THE PHILIPPINE Center for Postharvest Development and Mechanization (PhilMech) said it is studying how to reduce losses in the sweet potato harvest to reduce damage to the produce, which depresses the prices farmers can obtain.

According to a study by the agency, postharvest losses for sweet potato range from 31.21% to about 33% due to “inefficiency of existing manual and labor-intensive harvesting methods.”

“The harvesting operation of sweet potato can be mechanized using an efficient mechanical root crop harvester that can eventually reduce labor requirements and losses on uncollected roots,” PhilMech added.

PhilMech said sweet potato is the seventh most important crop in the world, and the third most important in the Philippines after rice and corn. It is usually planted to tropical and sub-tropical countries, specifically in areas with less productive soil.

A typical harvest requires 30 to 50 workers per day over two days, leading to significant crop damage, lowering the viability of the future crop.

“Harvest losses due to uncollected and mechanically-damaged roots ranged from 15.96 %to 17.94 % of the marketable harvest,” the agency said, adding that other losses are due to the transportation of the harvest from farm to market.

At the farmer level, the average postharvest loss is 16.95% and 0.82% in losses of unharvested crops. At the wholesale level, 3.93% of postharvest losses are due to cleaning and rebagging, which largely eliminates the weight of the peel. At retail, 10.39% of postharvest losses are reported due to spoilage.

PhilMech is evaluating a tractor-drawn device developed by the Philippine Root Crop Research and Training Center at Visayas State University in Leyte and has recommended its commercialization.

According to the Philippine Statistics Authority sweet potato output increased 1.4% to 134,060 metric tons (MT) in the third quarter, with Eastern Visayas accounting for the bulk of production at 35.2% or 47,220 MT. This was followed by Bicol Region (11.3%) and Caraga Region (9.1%). — Vincent Mariel P. Galang