PHYSICO-CHEMICAL PROPERTIES AND SENSORY QUALITY OF CASSAVA-COWPEA-MILLET COMPOSITE FLOURS

There is global increase in demand for good health and nutrition. The objective of this study was to formulate nutritious composite flours from cassava ( Manihot esculenta L.) roots, cowpea ( Vigna unguiculata ) leaves, and millet ( Pennisetum glaucum ), especially for children and expectant women. A Nutrisurvey software was used to formulate three flour products, namely 20:50:30, 10:50:40 and 15:60:25 of cassava roots, cowpea leaves, and millet, respectively to achieve more than 40% daily requirement of protein, iron and zinc for the expectant woman. The products were subjected to a sensory panel and evaluated against a standard commercial flour (Famila) sold in the Kenyan market. The flours were also subjected to accelerated shelf-life study based on physico-chemical properties and growth of yeast and molds. Results indicated that 20:50:30 and 10:50:40 had the highest colour scores on a 7-point hedonic scale, 5.2\ub11.35 and 5.2\ub11.48 (P<0.05). The score indicates a near equal acceptability of the flour based on colour for both the standard. The green porridge (15:60:25) was the least accepted flour and had the highest total aerobic count of 3.7 log cfu g-1 after four months of storage. The acid value of the flours ranged from as low as 1.84\ub10.01mg KOH g-1 for the 20:50:30 at day zero and as high as 12.9\ub11.73 mg KOH g-1 after six months of storage. The formulated 20:50:30 flours had protein (8.0%), fat (3.5%) carbohydrates (70%), zinc (0.6 mg100 g-1), iron (0.6 mg100g-1) and vitamin C (0.3 mg100 g-1).Il y a une augmentation mondiale de la demande d\u2019une bonne sant\ue9 et d\u2019une bonne nutrition. L\u2019objectif de cette \ue9tude \ue9tait de formuler des farines composites nutritives \ue0 partir de racines de manioc ( Manihot esculenta L.), de feuilles de ni\ue9b\ue9 ( Vigna unguiculata ) et de mil ( Pennisetum glaucum ), en particulier pour les enfants et les femmes enceintes. Un logiciel Nutrisurvey a \ue9t\ue9 utilis\ue9 pour formuler trois produits \ue0 base de farine, \ue0 savoir 20:50:30, 10:50:40 et 15:60:25 de racines de manioc, de feuilles de ni\ue9b\ue9 et de millet, respectivement, pour atteindre plus de 40% des besoins quotidiens en prot\ue9ines , fer et zinc pour la femme enceinte. Les produits ont \ue9t\ue9 soumis \ue0 un panel sensoriel et \ue9valu\ue9s par rapport \ue0 une farine commerciale standard (Famila) vendue sur le march\ue9 au Kenya. Les farines ont \ue9galement \ue9t\ue9 soumises \ue0 une \ue9tude de dur\ue9e de conservation acc\ue9l\ue9r\ue9e bas\ue9e sur les propri\ue9t\ue9s physicochimiques et la croissance des levures et des moisissures. Les r\ue9sultats ont indiqu\ue9 que 20:50:30 et 10:50:40 avaient le couleur les plus \ue9lev\ue9s sur une \ue9chelle h\ue9donique \ue0 7 points, 5,2 \ub1 1,35 et 5,2 \ub1 1,48 (P <0,05). L\u2018 \ue9chelle h\ue9donique indique une acceptabilit\ue9 presque \ue9gale de la farine sur la base de la couleur pour le standard. La bouillie verte (15:60:25) \ue9tait la farine la moins accept\ue9e et avait le compte a\ue9robie total le plus \ue9lev\ue9 de 3,7 log ufc g-1 apr\ue8s quatre mois de stockage. L\u2019indice d\u2019acide des farines variait entre 1,84 \ub1 0,01 mg KOH g-1 pour le 20:50:30 au jour z\ue9ro et jusqu\u2019\ue0 12,9 \ub1 1,73 mg KOH g-1 apr\ue8s six mois de stockage. Les farines formul\ue9es \ue0 20:50:30 contiennent des prot\ue9ines (8,0%), des lipides (3,5%), des glucides (70%), du zinc (0,6 mg100 g- 1), du fer (0,6 mg100g- 1) et de la vitamine C (0,3 mg100 g- 1)

