We are including a natural pesticide called Diatomaceous Earth (DE) in our three tested storage solutions to see whether this will further reduce weevil infestations.
Two of the major food crops in East Nusa Tenggara province (NTT) are sorghum and maize. However, in developing countries, more than one-third of food is lost or wasted in post-harvest processes, with 50-60 percent of potential grain loss occurring during the storage stage.
In the first phase of this project, Kopernik found that the number of weevils in the tested storage containers were reduced in comparison to traditional storage methods, but a significant number still survived. Kopernik believed this occurred because each time the containers were opened for testing (once per month for six months), we allowed oxygen to enter the container, aiding the weevils survival. Kopernik also considered that one of the solutions - the hermetically sealed plastic drum - was only 30 percent full, creating space for oxygen which may also have assisted the weevils to survive when the drum was sealed.
Building upon these findings, in the second phase of the project, Kopernik filled all three storage containers to capacity with sorghum and sealed them for six months.
Kopernik then learned that under these conditions, the results were much better, with all storage containers having significantly reduced levels of surviving weevils and a safer moisture level.
Kopernik is now interested to test whether there is a solution that allows the farmers more flexibility, enabling the containers to be opened periodically but still have better results than phase one and two.
In phase three of the project, we want to combine the tested storage solutions with a natural pesticide called Diatomaceous Earth (DE) which we hypothesize will have better results than phase one and comparable results to phase two to allow farmers to open their storage containers and still protect their stored grain.
In this experiment, Kopernik’s project team will run two sets of experiments, each consisting of the three storage methods. For each set the three storage containers will be filled with sorghum mixed with DE. The application rate of DE is one kilogram per tonne of grain.
The storage containers in the first set will be opened every month during a six-month period and the second set will be opened only after six months. The following criteria will be collected each time we open the storage containers:
- Number of weevils - dead and alive
- Moisture level
- Rodent breaches
The weight of the sorghum will also be taken at the end of the six months to ascertain whether there has in fact been a better result than the 50-60% crop loss identified in our research.
In addition to that, we will engage sorghum growers, our expert agronomist and buyers to assess the appearance of the sorghum to see if there has been any ill effects on the grain from the DE and also check its quality, developing an economic model to review the containers economic benefits for farmers.
THE EXPECTED IMPACT
We are working with a sorghum farmer in Larantuka, East Nusa Tenggara, Indonesia, who currently experience significant crop loss from traditional storage methods. This project is part of Kopernik’s experimentation projects, a series of small-scale, low-investment tests of simple ideas with the potential to reduce poverty.
THE PROJECT RESULT
The result of the experiment proves that the application of DE to grain during storage can reduce post-harvest loss by 98 percent. The result shows significant improvements from previous phases during which DE was not applied.
Meanwhile, in terms of the moisture content, DE acts as a dehumidifier, resulting in much lower grain moisture content and therefore a very low risk of spoilage due to mold. Even though the moisture levels were very low we did not find any shrinkage of the sorghum in terms of weight and the grain did not appear brittle or easily damaged.
Acknowledging the benefit of significant weevil reduction, and the relatively small investment of US$5 per 150kg (which is likely to be cheaper for larger quantities) for applying DE, we were able to calculate that adding DE can increase farmers’ revenue by up to 87 percent regardless of the storage method used.
Project Implementation & Technology
Costs associated with project coordination and the technology
Monitoring & Evaluation
Costs associated with data collection, analysis and reporting
Cost of transferring payments internationally, processing online donations (5%) and a contribution to Kopernik's operational costs (15%)
This project is implemented by Yayasan Kopernik and Kopernik Japan on behalf of our client who funded this project.