|Tocklai Tea Research Institute
Guwahati, Aug. 8: Tocklai Tea Research Institute is now advocating non-chemical management of pests, which involves control techniques that do not rely on the use of pesticides.
The non-chemical management of pests is adopted in organic cultivation as well as in situations where the introduction of toxic chemicals is neither desirable nor admissible. “This is for the first time that the non-chemical management of pests is being advocated for the industry. There is a consolidated document available on it which the industry can refer,” N. Muraleedharan, director, Tocklai Tea Research Institute, told The Telegraph.
He said though the industry has been using chemicals to control pests, there are various problems attached to it.
A total of 33 pesticides are permitted by the Central Insecticides Board (CIB) for use on tea in the country. On an average, a garden spends Rs 8,000 per hectare on pest control measures and this can go up when pest infestation becomes huge.
Another official of Tocklai said instead of using pesticides, pest control is achieved by biological or other means. “In a garden, the management should analyse the field situations relating to plant health, weather parameters, occurrence of pests and the activities of natural enemies of pests to evolve non chemical control strategies,” the official said.
The manual on non-chemical management says field scouting should be done to monitor the initial pest build up in each section of the garden. Based on the findings of field monitoring, the management has to concentrate on the adoption of non-chemical control tactics.
“This does not require high technology and can be done easily,” he said.
With reference to the tea mosquito bug (Helopeltis theivora), the percentage of infestation has to be assessed by collecting 100 shoots from a plucker’s basket and counting the number of infested and non-infested shoots to work out the percentage infestation.
“A closer plucking schedule helps to remove inserted eggs and early nymphs of the tea mosquito bug, before they cause more damage,” the manual said. For controlling red spider mite, the manual advised planting of shade trees as spacing will reduce mite build-up. “The bushes along the motorable roads, which remain covered with dust, are very often severely attacked by red spider mite. The roadside bushes can be protected by growing hedge plants like Phlogacanthus thyrsiflorus (titaphool). Applying water on the dusty roads at regular intervals is a good practice for management of red spider mite,” it stated.
To prevent migration of red spider mites, the movement of pluckers from the infested areas into non-infested areas should be stopped. Cattle trespass into tea sections should also be stopped. The bushes in ill-drained or waterlogged areas are subject to increased red spider mite damage, than those in well drained areas. “Inadequate drainage is not only harmful to the tea plants but also creates conditions conducive to the build-up of red spider mite,” the manual said.
In the case of looper caterpillar, the caterpillars can be removed manually and removal of weeds in an around the tea sections should be done.