The right storage container can bring multiple advantages for smallholder farmers and rice milling companies. The use of hermetic storage containers is a green alternative for the safe storage of paddy rice without the need for the application of pesticides. The quality of rice paddy can be greatly affected during storage, particularly when farmers or millers use traditional materials or have subpar facilities with limited space, leaking roofs, and insufficient protection from pests.
Insect infestation, in particular, causes significant losses in stored grains as well in the quality of the grains. This could lead to the reduced income of farmers and other post-harvest stakeholders who have to sell the paddy at lower prices.
The major insect pests that attack rice paddy in storage include the lesser grain borer (Rhyzopertha dominica), rice weevil (Sitophilus oryzae), granary weevil (Sitophilus granarius), angoumois grain moth (Sitotroga cerealella), kapra beetle (Trogoderma granarium), saw-toothed grain beetle (Oryzaephilus surinamensis), red flour beetle (Tribolium castaneum), flat grain beetle (Cryptolestes pusillus), and cadelle (Tenebroides mauritanicus).
Insect infestations in stored paddy are often treated with pesticides to control the damaging pests. However, the use of pesticides has a number of downsides. Not all farmers may know the chemical products, the proper use, and the right time of application. Late treatment, adulterated chemicals, and incorrect dosage can reduce the effectiveness of the treatment.
The effect of chemical fumigation is limited in traditional or poorly constructed facilities with inadequate protection from re-infestation. Insects may build a tolerance to the pesticides which can render the chemicals ineffectual. Toxic residues can pose health hazards to farmers, consumers, and the environment. These products may also be too expensive for smallholder farmers with scant resources.
The indiscriminate use of pesticides can lead to rejection in the export market with strict standards for the acceptable level of pesticide residues in rice.
In a recent study, Effectiveness of hermetic containers in controlling paddy rice (Oryza sativa L.) storage insect pests, researchers examined the helpfulness of different preventive packaging materials as a pesticide-free tool for protecting paddy rice in storage.
Naturally infested paddy rice was used to compare the effectiveness of polypropylene bags and hermetic storage containers over 12 months of storage in a warehouse against the lesser grain borer, red flour beetle, rice weevil, angoumois grain moth, and flat grain beetle.
When compared to hermetic storage containers, polypropylene bags showed the highest average infestation level after six months of storage, representing about 8-fold of the number of insects recorded in hermetic containers in the same period.
In polypropylene containers, the percentage of damaged grain and weight loss increased significantly reaching 7% and 6%, respectively, whereas grain damage in polyethylene drum hermetic containers was only 3% and the weight loss in grains stored in GrainSafe Bag was 2%.
GrainSafe is based on a low-cost and user-friendly hermetic storage developed by the International Rice Research Institute (IRRI Superbag) and GrainPro Inc commercially available to farmers and processors. The IRRI Superbag fits as a liner inside existing storage bags (e.g., woven polypropylene or jute bags) allowing the safe storage of cereal grains, maize, coffee, and other crops for extended periods.
The results from the study show that the use of hermetic storage containers is a green alternative for the safe storage of paddy rice for 12 months without the need for the application of pesticides. Thus, the right storage container can bring multiple advantages for smallholder farmers and rice milling companies.
Read the full study:
Covele G et al. 2020. Effectiveness of hermetic containers in controlling paddy rice (Oryza sativa L.) storage insect pests. Journal of Stored Products Research. Vol. 89: 12.