Transcript NAME: ODONGO MESO HILDA REG NO: A22/0070/2009 BSc

NAME: ODONGO MESO HILDA
REG NO: A22/0070/2009
BSc AGRICULTURE (Crop Protection)
SPECIAL PROJECT PROPOSAL PRESENTATION ON:
THE EFFECT OF SELECTED HERBICIDES ON WEED
SPECIES IN COFFEE
SUPERVISER: PROFESSOR RATEMO MICHIEKA
INTRODUCTION

Coffee is one of the world’s largest traded
commodities produced in more than 60
countries, providing a livelihood for some
25,000,000 coffee farming families around the
world.

The coffee sub-sector in Kenya is one of the
major employers and contributed about 5% of
export revenues in 2003.The national area under
coffee is estimated at 170,000 hectares. Coffee is
grown between altitude 1,400 and 2100 meters
above sea level.
Problem Statement
A large number of annual and perennial weeds infest coffee
plantations. Tropical climates with ample sunshine, heat and
moisture mean that weeds thrive and may compete with
crops for space, water and nutrients, and shade the crop
plants, especially when they are young. (Friesslenben et
al…1991)
 Weeds significantly reduce yield, make farm operations
difficult and could even be toxic to livestock, all these in turn
result in economic losses.
 Small scale farmers most of the time have capital constraints
this translates to inappropriate use of herbicides or
continous use of readily available herbicides without
appropriate education on application rates, frequency of
application and stage of application, All these practices could
lead to a shift in weed species in coffee plantations or
development of resistance to herbicides.

Justification
Historically, coffee has been an important commodity in
Kenya because of its contribution to foreign exchange
earnings, farm incomes and employment opportunities. Prior
to 1988, coffee was Kenya’s leading foreign exchange earner
and currently ranks fourth after tourism, tea and
horticulture, accounting for 10% of the total export earnings
in the year 2000 and 6% in 2001. Over 600,000 smallholders
are engaged in coffee production and currently command a
48% share of the market.
 Earnings from coffee are important as they increase the
purchasing power of small holder farmers thus enhancing
their economic status.
 The study finds out to what extend weeds affect coffee
production, and ways in which production can be increased
through efficient weed control.

Objectives
Overall objective
 To find out the effect of long-term use of paraquat and glyphosate
on weed populations in coffee
Specific objective
 To find out the challenges faced on the use of Paraquat and
glyphosate in terms of weed shift and weed resistance, the amount
farmers use and the frequency of use, time of use in terms of stage
of growth on both weeds and the crop is also of importance
Null Hypothesis
 The long term use of paraquat and glyphosate results in a shift of
weed species in coffee
Alternative Hypothesis
Long term use of paraquat and glyphosate has no effect on weed
species in coffee.
Weeds as a Constraint in
Coffee Production
Weeds are a serious problem in many
crops including coffee both in nurseries
and established orchards, a large number
of perennial and annual weeds infest
coffee plantations,
 Weeds commonly found in coffee include

Common name
Botanical name
Black Jack
Bidens pilosa
Pig weed
Amaranthus sp
Gallant soldier
Galisonga parviflora
Mexican marigold
Targetes minuta
Black night shade
Soalanum nigrum
Parthenium
Parthenium hysterophorus
Wood sorrel
Oxalis sp
Wandering jew
Commelina sp
purslane
Portulaca oleracea
Nut grass
Cyperus sp
Wild finger millet
Eleusine indica
Love grass
Setaria verticillata
Kikuyu grass
Penisetum clandestinum
Star grass
Cynodon dactylon
Couch grass
Digitaria scalarum
Common Weed Management
Practices in Coffee
Shade
 Hand Hoeing and Mechanical Tillage
Implements
 Slashing
 Cover crops
 Mulch
 Herbicides (glyphosate, Paraquat)

Glyphosate


Glyphosate (N-(phosphonomethyl) glycine)
is a non-selective broad-spectrum systemic
post emergence herbicide that has been
used extensively throughout the world over
the past three decades.
It inhibits the biosynthesis of aromatic amino
acids (phenylalanine, tyrosine and
tryptophan) which leads to several metabolic
disturbances including inhibition of protein
and secondary product biosynthesis
Paraquat

paraquat is a quick acting herbicide that
destroys green plant tissue by contact
action and some translocation, it is rapidly
and tightly bound to soil, it is used to
control broad-leaved weeds and grasses,
being less effective on deep rooted plants
such as dandelions.
Weed shift and resistance
Shift-Refers to a change in the relative
abundance or type of weeds as a result of
management practices such as herbicide use,
which brings about a change in weed species
composition.
 Resistance-changes in response to herbicide
use and other management decisions. a small
number of plants within a species, called a
“biotype,” have a distinct genetic makeup
that allows them to tolerate a particular
herbicide application. Multiple weed biotypes
can exist in a single field.

Materials and Methods

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Data will be collected by means of a questionnaire
administered to farmers, a sample of 30-40 farmers will be
questioned in Kiambu County which is one of the major
coffee producing areas in the country.
Questions to be asked include but are not limited to;
-the length of time in years that the farmer has produced
coffee
-general trends in yield of coffee in the farm
-weeds present and prevalent in the farm
-methods of weed control
-herbicides used in weed control
-if there has been observed changes in weed species over
time.
Data collected will be analyzed using SPSS package (Version
19).
Work Plan
MARCH
Project proposal
writing and data
collection
Project proposal
presentation and
data analysis
Report writing
and project
presentation
APRIL
MAY
Budjet
Printing Questionnaires
500
Transportation costs to kiambu
3000
Miscellaneous
500
Total
4000
References
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Akobundu I.O 1987 Weed science in the Tropics Principles and
Practices John Whiley and Sons New York 522 pp
Coffee cocoa and tea K.C. Wilson
Coffee the Plant the Product Rene Coste
Monsanto Agricultural Company, Chesterfield, MO 63198.
Nishimoto, R.K Evaluation of Pre emergence Herbicides for
Establishing Coffee
Njoroge, J.M.E, Mwakha, 1983 Observation of the Effects of
Weeding and Cover Crops on Coffee Yield and Quality
Tropical Pest management,Volume 21, Issue 1, March 1975 pg 58-63
Weed Management for Developing Countries R.Labrada, J. C.
Casely