Incidence of arthropod pests and diseases of groundnut (Arachis hypogaea L.) in northern Ghana

Groundnut (Arachis hypogaea L.) is the most popular grain legume crop in Ghana in terms of cultivated area and utilization. Though the bulk of the crop is produced in the Northern Guinea and Sudan savanna zones of the Country yields are marginally low, owing to a variety of abiotic and biotic constraints. Systematic studies on the pest and disease profile of the crop in the area remain scanty, even though preliminary observations suggest that these probably cause appreciable damage to the crop annually. The studies described in this paper were therefore conducted to identify the key pests and diseases associated with the crop, damage caused as well as control measures usually adopted by farmers. Combinations of farmer interviews and direct field sampling were carried out between 2014 and 2015 in five districts viz; Tolon, Savelugu, West Mamprusi in the Guinea savannah as well as in Bongo and Builsa North in the Sudan Savannah. Most farmers (80%) were able to mention and/or describe the key field pests and diseases often associated with groundnuts in Ghana, with termites, millipedes, white grubs and virus diseases being most frequently mentioned. Inspite of this knowledge, as many as 64% of farmers took no measures to control pests and diseases on their farms. Sampling of farms in the areas largely confirmed the farmer perceptions and responses in terms of the key members of the pest complex. Though many of the observed pests and diseases (especially the foliar ones) proliferated in most farms sampled, the relative abundance scores (RAS) showed that their incidence and damage were generally low or moderate. Termites, millipedes and rosette were the exception with RAS of over 3.0 on the 1 – 5 scale used, suggesting that these could be of economic importance. These preliminary findings call for more detailed studies to determine the relative importance of the various pests and diseases in groundnut production and to develop and/or disseminate innovations for controlling the economically-damaging ones

Insects infesting sorghum (Sorghum bicolor L. Moench) panicles in northern Ghana. 1. Distribution, species composition, and damage potential

Surveys in the Upper East Region showed that sorghum panicles were attacked by an insect pest complex of which midge, mirid and pentatomid bugs and head caterpillars were most prominent. Midge was most important on late-planted sorghums while mirid bugs constituted the main pests of early sorghums. The mirid bug complex (Heteroptera: Miridae) was dominated by Eurystylus oldi (Poppius), but Creontiades pallidus (Rambur), Campylomma angustior (Poppius), Taylorilygus sp. and Megacoelum apicale (Reuter) also proliferated on most farms. Important predators associated with head bugs included earwigs, Forficula senegalensis Serville (Demaptera: Forficulidae) and assassin bugs, especially Cosmolestes pictus Klug (Heteroptera: Reduviidae). Yield loss estimates showed that controlling either head bugs or midge alone increased grain yields by 23-35 and 26-38 per cent, respectively, while controlling both pests increased yield by up to 63 per cent. Farmers recognized panicle feeders as pests on their crops, but usually did not think they caused economic damage; hence, farmers made no conscious efforts to control them. This is probably because most of them grow local guinense-type sorghums, which are known to be less susceptible to panicle pests compared to the improved caudatum types. Des sondages entrepris partout dans la Région d\'Upper East révélaient que les panicules de sorgho sont ravagées par l\'ensemble d\'insecte ravageur dont le moucheron, le mirid, le pentatome ( punaise de bois ) et les chenilles sont plus marquants. Le moucheron était plus important sur les sorghos semés tardivement alors que les punaises mirids constituaient les ravageuses principales de sorghos tôt. L\'ensemble de punaise mirid (Hétéroptère : Mirid) était dominé par Eurystylus oldi (Poppius), mais Creontiades pallidus (Rambur), Campylomma angustior (Poppius), Taylorilygus sp. et Megacoelum apicale (Reuter) aussi proliféraient sur la plupart de champs. Les prédateurs importants associés avec les punaises comprenaient les perce-oreilles, Forficula senegalensis Serville (Demaptera : Forficulidae) et les triatomes surtout Cosmolestes pictus Klug (Hétéroptère: Reduviidae). Les estimations de perte de rendement montraient que la lutte contre soit la punaise soit le moucheron seulement augmentait les rendements de grain par 23-35 et 26-38%, respectivement, alors que la lutte contre les deux ravageurs augmentait le rendement par jusqu\'à 63% . Les agriculteurs reconnaissaient les mangeurs de panicule comme de ravageurs sur leurs cultures mais dans la plupart des cas ne pensaient pas qu\'ils provoquaient des dommages à l\'économie et ne faisaient donc pas aucun effort consciencieux pour lutter contre eux . C\'est probablement à cause du type guinense local, qui sont reconnu d\'être moins prédisposé aux ravageurs de panicule que les types de caudatum amélioré. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 43-5

Assessment of yield losses in groundnut (Arachis hypogaea L.) due to arthropod pests and diseases in the Sudan savanna of Ghana

