Output 1: Field trials in three agro-ecological zones in Tanzania to test DEs against LGB

Progress report:

Admixing grain protectants, Arri village

Community research trials were set up in three regions of Tanzania (Shinyanga, Dodoma, Manyara) to test and compare the effectiveness and acceptability of different treatments for protecting grain from insect damage during storage. These initial comparative tests are being run for two 10-month storage seasons from July - May 2002/2003 and 2003/2004. The treated commodities include maize, sorghum and beans. The treatments include:

• the diatomaceous earths’ (DE), Protect-It® and Dryacide® at two concentrations 1g/kg and 2.5g/kg (these concentrations were chosen based on laboratory studies with P. truncatus)
• Protect-It® (1g/kg) in combination with permethrin (2mg/kg)
• Actellic Super dust (100g/90kg)
• Traditional local grain protectant practice, which varies between each trial site but is typically admixture of unwinnowed grain with rice husk or animal dung ash or a mixture of ash and dried plant material,
• Untreated control

In the second season two additional treatments were added to the Dodoma region maize storage trials:

• Local DE sample (from the Kagera deposit in Tanzania) at 250g/100kg
• Stocal Super dust (a recently registered organophosphate and pyrethroid combination protectant) at 100g/ 90kg

The data collected during the first 40 week storage seasons trials show that insect damage increased rapidly from September onwards and was much higher in the untreated control and traditional protectant treatments than in the DE or Actellic Super dust treatments (see graphs). Farmers appeared impressed by the differences in numbers of insects seen crawling on the outside of the sacks of the different treatments and in the samples themselves.

Disaggregated wealth groups of farmers in each of the five trial site villages in Tanzania evaluated samples of the different treatments (code labelled) (in April -May 2003 following 40 weeks storage) using their own grain quality criteria and were impressed by the DE and Actellic Super dust treatments, a draft report of this work has been produced, the final version will shortly be available on this website.