Maize production in Kenya is under threat due to infection by maize lethal necrosis disease (MLND). The disease is known to cause intensive complete yield loss. It is caused by a synergistic infection of maize by maize chlorotic mottle virus and sugarcane mosaic virus which are mainly vectored by corn thrips (Frankliniella williamsi, Hood) and corn leaf aphids (Rhopalosiphum maidis, Fitch) respectively. This study was carried out with the aim of investigating the following aspects; farme...
ABSTRACT Plant parasitic nematodes (PPN) are biotic constraints to crop production worldwide resulting in significant yield losses. Management of these nematodes has primarily depended on chemical nematicides; but due to the increased pressure for more economic and environmentally friendly strategies, alternative methods like organic and conventional amendments, have been considered. To test the efficacy of conventional and farmer practice systems against organic farming in the suppression of...
ABSTRACT Plant-parasitic nematodes, in particular Meloidogyne spp., cause significant yield reduction in commercial pineapple (Ananas comosus) worldwide. In Kenya limited studies have been conducted on nematodes in pineapple although the main commercial producer in Kenya has sole mandate to use Telone II (1, 3-Dichloropropene) indicating the seriousness of the problem. The current study was conducted to provide an update on the occurrence of plant-parasitic nematodes in commercial pineapple f...
ABSTRACT Avocado Persea americana Mill is an important fruit in Kenya. It is a source of vitamins, oil and income to farmers. However, its optimal production is dependent on insect pollinators. This study was undertaken to determine diversity and abundance of insects visiting avocado flowers, their diurnal visitation counts, the crop floral calendar and the effect of pollination deficit of avocado at Kandara, Murang’a County. The study was carried out in farmers’ fields in upper midland ...
ABSTRACT The effects of some cultural practices and some plant extracts on wilt disease of tomato (Lycopersicon esculentum Mill) in Owerri, were studied. The experiments were conducted in 2010, 2011 and 2015 at the Teaching and Research Farm and in the Crop Science and Technology Laboratory of the School of Agriculture and Agricultural Technology, Federal University of Technology, Owerri, Imo State, Nigeria. The investigation consisted of three (3) different experiments and each repeated two...
ABSTRACT The study was conducted in the School of Agriculture and Agricultural Technology (SAAT) research farm. The Experiment was laid out in a RCBD form. Extracts from roots and seeds of Moringa oleifera and Jatropha curcas were tested at 10% concentration and sprayed after 2,3 and 4 weeks in three different growing periods of groundnut; 2, 3 and 4 weeks. Some plant extrated were mixed with 3ml of an emulsifier made from castor oil known as RIMULGAN and then separately added to each of the...
ABSTRACT Application of chemicals on weed has been an effective method of weed control. However, this is with problems of persistence and hazardous effects on non-target organisms like arthropods. Common herbicides used in maize fields in Ogbomoso include atrazine, primextra, Lasso/atrazine, diuron pendimethalin, and S-metolachlor. Information on S-metolachlor and Pendimethalin persistence under field situations is inadequate. Therefore, persistence of S-metolachlor and Pendimethalin in maiz...
ABSTRACT The Russian wheat aphid (RWA) Diuraphis noxia (Kurdjumov) is a serious pest of wheat in Kenya. Development and use of RWA resistant wheat (Triticum aestivum L.) varieties, has been constrained by variations in the resident RWA populations and evolution of virulent biotypes. To fully exploit host plant resistance (HPR) in management of RWA, resident populations of RWA were evaluated for biotypes in order to develop and deploy cultivars that exhibit cross biotype resistance. Three exp...
ABSTRACT Bean Foliage beetles (Ootheca spp.) are a major constraint to common bean production in Kenya. Two studies were carried out during the long and short rain seasons of 2015 to determine the effect of mixtures of bean varieties and other legume species and also to investigate the effect of different bean varieties on bean foliage beetle incidence, population density and severity of damage and grain yield. Field experiments were conducted in six sites (Madola, Bujumba, Busire, Nyalara a...
ABSTRACT Head smut caused by Tolyposporium penicillariae Bref, is a devastating fungal disease that cause up to 30% yield losses in pearl millet Pennisetum glaucum (L.) R.Br.). Pearl millet is the most drought tolerant cereal grown mainly by small scale farmers who cannot afford fungicides. Development of resistant genotypes offers the most economical means of head smut control however this depends primarily on the availability of sources of resistance. The study evaluated host plant resistan...
French bean (Phaseolus vulgaris L.) is an important export vegetable crop that faces serious production challenge due to Ascochyta blight (Phoma exigua). The objectives of this studywere to determine the; (i) antifungal activities of methanol extract of Leonotis nepetifolia and Ocimum gratissimum against Phoma exigua in vitro, (ii) fungicidal effects of extracts of the two test plants on the incidence and severity of Ascochyta blight, and yield of French bean. Methanol extracts of compo...
ABSTRACT Chickpea (Cicer arientinum L.) is an important dry land legume whose full potential in Kenya has not been realized due to abiotic and biotic stresses. The objectives of this study were to evaluate the use of seed treatment and foliar sprays as disease management options against Ascochyta blight caused by Ascochyta rabiei in chickpea. The study was conducted in two sites; Egerton University Njoro and Agricultural Training Centre (ATC) Koibatek. One genotype Chania Desi (ICCV97105) was...
ABSTRACT Cassava brown streak disease (CBSD) is an important disease causing losses of up to 70% in the most susceptible cultivars. Its effects include: reduced root quality due to pitting, root constriction and necrosis, and reduced number and weight of tuberous roots. To contribute to CBSD management, a study was conducted to: (i) Screen East African cassava landraces and F1 populations for CBSD resistance; (ii) Analyse symptom expression and virus accumulation in CBSV graft inoculated cas...
ABSTRACT Food insecurity has been an issue in developing nations worldwide including Kenya. This is as a result of soil related problems, climate change, crop pests and diseases among food crops. Late blight disease caused by Phytophthora infestans in Irish potato (Solanum tuberosum L) is a major challenge among the small-scale farmers in the highlands of Kenya. Yield losses as a result of late blight in Kenya are about 40 - 50%. The appropriate use of fungicides and fertilizers application r...
ABSTRACT Crucifers form an important component of the livelihood of small-scale farmers in East Africa but diamondback moth (DBM) pest constrains their production. Attempts to control the pest by use of host plant resistance (HPR) have been modest especially in cultivars expressing a whitish appearance (normal wax bloom). Conversely, crucifers characterized by their shiny dark green leaves (Glossy) have shown some resistance to DBM. As a consequence, several seed companies claim resistance a...