Determination of the heterotic groups of maize inbred lines and the inheritance of their resistance to the maize weevil

Maize weevil ( Sitophilus zeamais Motschulsky) is a major maize ( Zea mays L) storage insect pest in the tropics. Fifty-two inbred lines developed for weevil resistance were crossed to two testers, A and B, to determine their heterotic groups and inheritance of resistance to maize weevil. For 10 testcrosses selected for performance by tester, the correspondent testcrosses onto the opposite tester and all the parents involved in those crosses, were included in the combining study. Of 52 inbred lines, 7 had significantly positive general combining ability (GCA) for yield, with a maximum GCA effect of 1.24t.ha-1. Based on the specific combining ability (SCA) effect, 23 inbred lines were assigned to heterotic Group A, 24 to Group B, and 5 to both A and B. The combining ability test for weevil resistance revealed that only one inbred, WL118-9, was classified as moderately resistant with a susceptibility index (SI=5.4), two lines were moderately susceptible; and the remaining inbreds were susceptible to highly susceptible to the maize weevil. Additive and non-additive gene action were important for yield, but for weevil resistance, additive gene action was more important. Weevil resistance exists and is moderately heritable.Le charan\ue7on du ma\uefs ( Sitophilus zeamais Motschulsky) est un plus grand ravageur du ma\uefs ( Zea mays L) dans les tropiques. Cinquante-deux lign\ue9es d\ue9velopp\ue9es pour la r\ue9sistance au charan\ue7on du ma\uefs \ue9taient crois\ue9es aux testeurs A et B afin de d\ue9terminer leurs groupes h\ue9t\ue9rotiques ainsi que la transmission de la r\ue9sistance au charan\ue7on du ma\uefs. Pour dix lign\ue9es s\ue9lectionn\ue9es pour test de performance par le testeur, les croisements correspondants au testeur oppos\ue9 ainsi que tous les parents impliqu\ue9s dans le croisement \ue9taient inclus dans l\u2019 \ue9tude d\u2019aptitude. Parmi les 52 lign\ue9es, 7 avaient significativement montr\ue9 une positive Aptitude G\ue9n\ue9rale \ue0 la combinaison (GCA) pour le rendement, avec un effet maximum GCA de 1.24 t ha-1. Bas\ue9 sur l\u2019 Aptitude Sp\ue9cifique \ue0 la Combinaison (SCA), 23 lign\ue9es ont \ue9t\ue9 attribu\ue9es au groupe h\ue9t\ue9rotique A, 24 au groupe B et 5 aux deux groupes h\ue9t\ue9rotiques A et B. Le test d\u2019aptitude \ue0 la r\ue9sistance au charan\ue7on a r\ue9v\ue9l\ue9e q\u2019une seule lign\ue9e, WL118-9 \ue9tait classifi\ue9e comme mod\ue9r\ue9ment r\ue9sistante avec un index de susceptibilit\ue9 de 5.4, deux lign\ue9es \ue9taient mod\ue9r\ue9ment susceptibles tandis que les lign\ue9es restantes \ue9taient soit susceptibles ou hautement susceptibles au charan\ue7on du ma\uefs. L\u2019action additive et non additive des g\ue8nes \ue9taient tr\ue8s importante. Les g\ue8nes de r\ue9sistance au charan\ue7on du ma\uefs existent et sont mod\ue9r\ue9ment transmissibles \ue0 la descendance

Potential for yield loss reduction and profitability assessment of pesticide control of groundnut leaf miner among soybean genotypes

