DAP at 500 ha−1. Thus, using biochar with chemical fertilizer seems a plausible option to ameliorate the declining nutrient base of farmland in Kenya, which could sustainably support potato growth.

Biochemical changes in phenols,flavonoids,tannins,vitamin E,β-carotene and antioxidant activity during soaking of three white sorghum varieties

Objective:To investigate the changes in total phenols,flavonoids,tannins,vitamin E, β-carotene and antioxidant activity during soaking of three white sorghum varieties.Methods: The changes in total phenols,total ilavonoids,tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity during soaking of sorghum grains were determined.Results:Total phenols,total flavonoids,tannins,vitamin E,P-carotene and antioxidant activity in raw sorghum were ranged from 109.21 to 116.70,45.91 to 54.69,1.39 to 21.79 mg/100 g,1.74 to 5.25,0.54 to 1.19 mg/kg and 21.72%to 27.69%and 25.29%to 31.97%,respectively. The above measured compounds were significantly decreased after soaking.p-Hydroxybenzoic acid,vanillic acid,syringic acid and cinnamic acid represent the major phenolic acids in Dorado variety.While ferulic acid,p-coumaric acid,gallic acid and caffeic acid represent the major phenolic acids in Shandaweel-6.On the other hand,protocatechuic acid represents the major phenolic acids in Giza-15.Regarding flavonoids components,Dorado was the highest variety in kampferol and naringenin while Shandaweel-6 was the highest variety in luteolin, apigenin,hypersoid,quercelin and christen.Finally,Giza-15 was the highest variety in catechin. Phenolic acids,flavonoid compounds and antioxidant activities were decreased after soaking. Conclusions:Sorghum varieties have moderate quantities from total phenols,total flavonoids, tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity which decreased after soaking.

Physiochemical, Nutritional and Technological Properties of Instant Porridge Supplemented with Mung Bean

The present study was undertaken to prepare instant porridge from some useful and available ingredients such as bulgur powder, potato, tomato, carrot, mung bean (unsoaked, soaked and germinated), then seasoned with onion, garlic, salt, black pepper, cumin and coriander to make B1, B2 and B3 formulas. Chemical, physical properties, amino acids and sensory evaluation of instant porridge formulas were determined. The data showed that B2 formula which contained soaked mung bean had the highest calories value, total essential amino acids, biological value and water absorption index (WAI) compared to the other formulas, also it is recorded the highest degree of lightness L* values (82.39 and 56.65), least redness a* values (0.98 and 1.45) and intermediate in yellowness b* values (25.91 and 24.45) before and after rehydrated, respectively. Regarding to sensory evaluation, there was a significant increase in color, taste and overall acceptability in B2 compared to the other formulas. Based on these results, revealed that the soaked mung bean was a good source of essential amino acid and calories to enhance nutritional and technological quality of the resultant porridge.

Effect of Blending Doum (<i>Hyphaene thebaica</i>) Powder with Wheat Flour on the Nutritional Value and Quality of Cake

Pastry is an essential part of food stuff people like, especially preferring those made of wheat flour: cakes, biscuits, pancakes, etc. The nutritive value of the products mentioned above is not high. Therefore, there is a need to increase it by adding something like doum fruit (Hyphaene thebaica L.), which is a widespread in Upper Egypt. Doum fruit is a rich source of fibers and antioxidants, also other valuable substances such as carbohydrates and minerals especially potassium (K for people suffering from blood pressure problems). This investigation was carried out to study the possibility of utilization doum fruit powder in cake production. Five levels of wheat flour substitution were used 0%, 5%, 10%, 15% and 20% to produce cake. Also, the effects of blends on farinograph parameters were studied. Results indicated that substitution of doum powder (D.P) led to increase the water absorption (%) and dough weakening (B.U), whereas dough stability (min) was decreased. The water holding capacity of blends increased with increasing the level of substitution. The chemical, physical and sensory characteristics of the prepared cakes were studied. Results showed that increasing the levels of substitution increased the total fat, crude fiber and ash contents in produced cake compared with control. Minerals of the produced cake showed an increment in K and Mg, while slightly increment in Ca, Fe and Zn with increasing the level of substitution. Total phenol and antioxidant activity (AO) increased in substituted cake. Physical attributes of the produced cakes were evaluated and results showed that volume of substituted cakes decreased with increasing the level of replacement except for 10% level it increased. Results of textural analysis showed that D.P fiber decreased all the parameters. Concerning cake color, as the percentage of D.P increased, the color of the cake became darker and had high a and b values. The sensory evaluation results showed an insignificantly decrease in the acceptability by increasing the doum powder substitution comparing with control.

Biofumigation Efficacy of Spider Plant (Cleome gynandra L.) Accessions on Nematode Control in Tuberose (Polianthes tuberosa L.)

