Concern in Africa over genetically modified crops has been dismissed as fear of the unknown by an environmental group chaired by Kofi Annan, the former UN secretary general.

A report by the Alliance for a Green Revolution in Africa (Agra), published on Wednesday, describes opposition to GM crops as "a farce". It points out that such crops have been subjected to more testing worldwide than new non-modified varieties, citing reports from the EU, the World Health Organisation and the US national academy of sciences.

Only four African countries – Burkina Faso, Egypt, Sudan and South Africa – have fully commercialised GM crops. But Agra says most countries across the continent are at various stages of creating the environment for commercialisation.

Cameroon, Kenya, Malawi, Nigeria and Uganda are conducting field trials of biotech crops, the final step before full approval of commercialisation. Most African countries have put in place the requisite policy and regulatory frameworks, despite growing public jitters over genetically modified food.

Agra's Africa Agricultural status report states: "There is growing public opposition to GM crops in Africa that is best described as a fear of the unknown. Unless milled, the import of GM foods is banned in Angola, Ethiopia, Kenya, Lesotho, Madagascar, Malawi, Mozambique, Swaziland, Tanzania, Zambia and Zimbabwe. More important to seed-sector development, these bans signal the arbitrariness and unpredictability of public policy."

Agra is an independent organisation based in Kenya that aims to double the income of 20 million small farmers and reduce food insecurity by 50% in 20 countries by 2020. Critics of the group accuse it of showing its true colours after initial coyness over GM foods.

"This report clearly indicates their full support for GM crops, and their intention to use their influence to open African doors for Monsanto's and Syngenta's patented GM crops," said Teresa Anderson, international advocacy co-ordinator for the Gaia foundation, an advocate of food sovereignty that asserts the right of people to define their own food systems.

"Characterising the refusal of most African countries to commercialise GM crops … as 'fear of the unknown' is patronising and shallow. Agra has wilfully chosen to insult farmers' concerns in their aim to expand corporate agribusiness into Africa."

The Agra report urges African countries to further invest in agricultural research and development to ensure food security amid concern that some nations are lagging behind. "In terms of personnel engaged in agricultural research, Africa has the world's lowest capacity, with only 70 researchers per million inhabitants (compared with the US and Japan with 2,640 and 4,380, respectively)," it says.

It notes that smallholder farm yields fall short of the estimated potential for most food crops (cereals and pulses). The average grain yields remained at about one-third to half of the world's average (1.1-1.5 tonnes per hectare versus 3.2 tonnes per hectare) between 2000 and 2010. Sub-Saharan Africa has the greatest gaps between potential yields and realised yields for several crops, particularly maize and rice.

"Plausible explanations for the low yields include lack of access to quality resources such as water, inputs and low use of new technologies that require money – such as fertiliser, machinery and irrigation technology," the report says. "The development and dissemination of new technologies and practices that increase yield potential for a particular area depend on a country's ability to make needed investments, and farmers' skills and willingness to adopt the technologies."

Anderson said the key was quality, not quantity, of research, and questioned the approach of most agriculture research institutes. "They are usually focused on producing a few varieties that claim to address individual (not complex) issues," she said. "Farmers are advised to grow these new varieties instead of their traditional crops. What we are clearly seeing as a result is that seed diversity is disappearing in Africa, while communities complain that the new varieties are tasteless, lack nutrition, or are more vulnerable to particular pests."

The report coincides with a meeting in Maputo, Mozambique, of the African green revolution forum, organised by Agra. The focus of the talks – which bring together heads of state, ministers, NGOs and scientists – is "scaling up and financing inclusive agribusiness through transformative public private partnerships".

The forum takes place 10 years after 40 African countries, convened by the African Union, signed the Maputo declaration, committing at least 10% of their national budgets to agriculture development.