Groundnut leaf miner (GLM) is currently a threat to soybean production in Uganda due to the great yield losses as a result of the severe damage it causes on leaves leading to reduced photosynthetic area. GLM is a fairly new pest on soybean in Uganda, having initially been observed in soybean fields in 2011 in eastern Uganda. The objective of this study was to determine the yield loss caused by the groundnut leaf miner and effectiveness and profitability of commonly used pesticides for the control of the groundnut leaf miner ( Aproaerema modicella Deventer) (GLM), when tested with popular soybean ( Glycine max ) genotypes grown in Uganda. In a split plot RCBD design, pesticide protection (treated vs. untreated) formed the main plots; and six commercial soybean varieties (Maksoy 1N, 2N, 3N, 4N, 5N; and Namsoy 4M) as subplots. The study was done in two locations in eastern Uganda (Iki Iki District Agricultural Training and Information Centre (Iki Iki DATIC) and National Semi-Arid Resources Research Institute, Serere (NaSARRI) with two planting rounds at Iki Iki. These sites were chosen because they are hot spots for GLM. GLM severity and soybean yield were significantly affected by the pesticide protection. Overall, percentage grain yield losses caused by GLM on the different soybean varieties ranged from 37.3% to 65.7% and the highest loss was displayed by Maksoy 5N. Grain yield loss recorded at Iki Iki DATIC (53.1%) was remarkably higher than that recorded at the NaSARRI (49.1%). Economic analysis showed marginal returns to be dependent on location, with the Iki Iki DATIC having 0.6 and NaSARRI 1.1. This study has shown that the groundnut leaf miner, a recently emergent pest of soybean is becoming a big threat to soybean production and that chemical control alone may not be economical in managing the pest.La mineuse de feuilles d\u2019arachide (MFA) constitue actuellement une menace pour la production de soja en Ouganda en raison des pertes de rendement consid\ue9rables dues aux d\ue9g\ue2ts importants caus\ue9s aux feuilles, ce qui a entra\ueen\ue9 une r\ue9duction de la surface photosynth\ue9tique. Le MFA est un ravageur relativement nouveau sur le soja en Ouganda. Il avait d\u2019abord \ue9t\ue9 observ\ue9 dans des champs de soja en 2011 dans l\u2019est de l\u2019Ouganda. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer la perte de rendement caus\ue9e par la mineuse de feuilles d\u2019arachide et l\u2019efficacit\ue9 et la rentabilit\ue9 des pesticides couramment utilis\ue9s pour lutter contre la mineuse de feuilles d\u2019arachide ( Aproaerema modicella Deventer) (MFA), lorsqu\u2019il \ue9tait test\ue9 avec du soja tr\ue8s r\ue9pandu ( Glycine max ) g\ue9notypes cultiv\ue9s en Ouganda. L\u2019essai a \ue9t\ue9 install\ue9 suivant un dispositif split plot en parcelles divis\ue9es, la protection antiparasitaire (trait\ue9e ou non trait\ue9e) constituait les parcelles principales; et six vari\ue9t\ue9s commerciales de soja (Maksoy 1N, 2N, 3N, 4N, 5N; et Namsoy 4M) en sous-parcelles. L\u2019\ue9tude a \ue9t\ue9 r\ue9alis\ue9e dans deux regions de l\u2019est de l\u2019Ouganda (Centre de formation et d\u2019information agricoles du district d\u2019Iki Iki (Iki Iki DATIC) et Institut national de recherche sur les ressources semi-arides de Serere (NaSARRI), avec deux fois de plantation \ue0 Iki Iki. Ces sites ont \ue9t\ue9 choisis parceque ce sont des regions tr\ue8s menaces par MFA. La protection contre les pesticides a eu un effet important sur la s\ue9v\ue9rit\ue9 du MFA et le rendement du soja. Generalement, le pourcentage de pertes de rendement en grain caus\ue9es par la sur les diff\ue9rentes vari\ue9t\ue9s de soja variait de 37,3% \ue0 65,7% et la perte la plus \ue9lev\ue9e a \ue9t\ue9 montr\ue9e par Maksoy 5N. La perte de rendement en grains trouv\ue9e \ue0 Iki Iki DATIC (53,1%) \ue9tait remarquablement sup\ue9rieure \ue0 celle trouv\ue9e \ue0 NaSARRI (49,1%). L\u2019analyse \ue9conomique a montr\ue9 que les rendements marginaux d\ue9pendaient de la localisation, l\u2019Iki Iki DATIC \ue9tant \ue0 0,6 et NaSARRI \ue0 1,1. Une \ue9tude a montr\ue9 que la mineuse de feuilles d\u2019arachide, un ravageur du soja r\ue9cemment apparu, constituait une menace majeure pour la production de soja et que la lutte chimique \ue0 elle seule pouvait ne pas \ueatre rentable pour lutter contre ce ravageur

