How To Preserve Beans Without Poisonous Chemicals

A bean merchant who demanded anonymity told The Guardian that “what many people didn’t know is that farmers have always been using Sniper to preserve their grains. They don’t feel any remorse when applying it, because according to them, that is the only method they know for beans preservation.”

Bean weevils are common pests that attack beans. Cowpeas are highly susceptible to pest infestation, and this leads to huge post-harvest losses, lower food quality and poor food safety. 

To mitigate these losses... 
the majority of farmers and grain merchants employ various insect control measures, including the use of chemicals not minding the consequences of their actions. 

Chemicals like organophosphates (such as DDVP), pyrethroids (such as Permethrin, Deltamethrin) and some already banned class of chemicals (organochlorides such as gammalin) for the storage of beans and this has led to food poisoning and death of consumers. Therefore, the general public is at risk due to their effects.

To correct the abnormal practice and ensure the safety of foods consumed by the Nigerians, the Ministry of Agriculture and Rural Development conveyed a stakeholders’ meeting in Abuja, bringing together the Nigerian Agricultural Quarantine Agency, the National Agency for Food, Drug Administration and Control (NAFDAC) Standards Organisation of Nigeria (SON), the National Orientation Agency (NOA), and research institutes to find a lasting solution to the menace.

The Minister of Agriculture and Rural Development, Audu Ogbeh, while stressing the need to scale up campaign in ensuring Nigerians consume wholesome foods, noted that it would help prevent cases of liver and kidney problems.

He said: “Why are so many people going down with liver, kidney and lung failures? Nobody knows exactly which particular misconduct of ours is leading to the damage of health of our people. Add all that, water that people are drinking in the communities is contaminated. Then, you can see why our life expectancy is so low.” 

Ogbeh attributed the use of the chemicals to ignorance and poverty. He said rural women often use chemicals to ripen plantain or banana, adding that they also spread cassava products on the roadside, thus exposing foods to carbon deposits, dust and effluents.

The NAQS boss, Dr Vincent Isiegbe, pointed out that NAQS had been trying to engage people along the value chain so as to see how they could work together not only on beans, but also on other grains. He added that since 2017, it had partnered with the University of Ibadan and Ahmadu Bello University, Zaria to find a viable and sustainable bio-degradable agro-pesticide that farmers could apply.

The Executive Director of the Nigerian Stored Product Research Institute (NSPRI), Professor Olorunfemi Peters, further submitted that beans of safe moisture content can be stored with or without the use of chemicals. He explained that harvested and threshed beans could be stored for short and long term periods using the following procedures.

Farmers and marketers could preserve cereals with hermetic storage methods. This technology works on the principle of exclusion of oxygen gas from the storage environment. Hermetic storage facilities are air-tight structures which can be flexible or rigid and require no synthetic chemical application. For example, when using polythene lined jute bags developed by NSPRI, the bag should be filled to the brim with beans and properly tied or sealed. 

Other flexible hermetic storage structures such as the Purdue Improved Crop Storage (PICS) bags developed by Purdue University, USA and ZeroFly Hermetic bags by Vestergaard Frandsen South Africa, are also very effective. “If we do not have access to the flexible hermetics, the rigid hermetic storage made from plastic or galvanised/stainless metals can also be used,” he said.
Both of these structures can be used as domestic, retail and commercial storage for beans and grains in general, and can protect the grains for over 12 months, as long as the air tightness is maintained.

He added that even if the beans had been infested, the infested beans could be placed in air-tight containers and placed in home freezers as a cold shock treatment. This method kills all life stages of the insect within four days. Thereafter, the beans can be removed, sieved, aired and kept in air-tight containers under ambient condition as described above.