Smallholder food security in sub-Saharan Africa: the case for diatomaceous earth grain protectants
Stathers, Tanya (2008) Smallholder food security in sub-Saharan Africa: the case for diatomaceous earth grain protectants. PhD thesis, University of Greenwich.Full text not available from this repository.
Researchers decided to explore whether diatomaceous earths (DEs) might meet the grain protection demands of rural households. These inert dusts are non-toxic to mammals but deadly to insects absorbing the wax from the insect’s cuticle which leads to water loss and death. Following laboratory studies, promising commercial DEs were trialled collaboratively by researchers and farmers as grain protectants in Zimbabwe. Protect-lt and Dryacide applied at 0.1%w/w were as effective as the synthetic conventional insecticide, Actellic Super dust, in limiting insect damage on stored maize, sorghum and cowpea grains for periods of eight months. However, laboratory studies revealed that the devastating larger grain borer now spread throughout many African countries was more tolerant to DEs than the storage pests found in Zimbabwe. This initiated the testing of DEs in combination with other products. Higher DE application rates of 0.25%w/w, a DE-pyrethroid combination and a local African DE were successfully tested by farmers in Tanzania. During this work the importance of the link between a potential technology such as DEs and the wider post-harvest service provision context became clearer. This led to the exploration of this context using: an enquiry approach to learn about post-harvest decision making amongst diverse rural households; and an experimental learning process to empower farmers. As the nature of the different stakeholders within the agricultural innovation system and their information requirements became more central to the work, the importance of the patterns of interaction amongst them and associated attitudes was repeatedly revealed. A learning alliance of key post-harvest stakeholders was established to explore and test opportunities for stakeholders to work together differently to help overcome institutional and other constraints.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||silicon dioxide, sedimentary rocks, grain protection, post-harvest management, Africa|
|Subjects:||S Agriculture > SB Plant culture|
|Faculty / Department / Research Groups:||Faculty of Engineering & Science > Natural Resources Institute|
|Last Modified:||18 Oct 2016 09:13|
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