EFFECT OF TEMPERATURE AND CASSAVA GENOTYPE ON THE DEVELOPMENT, FECUNDITY AND REPRODUCTION OF Bemisia tabaci SSA1

The Bemisia tabaci complex is currently recognised as key agricultural pests that cause economic damage globally. Temperature is the most important driver of changes in behaviour, abundance and distribution of insect pests, including the whitefly (Bemisia tabaci). The objective of this study was to evaluate the development, fecundity and reproduction of B. tabaci SSA1 on cassava genotypes under a range of temperatures. A laboratory study was conducted using three cassava genotypes (Alado alado, NAROCASS 1 and NASE 14) at five constant temperatures (16, 20, 24, 28 and 32 \ub0C). The parameters assessed included development duration, survival, fecundity and population parameters for B. tabaci SSA1. Temperature had significant effects (P<0.001) on development time, survival and fecundity of B. tabaci; while cassava genotype had no effect (P>0.05). An inverse relationship was observed between development time and temperature for all stages across all cassava genotypes. The total life cycle was 63.8 days at 16 \ub0C and 17.9 days at 32 \ub0C on NAROCASS 1. Survival for each stage throughout the entire life cycle increased with temperature and was highest at 32 \ub0C, although this was not significantly different from that at 28 \ub0C. Fecundity increased with temperature and was highest at 32 \ub0C on all cassava genotypes. For all cassava genotypes, the intrinsic rate of increase (rm), finite rate of increase (\u3bb) and net reproductive rate (Ro) increased with temperature, while mean generation time (T) reduced following a similar pattern. At 32 \ub0C, rm, Ro, \u3bb and T were 0.2, 48.7, 1.2 and 22.6 days, respectively; compared to 0.01, 1.9, 1.0 and 71.2 days at 16 \ub0C on Alado alado. Therefore, the ideal development temperature for B. tabaci SSA1 is 32 \ub0C. Thus, there is a risk of accelerated future expansion of B. tabaci SSA1 populations globally, with global warming and climate variability.Le complexe Bemisia tabaci est actuellement reconnu comme un ravageur agricole cl\ue9 causant des dommages \ue9conomiques \ue0 l\u2019\ue9chelle mondiale. La temp\ue9rature est le facteur le plus important des changements de comportement, d\u2019abondance et