This post is written by Dr. Anthony Shelton, Matt Hayes and Joan Conrow.

Eggplant is an extremely popular crop in Bangladesh and is essential to food security in the country. The vegetable is part of the daily diet for the 161 million people in Bangladesh and is grown by an estimated 150,000 farmers. Being the dominant winter vegetable in the country, eggplant is cultivated on 28 percent of the growing area dedicated to vegetables and provides important cash to resource-poor farmers. But there is a problem; the destructive eggplant fruit and shoot borer (EFSB) forces farmers to spray expensive and toxic insecticides more than 80 times each growing season to try and control the insect and its voracious appetite. 

Despite intensive spraying multiple times each week, farmers still incur tremendous losses of 60 percent or more which results in millions of dollars of losses. And more importantly, such intensive use of toxic insecticides affects the health of farmers, consumers, and the environment.

A game-changer for farmers and consumers

As an alternative to this unsustainable practice, a public-private partnership was formed in 2003 with funding from USAID to Cornell University to lead a consortium to develop eggplant engineered to express a protein from a common bacterium, Bacillus thuringiensis (Bt). Working with the Indian seed company Mahyco and the Bangladesh Agricultural Research Institute, nine varieties of Bt eggplant were developed that eliminate the need to spray for EFSB. Four of these varieties received regulatory approval in 2013 and were grown by 20 farmers in 2014. Today more than 27,000 farmers in Bangladesh grow Bt eggplant, and there are indications that more farmers are eager to reap the benefits of these improved varieties.

Making gains in Bangladesh

A new study published in May 2020 in the peer-reviewed journal Frontiers in Bioengineering and Biotechnology confirms the economic and environmental benefits of this genetically-engineered eggplant for farmers and its acceptance in the Bangladeshi market.

The study involved interviewing equal numbers of Bt farmers and non-Bt farmers in five major eggplant growing districts in Bangladesh and following their production in the field and sales of their product in the marketplace. Bt eggplant varieties had a 19.6 percent higher average yield and 21.7 percent higher revenue. This amounted to $664 more income per hectare, a princely sum for resource-poor farmers in Bangladesh.

The study also found that Bt eggplant sold at the local markets, either to wholesalers or direct to consumers, fetched a higher price than non-Bt eggplant. Some buyers were prepared to pay higher prices for Bt eggplant because the fruit was less damaged than non-Bt eggplant. 

Surprisingly, 40 percent of the farmers who did not grow Bt eggplant had never heard of it. But when they did hear about it from Bt eggplant farmers, 71 percent said they wanted to grow Bt eggplant the following year.

These new findings agree with earlier studies by Bangladeshi scientists who reported Bt eggplant farmers used 61 percent less insecticide than conventional eggplant farmers and received a six-fold higher return per hectare. Likewise, a report by the International Food Policy and Research Institute demonstrated increased economic returns and revealed that farmers had decreased occurrences of pesticide-related symptoms and the subsequent need to seek medical care.

Taking it to the farmer

Farmers, as we’ve seen, are the best advocates for Bt eggplant. The technology reduces production costs while also reducing hazards to the environment and consumers. Bt eggplant itself has been shown to be safe for humans. When an EFSB larva ingests the Bt protein, it binds to cells in its gut and stops feeding and starves. Humans and most other organisms lack these binding cells, so they are not affected. Bt has a long history of safe use and organic growers routinely spray Bt in an attempt to control caterpillar pests. But spraying Bt is not as effective because total plant coverage and weekly applications are needed. 

Bt eggplant was approved by the Bangladeshi regulatory agencies in 2014 after seven years of greenhouse and confined field trials by the Bangladesh Agricultural Research Institute (BARI) in various geographic locations in Bangladesh to test their efficacy and environmental safety. The new research results show that while Bt eggplant is making progress and finding acceptance in the market, there’s still work to be done. 

The study was conducted by the Feed the Future South Asia Eggplant Improvement Partnership, a project based in Cornell’s Department of Global Development and funded by USAID. Other members of the consortium include the Bangladesh Agricultural Research Institute (BARI), an Indian-based seed company (Mahyco) and Sathguru Management Consultants. 

Other study authors include Sayed H. Sarwer and Md J. Hossain of the Feed the Future South Asia Eggplant Improvement Partnership based at Cornell; Graham Brooks of PG Economics, Stafford House, in the United Kingdom; and Vijay Paranjape of Sathguru Management Consultants Pvt. Ltd., in Hyderabad, India.

About the authors:

• Dr. Anthony Shelton is professor of entomology at Cornell University and former director for the Feed the Future South Asia Eggplant Improvement Partnership based in Cornell’s Department of Global Development. 
• Matt Hayes is associate director for communications for Global Development at Cornell University's College of Agriculture and Life Sciences.
• Joan Conrow is managing editor for the Cornell Alliance for Science.