New pest control for jatropha found

MANILA, Philippines - Researchers of the Tarlac College of Agriculture have discovered new pest control for jatropha curcas, which is now being propagated all over the country for biofuel production.

The researchers, led by Dr. Manuelo Agsaoay, came up with biological control agents by studying for three years insect pests attacking jatropha curcas.

The assessment of critical pest damage showed that of the five identified insect pests attacking jatropha, three were confirmed as major pests — mealy bugs, aphids, and cutworms.

Agsaoay and his colleagues determined the efficacy of the coccinelid beetle as a predator of both aphids and mealy bugs.

According to the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD), aphid mortality gradually increased over three weeks and reached 28 percent in one treatment.

Concurrently, leaf damage resulting from aphid feeding was only slight, it added.

“On the other hand, the coccinelids significantly reduced the population of mealy bugs after only one week from release. As with the aphids, mortalities of mealy bugs increased slightly as feeding exposure increased,” the PCARRD said.

In addition, prey populations decreased significantly as predation mortality values ranged from 50 percent to 60 percent, it said.

Meanwhile, another study found that jatropha does not hinder the reproduction of beneficial bacteria such as aerobic heterotrophs, free-living nitrogen fixers, and pseudomonads.

Behind study were researchers Marilyn Brown and Virgilio Villancio of the National Institute of Molecular Biology and Biotechnology and the Agricultural Systems Cluster of University of the Philippines Los Baños’ College of Agriculture.

Their research showed that the plant encouraged fungal growth as proven by more vesicular arbuscular mycorrhizal fungi found in soil planted with jatropha.

Jatropha is considered as the best source of biofuel among the various plant-based fuel resources worldwide.

Jatropha curcas is a drought-resistant plant and has wide adaptability to varied climates and types of soil. Its seeds contain viscous oil of about 28 to 35 percent.