de r\ue9partition des insectes ravageurs, y compris l\u2019aleurode (Bemisia tabaci). L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer le d\ue9veloppement, la f\ue9condit\ue9 et la reproduction de B. tabaci SSA1 sur des g\ue9notypes de manioc sous une gamme de temp\ue9ratures. Une \ue9tude en laboratoire a \ue9t\ue9 men\ue9e en utilisant trois g\ue9notypes de manioc (Alado alado, NAROCASS 1 et NASE 14) \ue0 cinq temp\ue9ratures constantes (16, 20, 24, 28 et 32 \ub0C). Les param\ue8tres \ue9valu\ue9s comprenaient la dur\ue9e du d\ue9veloppement, la survie, la f\ue9condit\ue9 et les param\ue8tres de population pour B. tabaci SSA1. La temp\ue9rature a eu des effets significatifs (P<0,001) sur le temps de d\ue9veloppement, la survie et la f\ue9condit\ue9 de B. tabaci, tandis que le g\ue9notype du manioc n\u2019a eu aucun effet (p>0,05). Une relation inverse a \ue9t\ue9 observ\ue9e entre le temps de d\ue9veloppement et la temp\ue9rature pour tous les stades dans tous les g\ue9notypes de manioc. Le cycle de vie total \ue9tait de 63,8 jours \ue0 16 \ub0C et de 17,9 jours \ue0 32 \ub0C sur NAROCASS 1. La survie pour chaque \ue9tape tout au long du cycle de vie entier augmentait avec la temp\ue9rature et \ue9tait maximale \ue0 32 \ub0C. Cependant, la survie \ue0 28 \ub0C n\u2019\ue9tait pas significativement diff\ue9rente de celle observ\ue9e \ue0 32 \ub0C. La f\ue9condit\ue9 augmentait avec la temp\ue9rature et \ue9tait maximale \ue0 32 \ub0C sur tous les g\ue9notypes de manioc. Pour tous les g\ue9notypes de manioc, le taux d\u2019accroissement intrins\ue8que (rm), le taux d\u2019accroissement fini (\u3bb) et le taux net de reproduction (Ro) ont augment\ue9 avec la temp\ue9rature, tandis que le temps de g\ue9n\ue9ration moyen (T) a diminu\ue9 selon un sch\ue9ma similaire. A 32 \ub0C, rm, Ro, \u3bb et T \ue9taient respectivement de 0,2, 48,7, 1,2 et 22,6 jours ; contre 0,01, 1,9, 1,0 et 71,2 jours \ue0 16 \ub0C sur Alado alado. Par cons\ue9quent, d\u2019apr\ue8s cette \ue9tude, la temp\ue9rature de d\ue9veloppement id\ue9ale pour B. tabaci SSA1 est de 32 \ub0C. Ainsi, il existe un risque d\u2019expansion future acc\ue9l\ue9r\ue9e des populations de B. tabaci SSA1 \ue0 l\u2019\ue9chelle mondiale, avec le r\ue9chauffement climatique et la variabilit\ue9 climatique

