Browsing by Author "Godifrey, Juliana"

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Effects of pesticidal plants on legume pollinators’ attraction in the field and bruchids control in storage
(NM-AIST, 2019-04) Godifrey, Juliana
A randomized complete block design was used to set up field and storage experiments to evaluate the effects of pesticidal plants on common bean pollinators’ attraction in the field and Callosobruchus maculatus control in cowpea storage. Pesticidal plants Hyptis suaveolens, Osimum suave, Dysphania ambrosioides and Sphaeranthus suaveolens were planted as field margin plants (FMPs) in a plot size of 5 m x 5 m in a study area of 75 m x 75 m. Pesticidal leaf powder of H. suaveolens, O. suave and D. ambrosioides were used at the rates of 0, 30, 60 and 90 g 1.5 kg-1 of cowpea seeds in storage. The results showed that, all FMPs attracted a good number of pollinators, but O. suave attracted more pollinators than the rest of FMPs. More pods per plant were produced in open pollinated bean plants than in self-pollinated (netted plants) and the control plots (no margins). Higher dosages of plant leaf powders at 60 and 90 g for H. suaveolens and D. ambrosioides and 90 g for O. suave significantly (P ≤ 0.001) affected insects’ mortality, survival and reduced seed damage. Comparatively, H. suaveolens and D. ambrosioides at 90 g was more effective in inhibiting egg deposition by C. maculatus just as successful as the positive control. Therefore, the findings of this study indicated O. suave to have high influence in attracting pollinators, while H. suaveolens and D. ambrosioides at high dosage were effective in protecting the stored cowpea seeds against C. maculatus.
Potentials of Pesticidal Plants in Enhancing Diversity of Pollinators in Cropped Fields
(Scientific Research Publishing, 2018-12-21) Godifrey, Juliana; Mbega, Ernest; Ndakidemi, Patrick
Declines in populations of pollinators in agricultural based landscapes have raised a concern, which could be associated with various factors such as intensive farming systems like monocropping and the use of non-selective synthetic pesticides. Such practices are likely to remove beneficial non-crop plants around or nearby the cropped fields. This may in turn result into losses of pollinators due to loss of the natural habitats for insects therefore, interfering the interaction between beneficial insects and flowering crop plants. Initiatives to restore friendly habitats for pollinators require multidisciplinary approaches. One of these could be the use of pesticidal flowering plants as part of field margin plants with the aim of encouraging the population of pollinators whilst reducing the number of pests. Farmers should be fully engaged in the efforts of creating conducive environments to pollinators and be well equipped with the knowledge of proper habitats management strategies in agricultural fields. Developing appropriate conservation strategies to combat decline of pollinators is of high importance and thus there is a need to evaluate management practices, which potentially favour the populations of pollinators. Therefore, this review aims at unravelling available evidences on habitats manipulation options through provision of flowering plants along the field margins that have shown to increase plant biodiversity surrounding the cropped fields. It also summarizes the options for increasing plant biodiversity, which have improved habitats for the pollinating insects and beneficially boosting pollination services in agro-ecosystems.