Document Type: Original Article

Authors

Department of Agronomy, Forages and Grassland Management, College of Agriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur 176062, HP, India

Abstract

Glyphosate is an effective post emergence herbicide for weed control in tea. However, dose and timing of any new formulation need to be evaluated before being its recommendation to the growers. The weed flora of the experimental field was composed of Ageratum conyzoides (21.9%), Ageratum houstonianum (21.3%), Chromolaena adenophorum (13.0%), Bidens pilosa (9.6%), Lantana camara (6.2%), Cynodon dactylon (6.0%), Fragaria vesca (5.6%), Imperata cylindrica (5.2%), Polygonum alatum (5.1%) and Erigeron canadensis (5.1%). The new formulation glyphosate 71% SG was found to be comparable to the existing formulation glyphosate 41% SL against Ageratum conyzoides, A. houstonianum, Chromolaena adenophora, Bidens pilosa, Fragaria vesca, Polygonum alatum, Erigeron canadensis, Imperata cylindrica and Cynodon dactylon in reducing their population upto 120 days after application (DAA). Glyphosate 71% SG did not show any toxic symptoms on tea crop and tea leaf yield was similar as under standard formulation used in the present study. Glyphosate 71% SG (ammonium salt) sprayed at 6 kg/ha gave highest tea leaf yield (1940 kg/ha) which was statistically similar to the Glyphosate 71% SG (ammonium salt) applied at the rate of 3 kg/ha (1895 kg/ha). It was also comparable to the market sample. Uncontrolled growth of weeds even for a one season reduced tea leaf yield by 48.5%. The bulk density, water holding capacity, moisture content, soil pH, electrical conductivity, available NPK and organic C were not influenced significantly at harvest. The test herbicide glyphosate 71% SG and the market sample glyphosate 41% SL had increased the population of total bacteria, fungi and actinomycetes at harvest over their initial population. However, there was a slight decrease in the population of this microflora immediately after the application of herbicide not due to the herbicide but owing to seasonal variation as the differences between treatments were not significant.

Keywords

Bose A, Ravikumar A, Roy S.B. 2007. Integrated weed management to control Pteridium spp. and Polygonum chinensis in young tea plantations of India. In: Proceedings of 21st Asian Pacific Weed Science Society Conference held at Colombo, Sri Lanka w.e.f.  2-6 October  pp 565-567.

Chauhan P.T. 2015. Kangra tea to get Europeon GI tag soon. News Service Shimla, May 19.

Ilango R.V.J, Saravanan M, Parthibaraj R, Kumar P.M. 2010. Evaluation of Excel Mera-71 for weed control in tea fields. Newsletter - UPASI Tea Research Foundation. 20(1): 1.

Kgawa Y.M, Fredrick C.N. 2015. Survey of Weeds on Tea (Camellia sinensis L. Kuntze) Plantations on the Mambilla Plateau in Nigeria. Global Advanced Research Journal of Agricultural Science. 4: 900-904.

Kumar A, Ghosh R.K. 2015. Bioefficacy of glyphosate for management of Weeds in Tea. 25th Asian-Pacific Weed Science Society Conference on “Weed Science for Sustainable Agriculture, Environment and Biodiversity”,Hyderabad, India during 13-16 October, 2015: p 377.

Kumar A, Ghosh A, Mondal D, Ghosh R, Bandopadhyay P. 2017. Bio-efficacy of ammonium salt of Glyphosate 71% SG for weed dynamics in tea (Camellia sinensis L.) and its effect on soil microflora. Int J Current Microbiol Appl Sci.6: 2160-2170.

Kumar S, Rana S.S, Angiras N.N, Ramesh. 2014. Weed management in tea with herbicides mixture. Ind J Weed Sci.46: 353-357.

Matthew L, Nicola L, Jyotisina S, Cliff R, Richard P.D. 2012. The effect of glyphosate on soil microbial activity, microbial community structure and soil potassium. Int J Soil Biol.55: 335-342.

Mehdizadeh M. 2019. Sensitivity of oilseed rape (Brassica napus L.) to soil residues of imazethapyr herbicide. International Journal of Agriculture, Environment and Food Sciences. 3: 46-49.

Mirghasemi S.T, Daneshain J, Baghestani M.A. 2012. Investigating of increasing glyphosate herbicide efficiency with nitrogen in control of tea weeds. International Journal of Agriculture and Crop Sciences. 4: 1817-1820.

Paul B.V.D, Pierre B.J. 2012. Evaluation of the efficacy of herbicides in tea (Cammelia sinensis) production in Rawada. Int J Appl Agric Res. 7: 197-202.

Prematilake K.G, Froud-Williams R.J, Ekanayake P.B. 2004. Weed infestation and tea growth under various weed management methods in a young tea (Camellia sinensis [L.] Kuntze) plantation. Weed Biol Manag.4: 239-248.