Biotechnology product Bt eggplant will bring health cost savings of P9.33 million yearly from its nearly pesticide-free use, benefitting not only health of consumers but especially of farmers, beneficial insects, farm animals, and birds, a study showed.

Biotechnology product Bt eggplant to bring P9.33 million yearly health costs savings, benefitting consumers’ and farmers’ health, beneficial insects animals, birds 1

The “Health and Environmental Impacts of Bt Eggplant” by Sergio R. Francisco has estimated savings in a survey of long exposed to pesticide spraying against the highly-infesting moth fruit and shoot borer (FSB).

It was based on the perception of 100 eggplant farmers from Batangas, Pangasinan, Quezon, and Nueva Ecija who sprayed their eggplant from a lengthy farming experience of 9.96 to 18.04 years.

Given the start of growing Bt eggplant, benefit to human health from health cost savings is equivalent to P2.49 million yearly as risk from illnesses is avoided.

For farm animals, projected benefit per year is at P2.12 million.

For beneficial insects, environmental benefit is valued at P2.45 million yearly and for avian species, P2.27 million – as these are saved from death, thereby contributing to biodiversity enhancement ( such as bees that prop pollination and growth of plants).

The study on environment benefit valuation was done based on the Willing to Pay (WTP) model.

Farmers were asked how much higher amount they were willing to pay (WTP) in order to eliminate pesticide  spraying and avoid its health and environmental costs.

The farmers indicated that they are willing to pay a higher price by up to P1,019 per liter for a safer pesticide for human.

They also assured willingness to pay an additional P945 per liter for farm animals’ safety and by a higher P894 per liter for those safer for beneficial insects.   For pesticides safer for birds, they are willing to pay P867 per liter more.

The estimated benefits are realized based on an assumed  Bt eggplant growing on 50% of present eggplant area of 9,000 hectares with a farm area each of 0.7 hectare.

Francisco also employed Kovach’s universal indicator for Environmental Impact Quotient (EIQ) —  mixing different adverse environmental impact of pesticides as one value per hectare.

It accounts for all toxicity and environmental exposure data.  Simply, EIQ represents the negative environmental footprint left by pesticides.

Since farmers growing Bt eggplant use only 6.22 liters of pesticides compared to 11.98 liters per hectare for non-Bt eggplant, down by 48%, EIQ of Bt eggplant is lower too.

“The field EIQ for the non-Bt eggplant was 245 per hectare while that of Bt eggplant was around 198, equivalent to a 19.5% reduction in environmental footprint,” said Francisco.


Farmers across the four eggplant-producing provinces also rated risks of pesticides on the four environmental categories (human, animals, birds, and beneficial insects).

The risk scores were highest on the adverse impact to beneficial insects—a rating of 5 for most pesticides including betacypermethrin, carbaryl, carbofuran, cartap HCL, chlorpyrifos,cypermethrin, lambdacyhalothrin, and malathion.

For risks to birds, pesticides that were rated with highest risk score at 5 by farmers were carbofuran, Chropyrifiros + BPMC, chlorpyrifos,chlorpyrifos + cyper,and imidacloprid.

For risks to human, highest score of 4 was given to betacypermethrin, cypermethrin, and malathion.

For risk to animals, those that got the highest score of 4 were betacypermethrin, cypermethrin, deltamethrin, dimethoate, and Malathion.

Farmers’ sickness

Eggplant farmers are generally aware of the adverse effects of pesticides to human and the environment.

Almost half of the 100 farmers, 46%, admitted to have suffered sickness after pesticide spraying.  Among their complaints were dizziness, nausea, shortness of breath, loose bowel movement, and itchiness.

In Batangas , 88% or 22 farmers  acknowledged they know the adverse effect of pesticide on human health; 56% or 14 said yes when asked about its harm to beneficial insect.

The next highest harm of pesticides was perceived on beneficial insects where farmers who said yes totaled to 19 (76%) in Pangasinan; 14 (56%) in Batangas; 21 or 84% in Quezon, and 22 (88%) in Nueva Ecija.

A total of 18 farmers (72%) believed on its harmful effect against farm animals and 11 or 44% agreed to its negative effect on birds.

In Pangasinan,  the same data was observed where 12 or 88% knew of pesticides’ harmful effect against human health.

In Quezon,  farmers agreeing to pesticides’ harmful effect on human was even higher at 24 or 96% while in Nueva Ecija, 21 farmers (84%) said “ÿes” to pesticides’ adverse effect on human health.

 Yield decline

The worse part is even if farmers have been heavily spraying on eggplants, yield has declined.

Eggplant yield as of a noted 2007 study  was at 18.04 metric tons (MT) per hectare in Batangas, down from the previous five-year average of 25.78 MT per hectare.

The same decline in yield was observed in Pangasinan with 25.05 MT per hectare yield compared to 29.7 MT the previous five-year average.

In Nueva Ecija, yield was lower at 22.3 MT per hectare compared to 24.04 the previous five-year average.

Such trend has caused farmers to intensify pesticide spraying—as pests became more intensively pestilent.

Batangas farmers sprayed at a cost of P31,463 or 19.97% of total production cost for a total of 74.24 liters; Pangasinan, P17,383 (25.66%) using 42.13 liters; Quezon, P29.592 (36.48% ), 79.05 liters; and Nueva Ecija, P33.099 (34.21 %), 62.96 liters.

“Farmers’ pesticide usage would decline by 48% (with Bt eggplant), contributing to a significant reduction in the health and environmental impacts of pesticide use. These reinforce the need for continued support for the development, commercialization, and promotion of Bt eggplant,” said Francisco.

Pertinent spraying

Farmers resort to intensive pesticide spraying as yield losses from FSB ranges from 42-92%, a study of Navasero showed.

Francisco noted 60% of Bangladesh farmers spray their eggplant 140 times within 6-7 months; Filipinos spray every other day or 60-80 times in four months.

Most pesticides are of broad spectrum and “act and interfere with the fundamental biochemical and physiological processes that are common to a wide range of organisms, including humans,” according to Francisco.

Use of toxic chemicals can kill beneficial insects, cause environmental pollution, lead to pest resistance and resurgence, and create hazards to humans, animals, fish, and wildlife.”  (Growth Publishing for BIC)

For any questions or interview requests, please contact 0929-715-8669 (Growth Publishing for Biotechnology Information Center)