EFFECTIVE ISOLATION DISTANCE FOR PREVENTION OF CASSAVA VIRUS INFECTIONS IN UGANDA

Cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) are the major viral diseases of cassava in Uganda. Although isolation distance of \u201c50 m\u201d has been recommended by MAAIF in Uganda for prevention of virus infections in crops, the minimum isolation distance has not been verified for effectiveness in cassava. This study assessed the effective isolation distance for management of viral diseases in cassava. Virus-clean cassava cultivars (NASE 03, NASE 14 and NAROCASS 1) from farmers\u2019 fields were used as field sourced (FS) planting materials. Tissue culture (TC) material of the same cultivars were sourced from the National Crops Resources Research Institute and Makerere University Agricultural Research Institute tissue culture laboratories. Both FS and TC materials were tested at isolation distances of 50, 100, 150 and 250 m for virus prevention. The experiment was laid out in a randomised complete block design and was run for 12 months after planting (MAP). Mean CBSD/CMD prevalence significantly varied (P<0.05) among isolation distances in both FS and TC plants, and the 250 m isolation distance was the most effective in reducing disease prevalence. Across cultivars and planting material category at 12 MAP, the 50 m isolation distance had the highest foliar incidence for CBSD (29.2%) and CMD (16.1%); while severity for CBSD was 1.4 and 1.2 for CMD. At 250 m, all FS and TC plants had CBSD/CMD severity of 1.0 and 0% incidence. These results show that 250 m isolation distance can provide an option to disseminate popular, but CBSD/CMD susceptible cassava cultivars thereby manage CBSD/CMD.La maladie des stries brunes du manioc (CBSD) et la maladie de la mosa\uefque du manioc (CMD) sont les principales maladies virales du manioc en Ouganda. Bien qu\u2019une distance d\u2019isolement de \uab50 m\ubb ait \ue9t\ue9 recommand\ue9e par le MAAIF en Ouganda pour la pr\ue9vention des infections virales dans les cultures, l\u2019efficacit\ue9 minimale de la distance d\u2019isolement n\u2019a pas \ue9t\ue9 v\ue9rifi\ue9e dans le manioc. Cette \ue9tude a \ue9valu\ue9 la distance d\u2019isolement efficace pour la gestion des maladies virales dans le manioc. Des cultivars de manioc sans virus (NASE 03, NASE 14 et NAROCASS 1) provenant des champs des agriculteurs ont \ue9t\ue9 utilis\ue9s comme le source de mat\ue9riel de plantation (FS). Le mat\ue9riel de culture tissulaire (TC) des m\ueames cultivars provenait des laboratoires National Crops Resources Research Institute and Makerere University Agricultural Research Institute tissue culture. Les mat\ue9riaux FS et TC ont \ue9t\ue9 test\ue9s \ue0 des distances d\u2019isolement de 50, 100, 150 et 250 m pour la pr\ue9vention des virus. L\u2019exp\ue9rience a \ue9t\ue9 pr\ue9sent\ue9e dans un bloc complet randomis\ue9 et a \ue9t\ue9 r\ue9alis\ue9e pendant 12 mois apr\ue8s la plantation (MAP). La pr\ue9valence moyenne de CBSD / CMD variait significativement (P <0,05) entre les distances d\u2019isolement dans les plantes FS et TC, et la distance d\u2019isolement de 250 m \ue9tait la plus efficace pour r\ue9duire la pr\ue9valence de la maladie. \uc0 travers les cultivars et la cat\ue9gorie de mat\ue9riel de plantation \ue0 12 MAP, la distance d\u2019isolement de 50 m avait l\u2019incidence foliaire la plus \ue9lev\ue9e pour le CBSD (29,2%) et le CMD (16,1%); tandis que la gravit\ue9 pour CBSD \ue9tait de 1,4 et 1,2 pour CMD. \uc0 250 m, toutes les plantes FS et TC avaient une gravit\ue9 CBSD / CMD de 1,0 et une incidence de 0%. Ces r\ue9sultats montrent qu\u2019une distance d\u2019isolement de 250 m peut fournir une option pour diss\ue9miner des cultivars de manioc sensibles au CBSD / CMD, ce qui permet de g\ue9rer le CBSD / CMD

Reaction of selected common bean genotypes to physiological races of Phaeoisariopsis griseola occurring in Kenya