STABILITY AND EXTENT OF RESISTANCE OF COWPEA LINES TO FLOWER BUD THRIPS IN UGANDA

Cowpea ( Vigna unguiculata (L.) Walp.) is a legume attacked by several field insect pests, with flower thrips ( Megalurothrips sjostedti Trybom) being the most damaging. It causes 20 to 100% yield losses. Cowpea constitutes an important source of protein for resource poor households in Africa. The objective of this study was to identify cowpea lines that are resistant to flower thrips as a step in developing sustainable thrips management strategies. Seventy two cowpea cultivars were screened in three locations and two rainy seasons in Uganda, for thrips damage and yield components. Up to 11 cultivars (IT2841*Brown (1.50), MU20B (1.58), EBELAT*NE39 (1.61), WC17 (1.63), WC29 (1.65), MU24C (1.65), WC5 (1.66), NE46 (1.67), WC30 (1.68), NE67 (1.69), and NE51 (1.71)) were the most resistant and stable across locations. However, thrips damage was negatively correlated with the number of days to flowering (r = -0.32), indicating that the resistance in the cultivars was explained by the flower thrips infestation escape due to later flowering. Cultivar MU9 was high yielding (813.87 kg ha-1) and the most adapted genotype to all the locations; while cultivars WC26, NE48, and NE5 were the most adapted to Arua and Serere, and WC48A was the most adapted to Makerere University Agricultural Research Institute, Kabanyolo (MUARIK). There is potential of finding resistance sources in the cultivars tested.Le ni\ue9b\ue9 ( Vigna unguiculata (L.) Walp.) est une l\ue9gumineuse attaqu\ue9e par plusieurs insectes au champ avec thrips ( Megalurothrips sjostedti Trybom) le plus nuisible causant 20-100% de perte de rendement. Le ni\ue9b\ue9 constitue une source de prot\ue9ine bon-march\ue9 pour beaucoup de pauvres m\ue9nages en Afrique. L\u2019objectif de cette \ue9tude \ue9tait d\u2019identifier des vari\ue9t\ue9s plus r\ue9sistantes au thrips pour le d\ue9veloppement des strat\ue9gies de lutte durable. Soixante-douze vari\ue9t\ue9s du ni\ue9b\ue9 ont \ue9t\ue9 \ue9valu\ue9es dans trois environnements pendant deux saisons en Uganda pour les dommages, le rendement et ses composantes. Les donn\ue9es ont \ue9t\ue9 soumises aux analyses de variance et biplot de l\u2019effet de g\ue9notype et l\u2019interaction entre g\ue9notype et environnement (GGE). Les r\ue9sultats ont montr\ue9 un effet significatif (P<0.001) de l\u2019interaction entre g\ue9notype, environnement pour les scores de dommages caus\ue9s par thrips. Les vari\ue9t\ue9s les plus r\ue9sistantes et stables \ue9taient IT2841*Brown (1.50), MU20B (1.58), EBELAT*NE39 (1.61), WC17 (1.63), WC29 (1.65), MU24C (1.65), WC5 (1.66), NE46 (1.67), WC30 (1.68), NE67 (1.69), and NE51 (1.71). Toutefois, une corr\ue9lation n\ue9gative (r = -0.32) a \ue9t\ue9 observ\ue9e entre les scores de dommage et le nombre de jours de floraison indiquant que la r\ue9sistance observ\ue9e, \ue9tait due \ue0 un \ue9chappement par une floraison tardive. Le cultivar MU9 avait le rendement le plus \ue9lev\ue9 (813, 87 kg ha-1) et constituait le plus adapt\ue9 aux diff\ue9rents environnements alors que les cultivars WC26, NE48, and NE5 \ue9taient les plus adapt\ue9s \ue0 Arua et Serere, et WC48A \ue9tait le plus adapt\ue9 \ue0 l\u2019Institut de Recherches Agricoles de l\u2019Universit\ue9 de Makerere, Kabanyolo (MUARIK). Il y a potentiel de trouver de source de r\ue9sistance parmi les vari\ue9t\ue9s \ue9valu\ue9es

Efficiency and possibilities for Arabica coffee-banana management systems switching in the Mt. Elgon landscape of Uganda

