Ultrasound-assisted tapping of latex from Para rubber tree Hevea brasiliensis

- A novel ultrasound assisted rubber yield promotion technology.
- Ultrasound treatment of 4 min significantly increases latex and dry rubber yields.
- Ultrasound enabled higher supply and uptakes of sucrose for more active rubber biosynthesis.

Para rubber tree, Hevea brasiliensis, is a major commercial source of natural rubber that has been extensively used to manufacture high quality rubber products. It is important to develop a safe and efficient latex harvest technique associated with suitable stimulation for high and sustained rubber yields. This work investigates an innovative rubber yield stimulation technology, using ultrasound as a pre-treatment on the tapping cut surface of the rubber trees. The field trial results demonstrate that ultrasound treatment of 4 min can increase latex and dry rubber yields by 23% and 14%, respectively, on an average of 50 replications which is similar to Ethrel stimulation. Unlike the Ethrel stimulation which increases the latex fluidity through dilution, ultrasound treatment may have also enabled higher supply and uptakes of sucrose for more active rubber biosynthesis, as evidenced from the sonication induced changes in sucrose and inorganic phosphorus contents. However, a decrease in thiols content in ultrasound treatment is notable. This ultrasound technology may also be useful for the stimulation of other latex, juice, and paint producing plants.