Experiments were carried out to evaluate the toxicity of six botanicals, Bazna (Zanthoxylum rhetsa), Ghora-neem (Melia sempervirens), Hijal (Barringtonia acutangula), Karanja (Pongamia pinnata), Mahogoni (Swietenia mahagoni) and Neem (Azadirachta indica) against red flour beetle, Tribolium castaneum Herbst. Leaf and seed extracts were prepared by using acetone, methanol and water as solvents. The results showed that extracts of all the six plants had direct toxic effect on red flour beetle. Among them, Neem seed extract showed the highest toxic effect (mortality, 52.50%), whereas Hijal leaf extract possessed the lowest toxic effect (mortality, 22.24%). Among the solvents, acetone extract showed more toxic effect than other extracts. Seed extracts of respective plants were slightly more toxic than leaf extract. The effectiveness of most of the plant extracts increased proportionally with the increase of doses and decreased with time.

Tea is a popular beverage made from the leaves of evergreen shrub or tree Camellia sinensis, under the family Theaceae. Tea plant is subjected to the attack of insects, mites, nematodes and some plant pathogenic diseases. Tea production is greatly hindered due to these maladies. About 10-15% crop loss occurred by these pests per annum. In severe cases, it would be 100%. To combat these problems different groups of pesticides have been used in the tea fields since 1960. As tea is a consumable commodity, the effect of residue of pesticides in made tea is harmful to human health. In this context, biopesticides are being considered as environmentally safe, selective, biodegradable, economical and renewable alternatives for use in IPM programmes. Biopesticides are natural plant products and may be grown by the planters with minimum cost and extracted by indigenous methods. Biopesticides are secondary metabolites, which include alkaloids, terpenoids, phenolics, and minor secondary chemicals. It is estimated that as many as 2121 plant species have been reported to posses' pest control properties. Botanicals like neem, ghora-neem, mahogoni, karanja, adathoda, sweet flag, tobacco, derris, annona, smart weed, bar weed, datura, calotropis, bidens, lantana, chrysanthemum, artemisia, marigold, clerodendrum, wild sunflower and many others may be grown by planters with minimum expense and extracted by indigenous methods. These botanical materials can be used as an alternative to chemical pesticides. These botanical extracts will help in controlling major pests of tea such as Helopeltis, red spider mite, aphids, thrips, jassid, flushworm, termites, nematodes etc. The present note reviews the information of most widely available indigenous plants that may be used for the control of insect pests of tea as a component of IPM.

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Laboratory experiment was conducted to study the biochemical and quality parameters of tea i.e. Polyphenol, Theaflavin (TF), Thearubigin (TR), Caffeine, Lipid, Total ash, Chlorophyll, Moisture content etc. under different variables designed for age, topography, and processing system imposed on an established tea orchard. Results revealed that plant age and topography do not have any significant effect on most of the studied parameters. In case of plant age, tannin is found to be significantly higher in mature tea plant (39.35 ppm) whereas young plant showed significantly lower total sugar content (28.98 ppm). In case of land elevation, significantly higher tannin (37.41 ppm) and lower carotenoid content (0.74 mg/g) were evident in plants from kunchi topography where flat topography showed significantly higher total sugar (26.62 ppm) in leaves. The handmade tea flavoured with significantly higher amount of polyphenol (58.57 ppm) and caffein (43.30 ppm) but industry made tea showed significantly higher amount of tannin (37.65 ppm), total sugar (15.25 ppm) and TF:TR (1:10). Bangladesh J. Bot. 50(3): 633-639, 2021 (September)