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Soybean is a very important crop worldwide because of its 40% protein and 20% oil content. However, soybean suffers damage from bruchid (Callosobruchus chinensis) during storage. Understanding of factor(s) contributing to bruchid resistance is useful for development of soybean cultivars with genetic resistance to bruchid damage. Biochemicals associated with resistance to Callosobruchus chinensis were investigated on eight soybean genotypes with varying levels of resistance. Significant differences (P

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A study was carried out during the first and second seasonsofl997 at Namnlonge Agricultural and Animal Production Research Institute {NAAR I) to determine whether there were some soybean varieties in the NAARI germplasm which were resistant to the southern green stink bug, Nezara viridula and to establish the basis of morphological resistance to this stink bug. Some morphological characteristics ofthe soybean plant were considered for the study. During the first season, the soybean genotypes NG ll-36/93A, NC J 1-9/93A and NG2-19/92A '''ere significantly less infested by the stink bugs, while NG9-5/92A and NG I-23/92A were the most infested. In the second season, the most infested genotypes were NG 1-28/92A and NG9-5/92A. The correlation coefficients between the stink bugs and the selected soybean morphological characteristics were very low but significant at P = 0.05. This suggested that the resistance observed was not only attributed to morphological factors, but to many other factors probably bio-chemical factors causing antibiosis.Keywords: Soybean, Nezara viridula, resistance

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The sweetpotato weevil, Cylas brunneus, is a serious insect pest of sweetpotato (Ipomoea batatas (L.) Lam.) in East and West Africa. Knowledge on the influence of temperature on development, reproduction and mortality of this pest is important in understanding its potential population growth and geographical distribution. Such knowledge is a pre-requisite for developing pest control strategies for different agro-ecological zones. The effect of temperature on the development of immature stages, reproduction and mortality of C. brunneus was studied at six constant (15, 20, 25, 30, 35 and 40°C) and at fluctuating temperature range of 22.9 ± 8.7°C. Results obtained indicated that at 15°C and 40°C, there was no development and reproduction of C. brunneus. At 35°C, only 46% of eggs hatched after 1.78 ± 0.20 days but the larvae from these eggs did not pupate. Egg-laying was not possible at 15 °C, 35 °C and 40 °C. The developmental period from egg to adultat 15 °C, 20 °C, 30 °C and 35 °C was 59.43 ± 2.17 days, 49.00 ± 0.93 days, 34.70 ± 0.45 days and 28.67 ± 0.46 days, respectively and tended to decrease significantly with increasing temperature. Similar trend was observed for larval and pupae development time. There was 100 % egg mortality at 15°C and 40 °C. Larval mortality was highest (46 %) at 35 °C and lowest (18 %) at 25°C. After emergence, adults had a pre-oviposition period that ranged from 5.73 ± 0.21 days at 30 oC to 16.17 ± 0.91 at 20°C. C. brunneus laid the highest number of eggs (93.67 ± 10.54 eggs) at 30°C and least eggs (26.33 ± 2.84 eggs) at 20°C. Based on these life table data, the optimal temperature for C. brunneus population growth and development was noted to be 25°C.Key words: Integrated Pest Management, Ipomoea batatas, life-table studies, pest phenology