Sustainably intensifying rural agricultural systems is now a development goal that has gained momentum in the recent decades due to a rapidly growing population and feeds directly into the Sustainable Development Goals of ending poverty and hunger. By 2050, the world will be inhabited by 10 billion people, 68% of whom will be city dwellers which will pose serious food and livelihoods security threats to millions of people, especially in Sub-Saharan Africa. The objective of this study was to analyse technical efficiency of four production systems in Arabica coffee-banana farming system of the Mt. Elgon in Uganda and assesses possibilities for switching from one system to another. The study was motivated by the notion that smallholder farmers do not easily adopt new systems because of opportunity costs related to input substitution, input and/or efficiency reduction and systems redesigning. We estimated a production function to measure technical efficiency and ordered the intensification pathways to create a Technical Efficiency (TE) gradient. An ordered logit model was then estimated to determine the factors influencing farmers to switch among systems, by adopting one or more following a TE gradient. Results showed that farmers produced 50% of the maximum possible Arabica coffee output, indicating huge gaps between actual and potential yields. Use of fertiliser for the lowest efficiency. Low-input-low-output pathway and improved coffee genotypes, manure and labour intensification for the higher technical efficiency clusters such as conventional and mild agroecological would also significantly increase the chances of switching from low to highly efficient and sustainable Arabica coffee production systems in the Mt. Elgon watershed of Uganda.L\u2019intensification durable des syst\ue8mes agricoles ruraux est un objectif de d\ue9veloppement durable qui a\ua0\ue9t\ue9 pris\ua0en compte pour mettre fin \ue0 la pauvret\ue9 et la faim dans une population en croissance rapide. Le monde sera habit\ue9 par 10 milliards de personnes, dont 68% seront des citadins en 2050, ce qui posera de graves menaces \ue0 la s\ue9curit\ue9 alimentaire et des moyens de subsistance de millions de personnes, en particulier en Afrique Sub-Saharienne. L\u2019objectif de cette \ue9tude \ue9tait d\u2019analyser l\u2019efficacit\ue9 de technique de quatre syst\ue8mes de production dans le syst\ue8me de culture caf\ue9-banane Arabica du mont Elgon en Ouganda et \ue9value les possibilit\ue9s de passer d\u2019un syst\ue8me \ue0 un autre. L\u2019\ue9tude \ue9tait motiv\ue9e par l\u2019id\ue9e que les petits exploitants agricoles n\u2019adoptent pas facilement de nouveaux syst\ue8mes en raison des co\ufbts d\u2019opportunit\ue9 li\ue9s \ue0 la substitution des intrants, la r\ue9duction des intrants et / ou de l\u2019efficacit\ue9 et la refonte des syst\ue8mes. Nous avons estim\ue9 une fonction de production pour mesurer l\u2019efficacit\ue9 de technique et nous avons ordonn\ue9 les voies d\u2019intensification pour cr\ue9er un gradient l\u2019efficacit\ue9 de technique (TE). Un mod\ue8le logit ordonn\ue9 a ensuite \ue9t\ue9 estim\ue9 pour d\ue9terminer les facteurs qui poussent les agriculteurs \ue0 basculer entre les syst\ue8mes, en adoptant un ou plusieurs suivant un gradient TE. Les r\ue9sultats ont montr\ue9 que les agriculteurs produisaient 50% de la production maximale possible de caf\ue9 Arabica, indiquant d\u2019\ue9normes \ue9carts entre les rendements r\ue9els et potentiels. Utilisation d\u2019engrais pour une efficacit\ue9 minimale. Une fili\ue8re \ue0 faibles intrants et \ue0 faible rendement et des g\ue9notypes de caf\ue9 am\ue9lior\ue9s, du fumier et une intensification de la main-d\u2019\u153uvre pour les grappes \ue0 plus haute efficacit\ue9 de technique telles que l\u2019agro\ue9cologie conventionnelle et douce augmenteraient \ue9galement consid\ue9rablement les chances de passer de syst\ue8mes de production de caf\ue9 Arabica faibles \ue0 tr\ue8s efficaces et durables dans le bassin versant du Mont Elgon en Ouganda

Host-plant and insect-pest compensations, and microclimate as drivers for intensity of Toxoptera aurantii (Hemiptera: Aphididae) in Arabica coffee-banana farming system of mount Elgon region, Uganda