Tuberose(Polianthes tuberosa L.)is a perennial summer flower grown by smallholders in Kenya for export.However,its production and export volumes have declined drastically due to nematodes infestation.This study evaluated the effect of Cleome gynandra accessions on nematode management on tuberose.Experiment was carried out at Egerton University,Kenya using a randomized complete block design with four replications.The treatments were C.gynandra namely“Simlaw”,“Egerton”,“Taastrup”,“PS”and“IP8”,applied at 6 kg/m^(2) and compared with Brassica napus,solarization and untreated control.Data was collected on growth and yield parameters,nematode infestation and quality of tuberose.Data collected was subjected to analysis of variance at p≤0.05 and means separated using Tukey’s test.Biofumigation with Cleome gynandra accessions helped to reduce nematode population by 34%,gall numbers by 83% and galling index by 96%when compared with the control.Use of biofumigation helped to improve plant height and leaf number of tuberoses by 16% and 87%,respectively,when compared with the control.Use of biofumigation helped to improve spike length by 32%,marketable spikes by 80%,and flower yield by 90% and reduced nonmarketable spikes by 95% when compared with the control.Based on the above results,use of Cleome gynandra accessions and other biofumigants such as rape seed can be used to manage nematodes and improve growth,yield and quality of tuberose.

Preparation of Dried Vegetarian Soup Supplemented with Some Legumes

The present work was aimed to prepare dried vegetarian soup supplemented with some legumes. Potatoes, hull-less barley flour, carrot, tomatoes, onion, garlic, salt, black pepper, coriander and cumin (served as F1) were used in combination with lentil, green pea and chickpea to formulate F2, F3, and F4, respectively. Chemical, physical, rheological and sensory evaluation was performed. The results indicated that supplementation with legumes significantly enhanced the nutritional characteristics, where the dried vegetarian soup mixtures had reasonable amounts of the required nutrients particularly, protein, carbohydrates, fats, Fe and Zn with good in vitro protein digestibility and mineral availability. Moisture content and water activity predicted the extended shelf-life and stability of the dried soup mixtures. The four resultant soup samples F1, F2, F3 and F4 had a noticeable viscosity pattern characterized by a non-Newtonian pseudoplastic flow behavior. Supplementation with legumes significantly (p ≤ 0.05) affects taste, color, flavor attributes and overall acceptability of the resultant soup samples. But, it had no significant effect on thickness and appearance. The results clearly demonstrated the usefulness of supplementing the dried vegetarian soup mixtures with legumes to enhance nutritional and technological quality of the resultant soup and lentil was the most valuable addition with the highest acceptability.

Evaluation Quality of One Layer Flat Bread Supplemented with Beans and Sorghum Baked on Hot Metal Surface

The present study was carried out to develop the wheat flour nutritional value with good quality of unleavened bread by adding 5%, 10% and 15% of bean or sorghum flour. Water absorption was increased by addition of bean flour as a result of increase rate of substitution. Dough stability decreased for bean and sorghum blends as the same as increasing addition. Softening gradually increased with increasing the addition of beans or sorghum. Addition of 15% sorghum had the highest degree of softening compared with wheat control and beans mixtures. The extensibility, elasticity and the energy of produced dough were decreased with addition of beans or sorghum to wheat flour and the reduction increased with increasing the level of substitution. In contrast, addition of beans or sorghum to wheat flour increased the proportional number of the produced dough from 3.25 to 3.62 and from 1.80 to 2.90 for beans and sorghum dough, respectively. Bread supplemented with beans had the highest values in protein, ash and fiber compared with wheat and sorghum bread whereas, bread supplemented with sorghum had the highest values in fat content compared with wheat and beans bread. Sorghum bread had the highest iron and zinc content while beans bread had the highest calcium content. The sensory evaluation showed that different blends of beans and sorghum bread had highly acceptable values of all characteristics comparing with wheat control bread. Freshness of all unleavened flat bread blends decreased at different periods as well as bread control compared with zero time period. Water holding capacity (WHC) was significantly increased in all samples compared with wheat bread. Supplementation of bread with 15% beans recorded the highest value in WHC.

Yield Evaluation of a Wheat Line with Combined Resistance to Russian Wheat Aphid and Stem Rust Race “Ug99” in Kenya

InKenya, Russian wheat aphid (RWA) and stem rust race TTKS (“Ug99”) are the most devastating pests of wheat. Severe infestations by RWA result in yield losses of up to 90% while epidemics of “Ug99”can cause up to 100% loss. The two pests combined have seriously affected farmer incomes forcing them to rely heavily on pesticides and increasing the cost of production. This study sought to evaluate a wheat line that has been developed to be resistant to both RWA and “Ug99”by pyramiding two major resistance genes. Three varieties were used in this study: “Kwale”, a Kenyan high yielding commercial variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line resistant to RWA but with poor agronomic attributes. The F1 of the double cross (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99”resistance. The surviving DC F1 progenies were left to self pollinate in the field to obtain the DC F2. The DC F2 progenies were sequentially screened against RWA and “Ug99”to obtain a resistant population to both RWA and “Ug99”. The yield and yield components of the new resistant line were compared with the three parents. Results showed that the DC F2:3 had higher yields than the three parents based on 1000 kernel weight, weight of kernel per spike, and the actual yield in tons/ha, indicating that the genes were successfully introgressed. It is concluded that though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99”and can be used as a component for “Ug99”resistance breeding together with other Sr genes.

