Agricultural Sciences

This course examines the production of high quality food from perennial fruit crops, wine grapes, vegetables. It also covers the key aspects of the postharvest handling and quality assurance of fresh produce.

As land plants are sessile organisms, they have evolved sophisticated defense mechanisms against various environmental stresses. To survive and reproduce, plants adapt to stresses by changing their physiology and gene expression. Insect herbivores are one of major biotic stresses to plants. As plants are the main nutrient sources for these insects, plants have evolved with a number of defense mechanisms to protect themselves. This course explains crop-insect interaction from several aspects (molecular mechanisms, traits, ecology, evolution, and practical farming management). Topics: plant traits to insects, insect traits to plants, tritrophic interactions, plant community ecology and evolution, and implications of crop-insect interactions. Text: C.M. Smith, PLANT RESISTANCE TO ARTHROPODS: MOLECULAR AND CONVENTIONAL APPROACHES; L.M. Schoonhoven, J.J.A. van Loon, and M. Dicke, INSECT-PLANT BIOLOGY. Assessment: final report, presentation, midterm exam, attendance and participation.

The course is an introduction to soil degradation. It covers historical developments in soil degradation, causes and forms of soil degradation (biological, chemical, physical), the extent of soil degradation in Ghana, the GLASOD project, use of GIS to assess soil degradation, and principles and methods of rehabilitation and reclamation of degraded soils – regulations, policies, and community involvement.

This course examines the study of the interactions between crop plants and their abiotic and biotic environments within the tropical agroecosystem. In this course, the focus is on the environmental relations of individual crop species (autecology). Characteristics of the crop production system will be studied along with human and environmental influences on the provision of ecosystem services, resource use efficiency, crop yield, and sustainability. Crop evolution, breeding and distribution will be explored using selected crop examples and taking into account propagation issues, environmental influences and crop production goals. Physical factors of particular interest include solar irradiance, temperature, water supply, atmospheric conditions, and soil characteristics (including mineral nutrient supply). The balance of carbon, energy, water, and mineral nutrients in crop ecosystems is also relevant for the analysis of input use efficiency. Biotic factors of interest include cropping system features, plant density, weeds, pests, diseases, and beneficial organisms. Biotic and abiotic stress factors will be identified along with the nature of plant stress injuries and adaptations/manipulations that favor growth and production in suboptimal environments. Integrated approaches for the management of abiotic and biotic constraints to crop production will be considered.