Insect Infestation in Assam
Damage from attack by scale insects
INDIA
Eastern Assam is experiencing the unwanted return of scale, an insect that defoliates tea bushes.
A. K. Barooah, director of the Tocklai Tea Research Institute (TTRI) told STiR that “Scale recently has created a serious problem in some of the tea estates in eastern Assam.”
A sap-sucking pest, scale is a silent killer if not noticed in time. The insect is mostly active on branches inside the bushes where damage is not easily seen. The insect pierces the plant tissues with its thread-like mouth sucking branches dry. Widespread infestations can lead to velvet blight.
The worst part is that the attack is seen more in quality tea clones used in the production of orthodox tea, he said. “Clones like TV1, Teenali 17, TA 17/1/54 and P126 are more prone to scale infection,” he said.
Tea gardens in the Dibrugarh, Golaghat, and Tinsukia districts are cautioned to be extra vigilant. Defenses include alkaline wash, bush sanitation, shade management, and proper drainage. The body of the insect is covered in a waxy substance that limits penetration of water-based pesticides.
Scale is normally limited by beneficial predators and parasites but due to climate change and over-dependence on synthetic pyrethroids, gardens have experienced a reduction in natural predators, explains Barooah. “We are researching ways to get rid of this pest and have already recommended a few to the tea gardens,” he said. These include drenching the infested plants including all branches up to the collar region and mixing agro spray oil with insecticides to enhance efficacy. “A recent study conducted by TTRI revealed that a combination of aloe vera extract and Himalayan salt has shown promising results in reducing scale,” he said.
– Pullock Dutta