The Potential Effect of Special Formulas on Cirrhotic Rats

Liver protective effect of special formulas (1 and 2) was assessed against carbon tetra chloride (CCl4) which induced liver damage in Wister albino rats. The two prepared formulas reduced the changes in body weight and liver weight caused by CCl4 in rats. The toxicity of CCl4 is related to loss in body weight and increase in liver weight in rats. The weight ratios of liver to body weight (LW/BW) significantly increased in rats treated with CCl4 followed by other groups. Formulas 1 and 2 could play an important role in improvement of hematological indices in liver cirrhosis rats. Feeding treated rats on special formulas showed improvement in liver function compared to rats fed on basal diet, reflected by significant reduction of the activity of transaminases (ALT and AST), alkaline phosphatase (ALP) and total bilirubin. There was a significant increase in total protein, albumin and globulin in serum. Significant increase in liver weight in rats treated with CCl4. There are no histopathological changes in all groups under study except for group 4 (CCl4 treated rats fed on basal diet) which orally administrated with CCl4 and had congestion of central vein and hepatic sinusoids.

Development and Characterization of Wheat Germplasm with Combined Resistance to Russian Wheat Aphid and Stem Rust (Race “Ug99”) in Kenya

Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses. Of the biotic stresses a devastating pest (Russian wheat aphid (RWA)) and a serious disease (stem rust race TTKS (“Ug99”)) are currently the biggest problem for wheat producers in Kenya. Severe infestations by RWA may result in yield losses of up to 90% while “Ug99” infected fields may suffer 100% crop loss. The two pests combined are seriously affecting wheat farmers’ incomes because of the heavy reliance on pesticides that increase the cost of production. This study attempted to develop and characterize wheat lines that are resistant to both RWA and “Ug99” by pyramiding two major resistance genes. Three wheat varieties: “Kwale”, a Kenyan high yielding variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line with resistance to RWA but of poor agronomic attributes were used. A double cross F1 (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99” resistance. Surviving DC F1 progenies were left to self pollinate to obtain the F2 of the double cross (DC F2). The DC F2 progenies were sequentially screened against RWA and “Ug99” to yield a population that was resistant to both RWA and “Ug99”. Genotyping of the DC F2:3 families were conducted to select homozygous resistant plants. Data indicated that the RWA and “Ug99” resistance genes were successfully pyramided. Though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99” and can still be effectively used as a component for “Ug99” resistance breeding together with other Sr genes.

Zai Pit Effects on Selected Soil Properties and Cowpea (<i>Vigna unguiculata</i>) Growth and Grain Yield in Two Selected Dryland Regions of Kenya

Erratic rainfall and temperature regimes, strongly affect agricultural productivity. To address the reduction in production, this study assessed the effect of Zai pit depths on selected soil properties and cowpea growth and grain yield. “Zai” pit technology was tested in two locations falling under Agroecological Zone IV (relatively dry areas) i.e. Katumani in Machakos County and Naivasha in Nakuru County, Kenya, aiming to determine the combined effect of four “Zai” pit depths and two levels of manure (plots with manure and plots without manure) on selected soil properties, growth and yield of cowpea. Experiment was laid out in split plot arrangement, with manure levels as the main plot factor and “Zai” pit depths (Flat: Z0, 30 cm: Z30, 45 cm: Z45 and 60 cm: Z60) as subplot factor, replicated four times. Cowpea (M66 variety) was used as the test crop. Inorganic N and extractable P were significantly (P < 0.05) higher, at 1.37 mg⋅kg−1 for Nin and 80.4 mg⋅kg−1 for Pex in Zai pits compared to flat plots which were at 0.91 mg⋅kg−1 for Nin and 47.1 mg⋅kg−1 for Pex. The values of Nin and Pex also varied depending on depths, with Z45 having highest Nin at 1.17 against the least, at 0.89 in the Z0, while Pex was highest in Z30 at 102.3 mg⋅kg−1 while Z0 having the least Pex of 89.7 mg⋅kg−1. Generally, crops in “Zai” pitted plots were larger in diameter at 0.46 cm than crops in flat plots at 0.42 cm. Better performance was observed in yield, with Z30 yielding 30.5% against 18.2% Flat plots in Machakos while 27.9% in Z30 against 22.5% from Flat plots in Naivasha. This study demonstrated great potential of “Zai” pit technology on crop production, as reflected on improved growth and yield of cowpeas. Combining “Zai” pits with manure increases soil Nin, Pex and is a guarantee of great crop performance in terms of high final yields.

