Titolo della tesi: The role of crop agrobiodiversity in improving production systems and food security in developing countries
Agricultural biodiversity includes all components of biological diversity relevant for food and agriculture, as well as the components of biological diversity that constitute the agroecosystem. It provides humans with food and raw materials for goods and it can contribute to maintaining and increasing soil fertility, mitigating the impact of pests and diseases and contributing to the stability and the resilience through enhancement of ecosystem services of the production systems. In order to ensure food security for a continuously growing population it is critical that such diversity is understood maintained and managed in a sustainable manner. In developing countries, livelihood of small-holder farmers depends on their capacity to use and maximise the potential of the genetic resources they have available.
In this thesis the role of agrobiodiversity in developing countries is addressed from different perspectives both theoretical and practical. On the one hand, I present a framework to enhance the adoption of new varieties in smallholder production system in remote areas to broaden the genetic base of crop diversity for enhancing system resilience and provide diversity rich options to farmers for managing environmental variability and biotic and abiotic production constraints. A book chapter is also presented illustrating principles and advantages of deploying agrobiodiversity in the form of varietal mixtures to minimize the impact of pests and diseases in the field.
On the other hand, I present results from two pilot research studies.
The first, investigates the role of diversity in providing nutritional content in groundnuts in Uganda. Nutrient composition and consumers’ preferences were determined for twenty local farmer (landrace) and commercial varieties grown in two districts of the central wooded savanna of Uganda. Significant differences in nutrient content and between nutrient content and consumers’ preferences for varieties within and across sites were identified. The differences in nutrient content influenced key organoleptic characteristics, including taste, crunchiness, appearance, soup aroma, which contributed to why consumers may prefer certain varieties to others. Gender differences in variety selection were significantly related to consumer preference for crunchiness of roasted groundnut varieties. The results imply that selecting different varieties of groundnuts enables consumers to receive different nutrient amounts, while experiencing variety uniqueness. Promotion of intraspecific diversity is crucial for improved nutrition, organoleptic appreciation and livelihood of those engaged in groundnut value chains, especially for the actors who specialize in different products.
The second study investigates the role of intraspecific diversity and farmers’ management practices in reducing mycotoxin contamination. Mycotoxins are chemical contaminants invisible, tasteless, chemically stable and resistant to temperature and storage. Contamination along the agri-food chain is difficult to control since production and spreading are due to numerous factors including temperature, relative humidity, insect infestation, and susceptibility of the host plant. This study aims at assessing the contamination level of mycotoxins (DON, NIV, OTA) in thirty-seven varieties of Ethiopian durum wheat, and aflatoxins in thirty-nine varieties of Ugandan groundnuts, grown in non-intensive rainfed production systems. Results indicate absence of mycotoxin contamination in all durum wheat samples and contaminations below the maximum levels tolerated by international standards (e.g. EU and Codex Alimentarius) in groundnut samples.
Overall, there results highlight how diversification represents an opportunity to change the production system in developing countries in a way that it fosters sustainability while at the same time enhancing productivity and stability.