Davao tests bio agent on durian pest

DAVAO CITY (MindaNews/05 October) – The City Agriculture Office is now testing a biological agent on Phytophtora, a microorganism that attacks high-value crops like durian and slowly kills the host plants.

But Jeanna Massing, field technician in Tugbok District, clarified that not all durian varieties are susceptible to Phytophthora.

The most susceptible of the 16 varieties in the city is the popular Arancillo, Massing said.

“That is the characteristic of Arancillo, very vulnerable to pests particularly Phytophthora, which attacks the bark of the durian and slowly kills it in about a year,” she explained.

Unlike other pests that attack certain parts of the plant, Phytophthora affects the entire tree, the agriculturist said.

Jaenna Masing, field technician of the Davao City Agriculture Office tells how a durian tree can be infected with borer (the black spots on the trunk) at the Cespedes Farm in Tugbok District, Davao City on Tuesday, October 4, 2011. The borer is associated with Phytophthora, a fungus that slowly kills durian trees. MindaNews Photo by Ruby Thursday More To address this problem, Massing said they are now on field trial using Trichoderma species for pest control in one of the durian farms in Barangay Angalan.

She disclosed that around 30 hills of durian have been infested by Phytophthora last year in this one-hectare durian farm.

“The owner had almost abandoned this farm because of the Phytophthora infestation. Now we are conducting our trial here at 15 hills of durian using the Trichoderma and 15 others using synthetic pesticides,” explained Massing.

The Trichoderma, she added, is also a type of fungus that acts like an antibiotic to the tree.

Although some commercial plantations are already using Trichoderma, Massing said this is yet to be maximized and introduced to the farmers starting next year.

The CAO will invite farmers to the trial farm and introduce to them the technology.

She said the Bureau of Soils is now culturing the Trichoderma and will sell them to the farmers for P30 per pack.

“It’s easy to use, just rub them to the bark and it will slowly heal the damaged bark of the durian,” Massing said, adding that it is safe to human health compared to synthetic pesticides.

The technology is in compliance to the Organic Code of the city that limits the use of synthetic pesticides, she pointed out.

Among the signs of infestation are juicy spots on the bark, change of tissue color and yellowing of leaves.

Massing said Trichoderma must be applied during the early stage of the infestation in order to save the plant.

Aside from durian, Phytophthora also attacks cacao, jackfruit and other fruit trees.

Meanwhile, another biological agent is being developed by the CAO to contain pest infestation in corn and high-value crops.

Analyn Jaca, head of the bio-control agent department, said that they are currently testing the effectiveness of the Trichogramma, a tiny Hymenopteran wasp that measures one millimeter in length or less.

Jaca said it takes a month to fully develop the Trichogramma, including its transfer to the cards that will be distributed to the farmers.

These tiny wasps are fed with imported wheat to enable them to reproduce, she said.

Trichogramma wasps are glued on cards with a gaping hole that could fit the leaves of the corn. The card looks like a sand paper when filled with the wasps.

Jaca explained that the Trichogramma wasps attack eggs of parasites like borers.

“This is effective because it attacks the egg of the parasite. So it prevents further infestation because the parasites are already contained in the early stage,” she stressed.

For now, they are giving the cards to interested farmers who want to try Trichogramma wasps in their cornfields.

“A hundred cards is enough for an hectare of corn,” Jaca said, adding it can also be used on other crops. (Keith Bacongco/Mindanews)