Coffee is the backbone of Uganda's economy, contributing about 18% of foreign exchange earnings valued at US$ 446 annually. Additionally, nearly 15 million people, draw their livelihood from from coffee-related activities along the value chain. Currently, production of the crop is threatened by a relatively new pest, the black coffee twig borer, Xylosandrus compactus, (Eichhoff) (Coleoptera: Scolytidae). (Here-after referred to as BCTB). A country-wide survey conducted during 2012/13 showed that the pest is rapidly spreading from its secondary epicenter in Kayunga and Mukono districts (Central Uganda) to most of the Robusta coffee growing regions of the country. The survey results further revealed 8.6% death of primary branches that translates into 8.6% loss of coffee export volume and foreign exchange valued at US$40 million annually at the current market prices and production volumes. In related studies, higher BCTB incidences and damage was recorded on shaded than on un-shaded coffee trees. In addition, suveys for its alternate hosts revealed that more than 30 plant species which are commonly intercropped in coffee are alternative hosts of BCTB. These include shade trees like Albizia spp. that have been actively promoted for their excellent shade structure and nitrogen-fixing capacity. Being a relatively new coffee pest in Uganda, there is generally limited information on BCTB and its management. Research efforts to-date have focused on surveillance of its spread and impact with a view of preventing further spread to new areas and minimizing its impact in already infested ones, identifying bio-ecological drivers of its population dynamics, and developing integrated pest management (IPM) packages for its management. A preliminary IPM package has been assembled for use by coffee farmers. This combines community-based phyto-sanitary actions and chemical sprays using imidocloprid (IMAXI or KOHINOR or CONFIDOR) mixed with tebucozanole (ORIUS), eliminating known alternate hosts (including Albizia spp.), proper management of shade trees and coffee canopies, and proper soil fertility and soil moisture management. Future research strategies for better management of BCTB are briefly discussed here.

Drought stress is a constraint to sweetpotato (Ipomoea batatas L. (Lam)) production in many parts of Sub- Saharan Africa. In this region, crop farming is predominantly rain fed; therefore, breeding for drought tolerance is appropriate for addressing low sweetpotato productivity since the crop is largely produced by resourcelimited farmers. As part of developing drought tolerant genotypes in Uganda, this study aimed at determining the nature of genetic control and heritability associated with selected drought adaptation traits. Ten randomly chosen clones from each family were evaluated for three traits; tuber yield, crop vigour and canopy cover as well as five traits (leaf senescence, leaf rolling, leaf retention, SPAD readings and root vertical pulling) at 80% field capacity and under no watering conditions for three weeks in a glasshouse. Diallel analysis revealed significant effects for both GCA and SCA, indicating both additive and non-additive gene actions were present. Baker’s ratio was large in most traits (>0.50), indicating predominance of additive effects. Heritability coefficients were high in most traits (>0.50), indicating that genetic gains can be achieved by conventional breeding. The predominance of additive genetic control realised in this study implies that use of small numbers of parents with suitable GCA effects is most appropriate for drought tolerance improvement in sweetpotato.Key Words: Combining ability, diallel, Ipomoea batatas

Aphis craccivora Koch (Homoptera : Aphididae) is an economic pest of cowpea in eastern Uganda and in eastern Democratic Republic of the Congo (DRC). The earwig Forficula auricularia (Dermaptera : Forficulidae) is a predatory species frequently observed on farms in eastern and central Africa. To determine the predation capability of F. auricularia on A. craccivora, laboratory and field cage experiments were set up in Uganda and the DRC during the rainy seasons of 2004 and 2005, with various predator-prey ratios as treatments. In the laboratory, F. auricularia consumed a range of 1.27 to 7.82 A. craccivora per day, while in the field the range was 3.66 to 7.24. Although this earwig did not demonstrate high predation levels, it is contributing to natural control of insect pests and therefore its populations should be encouraged.Les pucerons, Aphis craccivora Koch (Homoptera : Aphididae) compte parmi les ravageurs d\'importance économique du niébé à l\'Est de l\'Uganda et à l\'Est de la République Démocratique du Congo. Le perce-oreille commun, Forficula auricularia (Dermaptera : Forficulidae) est un prédateur fréquemment rencontré dans les agro-écosystèmes intégrant le niébé en Afrique centrale et orientale. L\'action prédatrice (la capacité de prédation) exercée sur les pucerons par le perce-oreille commun, a été évaluée en conditions de laboratoire et de champs. Les essais de cage en champs ont été installés dans les terrains expérimentaux en Uganda et en République Démocratique du Congo, durant la petite et la grande saison pluvieuses des années 2004 et 2005. Dans ces essais, différents traitements de prédateur-proie ont été évalués. Les résultats montrent que F. auricularia est capable de consommer environs 1,27 à 7,82 pucerons par jour en conditions de laboratoire. En milieu réel (champ), F.auricularia consomme 3,66 à 7,24 pucerons par jour. Malgré le fait que l\'insecte n\'a pas démontré un taux élevé de consommation journalière des pucerons, il pourrait néanmoins contribuer à la réduction de l\'augmentation des colonies du ravageur (Aphis craccivora) en milieu paysan. Les perce-oreilles peuvent jouer un rôle important en lutte biologique contre les pucerons puisque ils sont potentiellement important agents de contrôle naturel de ces ravageurs. Ainsi, une forte densité, de ce prédateur dans les agro-écosystèmes intégrant le niébé et cultures céréalières, est à encourager en Afrique centrale et orientale Keywords: Predation capability, Forficula auricularia, Aphis craccivora, Uganda, D. R. CongoAgronomie Africaine Vol. 20 (1) 2008: pp. 49-58

