Weeds in Tea

8/11/2019 Weeds in Tea

1/33

WEE S in tea

G.S.Pradeep


2/33

WEEDS

A weed is a plant growing where it is not desired or out of place,that interferes with agriculturists objectives. Weeds include all

types of unwanted plants

TreesBroad Leaf Plants

Grasses

Sedges

Aquatic Plants

Parasitic plants


3/33

Harmful effect of Weeds on Crop

production

Compete with crops for moisture, light, nutrients and space

Reduce quality of products

Choke irrigation canals and reduce water quality

Reduce labour efficiency

Act as a secondary host

Reduce land value

Hazardous to human and animals health


4/33

Characteristics of Weeds

Grow and thrive in different ecological conditions

Reproduce by

Seeds

Stem cuttings

RootsLeaves

Rhizomes

Tubers

Comes

RunnersStolen


5/33

Characteristics of Weeds

Weeds propagules are disseminated via

Human Activities

Wind

Water

Animals and Machinery


6/33

Classification of weeds

Weeds are classified based on

Life Span

Leaf and Stem Morphology

Habitats


7/33

Life Span

a. Annual Life cycle completed within one year

b. Biannual Life cycle completed within two years Flowering

stage only at the 2ndyear

c. Perennial A plant living several years and flowering

occur each year at flowering


8/33

Morphological Characteristics

Grasses

monocot

hollow nodes and solid inter nodes

long slender leavesSedges

monocot

long slender leaves

triangular solid stem

Broad leaveddicots

netted leaf venation


9/33

Weeds Control Methods in Tea

Eradication

Complete removal of weeds from given area

Prevention

Blocking the infestation of weed species in a particular area

Management

Reducing weed density below economic threshold level


10/33

Different Weed Management Techniques

Manual Methods - Hand puling: labour intensive

Mechanical Methods - Mamoting, scraping, etc

Agronomic Methods - Proper bush mgt, infilling, mulching

and shade mgt

Chemical Methods - Use different types of herbicides

Biological methods - This involves the utilization

of natural enemies

Integrated weed mgt - use of two or more above

Mentioned techniques


11/33

Chemical methods

Chemical methods

Pre-emergentApplied on to the bare soil before

weeds emerge

Diuron, Oxyfluorfen

Post emergent

Applied on grown weeds

Contact

Causes scorching on the

aerial part of plant

Systemic

Absorbed by plants roots

moves and kill the plant


12/33

Standard nozzles for herbicide spraying

1. Green Polyjet nozzle

Spray swath up to 90100 cm

Suitable for young and mature tea fields

2. Yellow Polyjet nozzle

Spray swath up to 50cm

Suitable for mature tea fields and spot spraying


13/33

3. Blue Polyjet nozzle

Spray swath up to 1.5m

Suitable for non tea areasEg:-

Ravines

Road banksTimber clearings


14/33

With different crops weeds act in different manner

Some weeds not threatening economically harmful level

This plants naturally grown in an agriculture land gives severalbeneficial effects


15/33

Such as

Prevent soil erosion

Increase soil fertility

Some are use as pastures and fodder

Some medicinal plants

Some human consumption

Some host for beneficial insects

Substitutes for pesticides

Some are fix N


16/33

Ageratum conyzoides

Sinhala - hulantala

Tamil - Poom pillu

English - White weed/ billygoat weed

Life cycle - Annual herb

Propagation - by seeds

Control measures - Use of herbicides


17/33

Amaranthus v i r ids

Sinhala - Kurathampala

Tamil - araikkirai





18/33

Anredera co rdi fo l ia

Sinhala - Val nivithi

Tamil - pasali kodi

Life cycle - Perennial

Propagation - by vegetative bulbils,

by even small cuttings

Control measures - Manually/ dip these

weeds in glyphosate


19/33

B idens pi losa

Sinhala - Val te kola / letiya

Tamil - ottu pillu





20/33

Centella asiatica

Sinhala - Heen gotukola

Tamil - Vallari

Life cycle - Perenial

Propagation - vegetatively



21/33

Commel l ina Diffusa

Sinhala - Girapala/ diya meneriya

Tamil - Amali

Life cycle - PrennialPropagation - by vegetative/seeds



22/33

Crassocephalum crepid io ides

Sinhala - Kadupahara

Tamil - keera thandupillu

Life cycle - AnnualPropagation - by seeds



23/33

Emil ia sonchi fo l ia

Sinhala - Kadupara

Life cycle - Prennial

Propagation - by seedsControl measures - Use of herbicides


24/33

Erigeron sumatrensis

Sinhala - Sudana

Tamil - Alawangu pillu, cochi poom pilu




25/33

Ipomoea ind ica

Sinhala - Valbatala

Life cycle - Annual

Propagation - by Stem/seedsControl measures - Use of herbicides


26/33

Mimosa pudica

Sinhala - Heen Nidikumba

Tamil - thotat sinungi




27/33

Oldenlaland ia co rymbosa

Sinhala - Wal-path padagam/Papiliya

Life cycle - Annual




28/33

Osbeck ia oc tand ra

Sinhala - Heen bovitiya/ Kuruwina

Tamil - Kathtoo mukhtohulai/ Mahthulai

Life cycle - Perennial

Propagation - by Seeds



29/33


30/33

Vernon ia cin erea

Sinhala - Monara kudumbiya

Tamil - Neisudi kirai

Life cycle - Annual




31/33

Cynodon dacty lon

Sinhala - Durva

Tamil - arugampillu

Life cycle - Peranial

Propagation - by Vegetative/Seeds



32/33

Ech inochloa co lona

Sinhala - Goda maruk

Tamil - Adi pul

Life cycle - Annual




33/33

Weeds in Tea

Documents

Transcript of Weeds in Tea