Journal of Zhejiang University SCIENCE B
ISSN 1673-1581(Print), 1862-1783(Online), Monthly

2009   Vol. 10   No. 6   p. 422~426

Contribution of leaf growth on the disappearance of fungicides used on tea under south Indian agroclimatic conditions

Chinnachamy KARTHIKA^†, Narayanan Nair MURALEEDHARAN

(United Planter’s Association of South India (UPASI) Tea Research Institute, Tea Research Foundation, Nirar Dam B.P.O, Valparai 642 127, Tamilnadu, India)
^†E-mail: kartheecm@rediffmail.com
Received Jan. 22, 2009; revision accepted Apr. 27, 2009; Crosschecked Apr. 30, 2009

Abstract: The sprayed chemicals on tea leaves disappear over a period of time by the influence of rainfall elution, evaporation, growth dilution, and photodegradation. Influence of plant growth on the four fungicides (hexaconazole, propiconazole, tridemorph, and c) was studied to know the constructive loss of fungicides. The study shows that residues of fungicides sprayed on tea shoots got diluted by the growing process. The expansion of a leaf took 8 to 11 d and more than 50% of the fungicide residues were cleaned out during this leaf expansion period. Under south Indian agroclimatic condition, the fungicides are sprayed at an interval of 10 d, so it is safe that the tea is harvested on the 10th day of the application of fungicides.

Key words: Tea shoots, Growth, Dilution, Fungicides, Residue loss
doi:10.1631/jzus.B0920026             CLC number: S571.1; S482.2

References:

[1] Angioni, A., Aguilera Del, R.A., Russo, M., Melis, M., Cabitza, F., Cabras, P., 2003. Triazole fungicide degradation in peaches in the field and in model systems. Food Additives and Contaminants, 20(4):368-374.

[2] Chen, Z.M., Wan, H.B., 1997. Degradation of pesticides on plant surfaces and its prediction—a case study on tea plant. Environmental Monitoring and Assessment, 44(1/3): 303-313.

[3] Garland, S.M., Menary, R.C., Davies, N.W., 1999. Dissipation of propiconazole and tebuconazole in peppermint crops (Mentha piperita (Labiatae)) and their residues in distilled oils. Journal of Agricultural and Food Chemistry, 47(1):294-298.

[4] Garland, S.M., Davies, N.W., Menary, R.C., 2004. The dissipation of tebuconazole and propiconazole in boronia (Boronia megastigma Nees). Journal of Agricultural and Food Chemistry, 52(20):6200-6204.

[5] Groenewoud, K.M., Davies, N., Menary, R.C., 1995. Determination of propiconazole residues in boronia extract. Journal of Agricultural and Food Chemistry, 43(5): 1230-1232.

[6] Karthika, C., Sachin, P.J., 2008. Gas chromatographic method for the determination of hexaconazole residues in black tea. Journal of Zhejiang University SCIENCE B, 9(2): 160-164.

[7] Karthika, C., Muraleedharan, N.N., 2009. Residual deposits in green tea shoots and black tea after individual and combined application of propiconazole and copper oxychloride. Journal of the Science of Food and Agriculture, in press.

[8] Muraleedharan, N., 1991. Pest Management in Tea. The United Planter’s Association of Southern India, Tea Research Institute, p.1-108.

[9] Murthy, R.S.R., Sharma, V.S., 1989. Rationalisation of plucking intervals in tea. UPASI Tea Scientific Department Bulletin, 43:6-15.

[10] Premkumar, R., Baby, U.I., 2005. Blister blight control—a review of current recommendations. Journal of Plantation Crops, 101(5):26-34.

[11] Radhakrishnan, B., Baby, U.I., 2004. Economic threshold level for blister blight of tea. Indian Pytopathology, 57(2): 195-196.

[12] Schermerhorn, P.G., Golden, P.E., Krynitsky, A.J., Leimkuehler, W.M., 2005. Determination of 22 triazole compounds including parent fungicides and metabolites in apples, peaches, flour, and water by liquid chromatography/tandem mass spectrometry. Journal of AOAC International, 88(5):1491-1502.

[13] Sharma, V. S., 1979. Growth rhythm of tea shoots. UPASI Tea Scientific Department Bulletin, 36:9-11.