Increased adoption of climbing beans (Phaseolus vulgaris L.) in Kabale district, south-western Uganda, has been limited by scarcity of staking materials, despite the crop\'s higher yield potential compared to bush bean types when grown on fertile soils. There is therefore need to explore other appropriate mechanisms such as intecropping, that could substitute use of stalks. A field experiment was conducted at Kachwekano near Kabale town for two seasons: second rains of 1996 (1996b) and first rains of 1997 (1997a), to determine the appropriate plant population density (PPD) of maize that would maximize bean yield in an intercrop system. The treatments were: (a) maize PPD ranging from 25 000 to 40 000 plants ha-1, and (b) bean PPD ranging from 57 142 to 95 238 plants ha-1. Sole crops were planted at the recommended PPD of 44 444 and 111 111 plants ha-1 for maize and climbing beans, respectively. Maize in mixtures was planted in single rows 1.0 m apart. Two rows of beans were planted in the space between maize rows, 10 days after maize emergence. Plant densities were achieved by varying the within-row spacing from 0.25 to 0.40 m for maize and 0.30 to 0.50 m for beans. Maize PPD significantly affected bean yield only during the second rains (1996b), probably due to a favourable moisture regime. Bean PPD significantly affected maize yield only during the first rains (1997a), presumably due to drought stress. The highest intercrop bean yield of 1.075 t ha-1 was realised from a final mixture of 24 575 and 66 666 plants ha-1 of maize and beans, respectively, during the second rains. Intercropping significantly reduced maize yield during the second rains and bean yields in both seasons. The intercrop system had a yield advantage of 26 % (i.e., LER = 1.26) over pure stands of the component crops only during the second rains, presumably due to complementary use of resources. However, there were no yield advantages observed during the first rains probably due to drought stress. Mean total income (TI) from the mixtures was 226.8 and 31.8% higher than income from sole bean and maize crops, respectively, during the second rains. Income from the mixtures was 58.7 and 72.5 % higher than income from sole bean and maize crops, respectively, during the first rains. Key Words: Competitive ratio, land equivalent ratio, Phaseolus vulgaris, Uganda, Zea mays RESUME L\'adoption croissante d\'haricot grippant (Phaseolus vulgaris L.) dans le district de Kabale au sud-ouest de l\'Ouganda, a été limitée par le manque des matériels de soutien, en dépit du potentiel élevé du rendement des plantes comparé au haricot des types forestiers lorsque cultivé sur des sols fertiles. Il y a donc un besoin d\'explorer les autres mécanismes appropriés tel que l\'inter culture, qui pourrait substituer l\'usage des tiges. Une expérience sur terrain était conduite à Kachwekano près de la ville de Kabale pendant deux saisons : secondes pluies de 1996 (1996b) et premières pluies de 1997 (1997a), pour déterminer la densité de population des plantes appropriée (PPD) de maïs qui pourrait maximiser le rendement de haricot dans un système d\'inter culture. Les traitements étaient : (a) PPD de maïs s\'étendant de 25000 à 40000 plantes ha-1, et (b) PPD de haricot allant de 57142 à 95238 plantes ha-1. Seule les plantes de même nature étaient plantées à PPD recommandée de 44444 et 111111 plantes ha-1 pour le maïs et haricot respectivement. Le maïs mélangé était planté en lignes uniques de 1,0 m de distance. Deux lignes de haricot étaient plantées dans l\'espace entre les lignes de maïs, 10 jours après l\'emergemce du maïs. Les densités de plantes étaient atteintes en variant l\'espace entre lignes de 0,25 à 0,40 m pour le maïs et 0,30 à 0,50 pour le haricot. La PPD de maïs avait significativement affecté le rendement de haricot seulement durant les secondes pluies (1996b), probablement à cause d\'un régime humide favorable. La PPD de haricot a significativement affecté le rendement de maïs seulement durant les premières pluies (1997a), vraisemblablement à cause de la sècheresse. Le rendement le plus élevé de haricot en inter culture de 1,075t ha-1 était réalisé à partir d\'un mélange final de 24575 et 66666 plantes ha-1 de maïs et haricot respectivement, durant les secondes pluies. L\'inter culture a significativement réduit le rendement de maïs durant les secondes pluies et les rendements de haricot dans les deux saisons. Le système d\'inter culture avait un avantage de rendement de 26% (c. à.d, LER=1,26) sur les témoins purs des composantes des plantes durant les secondes pluies, vraisemblablement à cause de l\'usage des ressources complémentaires. Cependant, il n y avait pas des avantages de rendements observés durant les premières pluies probablement à cause de la sécheresse. La moyenne totale de revenus (IT) des de cultures mélangées était 226,8 et 31,8% élevée que le revenu des plantes d\'haricot seul et maïs seul respectivement, durant les secondes pluies. Le revenu des cultures mélangées était 58,7 et 72,5% élevé que le revenu des plantes de haricot seul et maïs seul respectivement, durant les premières pluies. Mots Clés: Proportion compétitive, proportion équivalente de terre, Phaseolus vulgaris, Ouganda, Zea mays African Crop Science Journal Vol. 13 (1) 2005: 83-93