The present study was undertaken to assess the relative abundance and extent of damage caused by the various pests and diseases attacking groundnut in the Sudan savanna zone of the country during the 2015 and 2016 cropping seasons. Selective applications of fungicides and insecticides were deployed in field experiments to assess the damage caused by the key members of the groundnut pest/disease complex namely the soil pests, foliar insects, and foliar diseases. Results showed that most treatments significantly reduced the incidence of the targeted pests and diseases, resulting in lower crop damage and higher yields. Providing full protection to the crop (T6) gave the highest mean kernel yield (mean 930 kg/ha) followed by control of soil pests (T1) and leaf spots (T4) which recorded yields 677 and 640 kg/ha respectively. Totally neglecting pest and disease control (T7) resulted in 57.3% yield reduction, while controlling soil pests (T1), foliar diseases (T4) and foliar insects (T5) reduced yield losses to 27%, 32% and 37% respectively suggesting that these are key pests that need to be controlled to guarantee profitable and sustainable groundnut production in the study area

Incidence and Management of Aflatoxin Contamination in Groundnut (Arachis hypogaea L.) in Northern Ghana

Aflatoxin contamination levels were monitored in groundnut products derived from participatory on-farm demonstration plots, farm stores and markets in 21 districts in Northern Ghana in 2015 and 2016. Results clearly showed that improved production technology (variety + agronomic practises) significantly reduced aflatoxin contamination and increased kernel yield. Though no clear and consistent trend of varietal differences in aflatoxin contamination could be established from the studies over the two years across locations, NkatieSari showed the least mean contamination (2.74 ppb and 2.39 ppb) while SAMNUT 22 had the highest levels of contamination (7.51 ppb and 3.31 ppb) in 2015 and 2016 respectively. Most groundnut products sampled from households and markets, had aflatoxin levels higher than the EU acceptable limit of 4 ppb and this calls for more intensive sensitization of value chain actors, especially the processors, and rigorous monitoring of groundnut products to minimize the risks of human and livestock poisoning from aflatoxin contamination

Biological control of the millet head miner Heliocheilus albipunctella in the Sahelian region by augmentative releases of the parasitoid wasp Habrobracon hebetor: effectiveness and farmers’ perceptions

On-farm augmentative releases of the parasitoid Habrobracon hebetor (Say) for controlling the millet head miner (MHM) Heliocheilus albipunctella (de Joannis) were tested in Burkina Faso, Mali and Niger from 2007 to 2009. In addition, a survey of farmers’ perceptions of insect pests, with particular focus on MHM, and the biological control program (BCP) was carried out. There was a significant increase of MHM parasitization rate after the releases, with up to 97% mortality. The survey on farmers’ perceptions revealed a fair knowledge of the MHM and the ability of farmers to describe the pest and the damage it caused. Farmers claimed that the biocontrol agent H. hebetor is effective and perceived a significant gain in grain yield due to this control strategy. Implications of these findings for a large extension of the MHM biocontrol program are discussed

Welfare impacts of improved groundnut varieties adoption and food security implications in the semi-arid areas of West Africa

This paper investigates the welfare impacts of improved groundnut adoption in Ghana, Mali, and Nigeria using three-year balanced panel data collected from 2,868 households. We apply the Cragg double hurdle model to understand the adoption process and a fixed-effects instrumental variable approach to estimate the impact on gross margins, household income, per capita income, food security, and poverty. The results show that a 10% increase in the area planted with improved groundnut varieties is associated with a 25.6%, 14.8%, 6.9%, and 23.6% increase in groundnut gross margins, household income, per capita income, and food consumption score, respectively. Likewise, this leads to a 3.6% poverty reduction. The highest average impact is found in Nigeria, followed by Ghana and Mali. Furthermore, disaggregating the impacts by adoption history reveals that households that continuously adopted the improved groundnut varieties benefited more than other categories of adopters. They enjoy a 6.6% poverty reduction compared to 1.9% for households that cultivated improved groundnut varieties for a single year. We conclude that improved groundnut varieties' adoption is a promising pathway for rural poverty alleviation and food security improvement. Hence, encouraging households to adopt improved groundnut varieties for consecutive years could help capitalize on income gains and contribute to raising households above the poverty threshold

Maize–legume strip cropping effect on productivity, income, and income risk of farmers in northern Ghana

Maize (Zea mays L.)–legume intercropping is common cropping system among smallholder farmers in West Africa. However, little is known about the income risk reduction associated with maize–legume strip cropping in West Africa. A 3‐yr study was conducted in Upper West and Northern regions of Ghana to determine the effect of maize–legume strip cropping on productivity, income, and income risk using a randomized complete block design with five replications in each region. Seven treatments were used: sole crops of maize (M) cowpea [Vigna unguiculata (L.) Walp.] (C) and groundnut (Arachis hypogaea L.) (G), a combination of two rows of M and two rows of legumes (L) (2M:2C and 2M:2G), and two rows of M and four rows of L (2M:4C and 2M:4G). Maize–legume strip cropping options (2M:2L and 2M:4L) on the average saved 90–100% of agricultural land, significantly increased income by about threefold, and reduced risk of operating at a financial loss by 75% compared with sole cropping. Smallholder farmers, especially sole legume cropping farmers in the Guinea savanna of northern Ghana and similar agro‐ecologies in West Africa, could adopt maize–legume strip cropping systems (2M:4L or 2M:2L) to mitigate production risk and increase financial return