TO STOP spread of cassava witches' broom in the region, the Department of Agriculture (DA) Northern Mindanao has heightened its drive to curb the spread of Cassava Phytoplasma Disease (CPD), which is threatening to affect regional cassava production.

Northern Mindanao produces a quarter of the country's total cassava production amounting to P1.48 billion last year.

Larry E. Paraluman, of DA-Northern Mindanao, said there is a need to raise farmers’ knowledge on how best to fight the disease especially in Bukidnon, which accounts for a big chunk in cassava production in the region.

"We will conduct massive forums in the provinces so that farmers will know what to plant and what not to plant to void the spread of this disease," Paraluman said.

The disease is caused by hytoplasmas, which are specialized bacteria recently assigned to the novel genus Candidatus phytoplasma, meaning without cell wall, in the class Mollicutes, that inhabit plant phloem tissue and insects. More than 600 diseases caused by phytoplasma are recorded in several plant species including cassava, according to the Bureau of Agricultural Research (BAR).

The effects of the diseases of the phytoplasmas range from mild to catastrophic in which up to 100 percent of areas planted are destroyed.

Plants infected with phytoplasma show different symptoms such as stunted growth and shoot proliferation that is either chlorotic or with excessive anthocyanin pigmentation. Roots from infected plants are small with rough, textured skin and brown-streaked flesh. Older plants show symptoms of die-back and reduced yield, data from BAR show.

CPD can cause yield reduction to about 50-70 percent when disease symptoms appear during the mid-part of the growing season and even 100 percent when infection starts during the first three months from planting date. High humidity and warm temperature favor the disease’s development, the BAR said.

"This disease will only disappear if farmers stop planting which is impossible. Farmers should pay attention in choosing planting material” Paraluman said.

Paraluman said the DA is closely monitoring the entry and exit of cassava planting materials in the region.

Paraluman furthered the DA is already identifying all the areas infested with the disease, expecting to finish the survey by month end.