The wide pathogenic variability occurring in Phaeoisariopsis griseola , the causal agent of angular leaf spot of common bean ( Phaseolus vulgaris L.), dictates that new sources of resistance be continuously identified. This study was undertaken to determine the reaction of selected bean genotypes to different races of P. griseola in order to identify potential sources of resistance to angular leaf spot. Selected bean genotypes from Eastern and Central Africa Bean Research Network (ECABREN) and National Dryland Farming Research Centre (NDFRC), Katumani in Kenya were separately inoculated with forty-four races of P. griseola and evaluated for disease development under greenhouse conditions. The genotypes included small- and large-seeded types. None of the genotypes was resistant to all the races, indicating a high complexity of the pathogen population. Thirteen genotypes were resistant (disease score 1 to 3) or moderately resistant (score 4 to 6) to at least 40 of the races. Small-seeded bean genotypes ECAB 0754 and ECAB 0617 were resistant or moderately resistant to all races except Mesoamerican race 33-39 and Afro-Andean race 58-18, respectively. Genotype ECAB 0754 exhibited the highest level of resistance, with an average disease severity of 1.1%. All the resistant or moderately resistant genotypes were of the small-seeded bean types which are commercially less popular. The commonly grown large-seeded genotypes were generally susceptible. Among the bean genotypes evaluated, the small-seeded pintos and browns/yellows possessed high levels of resistance. The results of this study indicate that different bean genotypes have varying levels of resistance to angular leaf spot that can be pyramided into appropriate background to provide durable resistance.Une large variabilit\ue9 pathog\ue9nique du Phaeoisariopsis griseola , l\u2019agent causal de la t\ue2che angulaire de feuilles du haricot commun ( Phaseolus vulgaris L.), sugg\ue8re qu\u2019il y\u2019ait une identification continue de nouvelles sources de r\ue9sistance. Cette \ue9tude \ue9tait entreprise pour d\ue9terminer la r\ue9action des g\ue9notypes de haricot s\ue9lectionn\ue9s aux diff\ue9rentes races de P. griseola afin d\u2019identifier de sources potentielles de r\ue9sistance \ue0 la maladie de t\ue2che angulaire de la feuille. Les g\ue9notypes de haricot fournis par l\u2019Eastern and Central Africa Bean Research Network (ECABREN) et le National Dryland Farming Research Centre (NDFRC), Katumani au Kenya \ue9taient s\ue9par\ue9ment inocul\ue9s avec quarante-quatre races de P. griseola pour l\u2019\ue9valuation en serre du d\ue9veloppement de maladies. Les g\ue9notypes comprenaient de petits et gros grains de semences. Aucune des g\ue9notypes n\u2019\ue9tait r\ue9sistant \ue0 toutes les races de maladies, indicant ainsi une complexit\ue9 \ue9lev\ue9e de la population des pathog\ue8nes. Treize g\ue9notypes \ue9taient r\ue9sistants (\ue9chelle de cotation: 1 \ue0 3) ou mod\ue9r\ue9ment r\ue9sistants (\ue9chelle de cotation: 4 \ue0 6) sur au moins quarante de toutes les races. Les g\ue9notypes de haricot \ue0 petits grains ECAB 0754 et ECAB 0617 \ue9taient r\ue9sistants ou mod\ue9r\ue9ment r\ue9sistants \ue0 toutes les races \ue0 l\u2019exception de Mesoamerican race 33-39 et Afro-Andean race 58-18, respectivement. Le G\ue9notype ECAB 0754 avait manifest\ue9 un niveau \ue9lev\ue9 de r\ue9sistance, avec un taux moyen de s\ue9verit\ue9 de 1.1%. Tous les g\ue9notypes r\ue9sistants ou mod\ue9r\ue9ment r\ue9sistants \ue9taient de ceux \ue0 petits grains commercialement moins populaires. Les g\ue9notypes \ue0 gros grains commun\ue9ment cultiv\ue9s \ue9taient g\ue9n\ue9ralement susceptibles. Parmi les g\ue9notypes \ue9valu\ue9s, ceux \ue0 petits grains "pintos" et bruns/jaunes \ue9taient dot\ue9s des niveaux \ue9lev\ue9s de r\ue9sistance. Les r\ue9sultats de cette \ue9tude montrent que diff\ue9rents g\ue9notypes de haricot poss\ue8dent de niveaux diff\ue9rents de r\ue9sistance \ue0 la maladie de t\ue2che angulaire de la feuille pouvant \ueatre combin\ue9s par pyramidage pour d\ue9velopper une vari\ue9t\ue9 de haricot \ue0 r\ue9sistance durable