Host-plants and insect-pests\u2019 compensational relationships are known to enable plants and insects to survive and adopt to changing environmental conditions. In the mount Elgon region of Uganda, exists a mosaical pattern of different coffee farming systems with increasing altitudes, and their combinations create differing microclimates, which influence host-plant and pest behaviors. The objective of this study was to determine the host-plant and Toxoptera aurantii compensations in Arabica coffee cropping systems of mount Elgon region in Uganda. A two-year study on the coffee leaf biomass, T. aurantii numbers on the leaf surface, and damage intensity of T. aurantii, was conducted using 72 Arabica coffee farms with mixed coffee polycultures (farming systems). Two independent factors were considered; altitude as a major factor and the farming system as the second factor. There was evidence of significant host-plant and insect-pest compensations; host-plant/microclimates, and insect-pest /microclimates. Linear regression analysis revealed a - relationship (number of leaves /branch / T. aurantii numbers). A + relationship (number of leaves / branch infested by T. aurantii / T. aurantii abundance). Also T. aurantii abundance had a + relationship / RH or/ambient temperature). The Arabica coffee leaves/ branch had a \u2013 relationship (ambient temperature or/ RH). While the T. aurantii infested leaves /branch only had a + relationship with RH. Regarding the soil variables it was only soil temperature which had a + relationship with the number of leaves /branch. The T. aurantii infested leaves /branch had a + relationship (soil temperature or/soil moisture).Les relations de compensation entre les plantes h\uf4tes et les insectes ravageurs sont connues pour permettre aux plantes et aux insectes de survivre et de s\u2019adapter aux conditions environnementales changeantes. Dans la r\ue9gion du mont Elgon en Ouganda, il existe un mod\ue8le mosa\uefque de diff\ue9rents syst\ue8mes de culture du caf\ue9 avec des altitudes croissantes, et leurs combinaisons cr\ue9ent des microclimats diff\ue9rents, qui influencent les comportements des plantes h\uf4tes et des ravageurs. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer les compensations de la plante h\uf4te et de Toxoptera aurantii avec le microclimat dans le caf\ue9 Arabica dans des conditions d\u2019altitudes et de syst\ue8mes de culture diff\ue9rents. Une \ue9tude de deux ans sur la biomasse des feuilles de caf\ue9ier, le nombre de T. aurantii \ue0 la surface des feuilles et l\u2019intensit\ue9 des d\ue9g\ue2ts de T. aurantii a \ue9t\ue9 men\ue9e dans 72 plantations de caf\ue9 Arabica avec polycultures de caf\ue9 m\ue9lang\ue9 (syst\ue8mes agricoles). Deux facteurs ind\ue9pendants ont \ue9t\ue9 consid\ue9r\ue9s; l\u2019altitude comme facteur majeur et le syst\ue8me agricole comme deuxi\ue8me facteur. Il y avait des preuves de compensations importantes pour les plantes h\uf4tes et les insectes nuisibles; plante h\uf4te / microclimats; et insectes nuisibles / microclimats. Une analyse de r\ue9gression lin\ue9aire a r\ue9v\ue9l\ue9 une relation - (nombre de feuilles / branches / nombres de T. aurantii). Relation A + (nombre de feuilles / branches infest\ue9es par T. aurantii / T. aurantii abondance). L\u2019abondance de T. aurantii avait \ue9galement une relation + / RH ou / temp\ue9rature ambiante). Les feuilles / branches de caf\ue9 Arabica avaient une relation - (temp\ue9rature ambiante ou / RH). Alors que les feuilles / branches infest\ue9es par T. aurantii n\u2019avaient qu\u2019une relation + avec le RH. En ce qui concerne les variables du sol, seule la temp\ue9rature du sol a une relation + avec le nombre de feuilles / branche. Les feuilles / branches infest\ue9es par T. aurantii avaient une relation + (temp\ue9rature du sol ou / humidit\ue9 du sol)

Nutritional quality, fruit shape and relationships among exotic and local Capsicum pepper genotypes in Uganda.

Twenty-one hot pepper genotypes comprising of local (15) and exotic (6) types (C. annuum, C. frutescens and C. chinense) were characterized for selected fruit traits after propagation in a glasshouse at the Makerere University Agricultural Research Institute Kabanyolo in Central Uganda using a completely randomized design with three replicates. Ripe fruits were harvested and analyzed; traits evaluated were all significantly different at P<0.05 with variations in quality attributes. The genotype OHA-B305-10 had the highest ascorbic acid content (128.86 mg/100 g) and is recommended for improvement of both local and exotic genotypes targeting the fresh market. Genotypes CAP0408-12 and UG2 WE0511-22, with highest total soluble solids (16.17 ºBrix) and dry matter content (28.59%), respectively should be used in improvements for industrial use or processing to products such as chilli powder or flakes. BRS-M205-04 with highest titratable acidity (1.04%) can be used in enhancing shelf life of genotypes with low titratable acids as well as for the fresh market. In spite of the intraspecific relationships among genotypes, significant differences were observed in their quantitative traits. These genotypes will, therefore, be useful in improving the quality of hot pepper fruit in Ugand

New sources and stability of resistance to aphids in cowpea germplasm across locations in Uganda

