Phl may be global forerunner of pesticide-free eggplants

The Philippines stands to be a global forerunner in healthful, pesticide-free growing of traditionally intensively-sprayed eggplant, having been among the world’s top 10 eggplant producers.

Eggplant is the most important vegetable in the Philippines, taking up 30 percent of all vegetable production – at around 200,000 metric tons yearly.

But while known for many gourmet recipes – parmigiana, ratatouille, ome-lette – eggplant is really a vegetable that cannot grow without heavy insecticide spraying.

Filipino farmers spray every other day or 60-80 times in an entire four-month eggplant cropping season. They do this to survive the highly infesting moth “fruit and shoot borer” (FSB), which puts people’s health at risk.

The first at risk are farmers who have confessed to suffering from dizziness, headaches and skin rashes.

With the development by Filipino plant breeders of Bt eggplant that has built-in resistance to FSB, Filipino farmers can do away with pesticide spraying by as much as 100 percent.

Producing the no toxin-laden eggplant is now possible.

Field trial reports released for the first time for public consumption by the Institute of Plant Breeding-University of the Philippines Los Banos (IPB-UPLB) showed Bt eggplant had superior performance in controlling pest FSB.

It involved testing of five open pollinated varieties engineered to produce from the bacterium Bacillus

thuringiensis (Bt) a protein called “Cry1Ac.”

Cry1Ac effectively functions as the insecticide that kills the moth FSB when ingested by the pest.

The experiments were done over three eggplant seasons from 20102012 in the Philippines’ biggest eggplant producer – Pangasinan.

Pangasinan itself accounts for 18 percent of Philippines’ eggplant area and more than 30 percent of the country’s eggplant output.

An ability to stamp out FSB by as much as 100 percent was observed in the Bt eggplant varieties tested on actual fields in barangays Paitan and Sta. Maria in Pangasinan.

These are fields conventionally infested heavily by the FSB moth – more severely during the biggest eggplant season – the dry season.

But IPB scientists did not use any lepidopteran (moth)-specific insecticide during the three trials – both for the Bt eggplant and the non-Bt eggplant.

All throughout three trials, the superior efficacy of Bt eggplant in stopping virtually 100 percent infestation of FSB was observed in the three eggplant varieties tested – Dumaguete Long Purple, Mara, and Mamburao.

All three varieties – unsprayed by insecticides – were planted both for Bt eggplant and non-Bt eggplant.

“These results demonstrate that Bt eggplant lines containing Cry1Ac EE-1 provide outstanding control of EFSB and can dramatically reduce the need for conventional insecticides,” IPB scientists said.

“Bt eggplant lines demonstrated high levels of control of FSB shoot damage (98.6–100 percent) and fruit damage (98.1–99.7 percent) and reduced FSB larval infestation (95.8– 99.3 percent) under the most severe pest pressure during Trial 2.”

The non-Bt eggplant suffered 41.58 percent FSB-damaged shoots, 93.08 percent damaged fruits, and 16.15 larvae per plot per harvest.

And even when moth’s eggs have been found in the Bt eggplant fruits, the eggs did not survive to form viable fruit-boring insects.

Farmers perennially spraying insecticide on eggplants have suffered from endless health complaints as redness of eyes, skin irritation, muscle pains and headaches due to the spray.

FSB has been most notorious for misshaping and destroying eggplant fruits.

Their most destructive damage are the holes, the tunnels they bore within the eggplant along with the frass (larval excrement) they leave in the fruit – making it dirtily unmarketable.

Manual removal of the pest or the damaged fruits and wilted shoots has been found ineffective. The use of arthropods and pheromone traps as biological control has also been found ineffective. Traditional breeding also failed in controlling FSB.

But the control of pests through Cry1Ac expression into the eggplant through the introduction of the human-safe bacterium Bacillus thuringiensis (Bt) has earlier been proven on cotton and corn.

The success of the Bt technology in corn and cotton has been widely accepted globally by farmers .

As of 2014 the Bt technology has been planted on 78.8 million hectares in 28 countries “predominantly by resource-poor farmers.”

Bangladesh became the first country to grow Bt eggplant. It had 20 fields in 2014 and immediately grew to 108 in 2015.