(Received 15 October, 2001; accepted 2 July, 2002) Abstract The IPM CRSP (Integrated Pest Management Collaborative Research Support Program) has been applying a farmer participatory IPM strategy at on-farm research sites in eastern Uganda since 1995. Following five years of project implementation an evaluation of project impacts was conducted using a stratified random sample of 200 small- scale farmers. The main purpose of this study was to evaluate the impact of project (IPM CRSP) activities on IPM knowledge and awareness change using comparison groups composed of project participants and non-participants. A summated ratings scale consisting of four attributes was developed to measure knowledge of IPM and individual indices were developed to measure crop specific pest management knowledge. Results indicate that more active participation increased knowledge of IPM skills and knowledge, provided preliminary support for the project's participatory research and extension approach. However, diffusion of knowledge was limited and project beneficiaries were slightly more socioeconomically advantaged. Several recommendations are made for increasing the number of farmer participants and improving the evaluation process. Key Words: Beneficiaries, diffusion, evaluation, on-farm, participatory approach Résumé Les IPM CRSP était entrain d'appliquer une stratégie participative à des sites de recherches à l'est de l'Ouganda depuis 1995. Après cinq ans de réalisation du projet, une évaluation de son l'impact était conduite utilisant un échantillonnage stratifié au hasard et 200 petits fermiers. Le but principal de cette étude était d'évaluer l'impact des activités du projet (IPM CRSP) sur la connaissance des IPM et le changement de conscience en comparant des groupes des participants et non participants au projet. Une échelle de classement sommative, avec quatre attributs, était développée pour mesurer la connaisance sur les IPM et des indices individuels étaient développés pour mesurer la connaissance spécifique sur la gestion des pestes. Les résultats indiquent que la participation active augmente la connaissance technique des IPM, si un support préliminaire est assuré dans l'approche de la recherche participative et l'extension. Cependant, la dissémination de connaissances était limitée et les bénéficiaires du projet étaient un peu avantagés sur le plan socio-économique. Plusieures recommendations étaient faites pour augmenter le nombre des fermiers participants et améliorer le processus d'évaluation. Mots Clés: Bénéficiaires, dissémination, evaluation, sur fermes, approche participative (Af Crop Sci J 2002 Vol 10 No 3 pp271-280)