Open Access ArticleThe cowpea aphid (Aphis craccivora Koch) is an economically important pest, whose feeding effects cause stunting, delayed flower initiation and yield reduction in cowpea (Vigna unguiculata L. Walp). Host plant resistance offers an alternative for controlling aphids; while simultaneously reducing reliance on chemical pesticides. The objective of this study was to evaluate a multi-parent advanced generation inter-cross (MAGIC) population of cowpea against aphids, across cowpea growing regions in Uganda. The study was arranged in alpha lattice design, with two replicates in three locations over two seasons (2018B and 2019A). Results revealed significant effects (P<0.001) for the main treatment effects, genotype x location and location x season interaction for both infestation and damage. The genotype x season interaction was significant (P<0.01) for both aphid infestation and damage; while the three-way interaction was only significant (P<0.001) for aphid infestation, but not for damage. The study identified five new resistant and stable genotypes from the MAGIC panel, including MAGIC131, MAGIC-132, MAGIC149, MAGIC170 and MAGIC280; and one resistant parent, SUVITA-2. The study further revealed MAGIC-125, MAGIC-171, MAGIC153, MAGIC-333, MAGIC177, MAGIC-292, MAGIC282, MAGIC249, MAGIC162, SEC 4W * SEC 5T, NAROCOWPEA 4, MAGIC-204, MAGIC-039, MAGIC060, MAGIC-097, NAROCOWPEA 3, MAGIC-233, MAGIC090 and MU 9 to be moderately resistant and high yielding genotypes. The above genotypes are recommended for use in the cowpea breeding programme, to develop improved resistant lines against aphids in Uganda

Scaling up of highly active antiretroviral therapy in a rural district of Malawi: an effectiveness assessment.

BACKGROUND: The recording of outcomes from large-scale, simplified HAART (highly active antiretroviral therapy) programmes in sub-Saharan Africa is critical. We aimed to assess the effectiveness of such a programme held by Médecins Sans Frontières (MSF) in the Chiradzulu district, Malawi. METHODS: We scaled up and simplified HAART in this programme since August, 2002. We analysed survival indicators, CD4 count evolution, virological response, and adherence to treatment. We included adults who all started HAART 6 months or more before the analysis. HIV-1 RNA plasma viral load and self-reported adherence were assessed on a subsample of patients, and antiretroviral resistance mutations were analysed in plasma with viral loads greater than 1000 copies per mL. Analysis was by intention to treat. FINDINGS: Of the 1308 patients who were eligible, 827 (64%) were female, the median age was 34.9 years (IQR 29.9-41.0), and 1023 (78%) received d4T/3TC/NVP (stavudine, lamivudine, and nevirapine) as a fixed-dose combination. At baseline, 1266 individuals (97%) were HAART-naive, 357 (27%) were at WHO stage IV, 311 (33%) had a body-mass index of less than 18.5 kg/m2, and 208 (21%) had a CD4 count lower than 50 cells per muL. At follow-up (median 8.3 months, IQR 5.5-13.1), 967 (74%) were still on HAART, 243 (19%) had died, 91 (7%) were lost to follow-up, and seven (0.5%) discontinued treatment. Low body-mass index, WHO stage IV, male sex, and baseline CD4 count lower than 50 cells per muL were independent determinants of death in the first 6 months. At 12 months, the probability of individuals still in care was 0.76 (95% CI 0.73-0.78) and the median CD4 gain was 165 (IQR 67-259) cells per muL. In the cross-sectional survey (n=398), 334 (84%) had a viral load of less than 400 copies per mL. Of several indicators measuring adherence, self-reported poor adherence (<80%) in the past 4 days was the best predictor of detectable viral load (odds ratio 5.4, 95% CI 1.9-15.6). INTERPRETATION: These data show that large numbers of people can rapidly benefit from antiretroviral therapy in rural resource-poor settings and strongly supports the implementation of such large-scale simplified programmes in Africa