Evaluation of Potential Fodder Sorghum Genotypes for Prussic Acid,Lignin and Cellulose Content

Sorghum is a potential fodder crop for an alternative source of livestock feed in Kenya.A study was done to determine the levels of prussic acid,lignin and cellulose content in potential fodder sorghum varieties at Egerton University Field Station in Kenya.Twenty-five sorghum genotypes were grown in a randomized complete block design(RCBD)and replicated three times.The genotypes were sampled at 3-leaf stage and analyzed for prussic acid,lignin and cellulose.The data were subjected to statistical analysis of variance and correlation using Statistical Analysis System(SAS)program version 9.1.Prussic acid levels were significantly different even at an early stage,with local varieties producing more.Lignin and cellulose had an inverse relationship with respect to concentration.Fodder sorghum genotypes varied significantly in prussic acid,lignin and cellulose,even at an early growth stage.

Adaptability and Phenotypic Stability of Resistance to Two Viral Diseases and Yield Traits in Cassava

Cassava productivity is hampered by pests and diseases including cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). The main objective of this study was to identify stable superior genotypes that combine disease resistance and high yield. Sixteen cassava genotypes were planted in a randomized complete block design with three replications for six planting seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (P < 0.001) effects of genotype, environment, and genotype-by-environment (G*E) interactions were observed for all traits studied. Percent sum of squares (SS) due to environment (12.66% - 85.23%) was the highest followed by G*E (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) was highest followed by G*E (26.14% - 35.91%) for CBSD foliar and root symptoms indicating that the environment and G*E greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.

Sources of Resistance to Blast Disease(Pyricularia grisea L.)in Finger Millet(Eleusine Coracana)Germplasm

Blast has been a continuous threat to finger millet production in semi-arid tropics.The disease is economically important and widespread in finger millet major growing areas of western,Nyanza and Rift valley in Kenya.Host resistance is the most economical and effective means of controlling the disease as finger millet is grown by resource-poor farmers.This study evaluated a hundred finger millet genotypes for resistance to blast at KALRO(Kenya Agricultural Research and Livestock Organization)Kakamega and Alupe,Kenya for two seasons in 2011/2012 in a lattice square design for two seasons each.Data on blast incidence and severity were measured.Data were analyzed using ANOVA(analysis of variance)and means separated using Duncan multiple range test(DMRT)at p<0.005.The results showed that disease severity was highest in early maturing varieties and lowest in the late maturing varieties.The most resistant genotypes were:GBK000702,GBK000513,GBK029869,GULU-E,GBK000752 and Busibwabo.Pearson correlation analysis between neck severity and physiological maturity was positively significant(r=-0.47).A strong positive correlation between finger severity and neck severity(r=0.87)was observed.These tolerant genotypes could be utilized as donor parents for breeding durable blast resistant varieties.

Effects of Cinnamaldehyde, Ocimene, Camphene, Curcumin and Farnesene on Candida albicans

Efficacy of five plant molecules against thirty three clinical isolates and two standard strains of C. albicans, differentially susceptible to fluconazole (FLC) is tested in this study. Effect on biofilm (adhesion, development and maturation) formation, morphogenesis and synergy with fluconazole (FLC) against a FLC resistant strain of Candida albicans ATCC 10231 is also evaluated. All the plant molecules tested were equally effective against isolates and strains of C. albicans (N = 35) tested in this study. Cinnamaldehyde was found most effective against planktonic growth followed by ocimene. Both the molecules exhibited fungicidal activity and killed 99.9% of inoculum within 80 and 20 min of exposure respectively at 0.62 mM and 176.8 mM concentrations. Curcumin (5 - 20 mM), camphene (8 - 32 mM) and farnesene (25 - 100 mM), although inhibited planktonic growth, were fungistatic. All the five plant molecules tested in this study inhibited morphogenesis significantly and exhibited considerable activity against biofilm formation. Inhibition of biofilm was found to be stage specific i.e. efficacy was more against adhesion followed by developing and mature biofilm. Plant molecules tested exhibited excellent synergy with fluconazole. However FIC index values 0.155, 0.062 and 0.046 indicate that ocimene was the most effective synergistic molecule inhibited planktonic growth, developing biofilm and mature biofilm growth respectively at very low concentrations. This is the first report of anti-Candida activity of three terpenoids viz. ocimene, farnesene and camphene against planktonic & biofilm growth, morphogenesis as well as synergy with FLC. Plant molecules tested in this study may find use in antifungal chemotherapy individually and or in a combination with FLC.