Weed Management In Oil Palm

Weed Management in Oil Palm

WEEDS IN OIL PALM • grasses, • broad-leaf weeds (erect, creeping and woody types), • ferns and brackens, • sedges, • epiphytes, • unwanted volunteers and • others

Weeds can affect crops in many ways such as by reducing crop growth and yields through competition for nutrient, sunlight and space

Under open conditions, weeds can immobilize substantial amount of plant nutrients N, P, K, Mg Vegetation

Dry matter production (kg/ha)

Nutrients immobilized (kg/ha) N

P

K

Mg

Mikania1

5986

76

15

120

11

Ischaemum muticum2

11390

73

6

188

9

12240

84

-

-

-

In yielding palms, presence of Mikania micrantha reduced ffb yield by almost 20% over 4.75 years of recording (representing 23.8 tonnes FFB per ha). Cover crops

Yield (t/ha)

%

%

Pueraria + Centrosema

118.03

100

-

Mikania micrantha

94.32

80

20

reduction

Source : adapted from Gray and Hew (1968).

Competitive effect of Ischaemum muticum on 5 years old oil palm Treatments

3 years total ffb yield (t/ha)

%

Blanket spraying

12.2+ 14.0 + 20.5 = 46.7

100

Circle spraying

10.5 + 10.5 + 15.5 = 36.5

78

Source : adapted from Teo et al. (1990).

% reduction

22

GROUND COVERS • protect the ground, especially the topsoil, from soil erosion, runoff and noxious weeds, when the soil is bare after land is cleared for planting when the creeping legume cover crop (LCC) gets shaded out by the mature palm canopy.

• and subsequently, they serve to immobilize and recycle nutrients.

Chiu et. al. (2008) identified 2 stages of ground cover management STAGES

1

2

PLANTINGS & AGE replanting, immaturity plantings up to early mature plantings (3 – 5 years after planting). exceed 5 years and LCC dies from shading or herbicides spraying

GROUND COVERS LCC PLANTING

COVERS of ferns, soft grasses or noxious weeds

legume covers, or natural ground covers are maintained, four types of weeding operations (Corley et al., 1976). 1. clean weeding of palm circle to prevent competition from weeds and to facilitate loose fruit collection, 2. strip weeding to provide access for harvesting and other field operations, 3. selective spot weeding to remove noxious weeds from the legume covers or natural ground covers and, 4. periodic control of legume covers or natural ground covers if growth is too vigorous.

Circle spraying

Strip spraying

Spot spraying

PLANTING OF CREEPING LCC • Sound method of preventive weed management • usually a mixture of Pueraria phaseoloides, Centrosema pubescens, Calopogonium mucunoides, Calopogonium caeruleum and Mucuna cochinchinensis. • recently, planting of a new shade tolerant species, Mucuna bracteata

LCC is an important preventive measure for exclusion of weeds.

BENEFITS OF LCC • many agronomic advantages (reducing soil erosion; addition of organic matter; improving soil aeration and structure; improving soil nutrient status; conserving moisture; fixing atmospheric nitrogen etc.). • in Malaysia and Indonesia showed that palms under LCC cover produce 5.6% 32.1% higher crop than palms under natural cover and improvement mainly contributed from bigger and more bunches

Improvement of oil palm yields planted with LCC FFB yield in t/ha/year

Palm age

References

(years) % increase

LCC

Naturals

19.26

18.24

6

4-6

21.00

15.90

32

6-9

22.80

19.40

18

3 -12

Mathews and Saw, 2007 (Mucuna bracteata )

Chiu and Siow, 2007 (Mucuna bracteata ) Yeow et al., 1982 (Pueraria phaseoloides )

LEGUME COVERS Legume covers reduce soil erosion by breaking the dispersive power of raindrops and also act as an impediment to surface runoff. The faster the establishment of covers the greater is the reduction of surface runoff and soil loss (Ling 1978).

Mean rain run-off at different stages of cover establishment (Ling 1978)

Rainfall in mm Runoff in mm

Cumulative loss for the duration 0-2nd 5th-7th 8th-10th month month month 269.2 311.3 286.7

Bare

56.9

70.8

64.3

Legumes

46.9

18.8

2.4

naturals

3.6

3.5

1.4

Mean soil loss at different stages of cover establishment (Ling 1978)

Rainfall in mm Soil loss in kg/ha

Bare

Cumulative loss for the duration 0-2nd 5th-7th 8th-10th month month month 269.2 311.3 286.7 13,503

30,201

11,237

Legumes

9043

1753

9

naturals

12

5

6

Mucuna bracteata • Goh et al. (2008) reported that in Sabah, planting of Mucuna bracteata decreased runoff losses and erosion in the first 18 months by 30% compared with bare ground.

Mucuna bracteata • higher production of total biomass (about 10.2-14.8 t/ha) and almost 3 times more biomass than conventional LCC (Chiu et al. (2001); Lee et al., (2005); Shaharudin and Jamaluddin (2007)). • Presence of Mb cover is efficient in immobilizing nutrients of the biomass of the old stand during replanting. • Mb cover captures up to 19% N, 37% P and 17% K and 23% Mg from the old stand (Goh et al 2008) .

LCC gave positive yield response • LCC have been shown to reduce weed competition as compared to mixed cover such as grasses, Nephrolepis biserrata and giving positive yield response. • Yeow et al. (1982) reported that the LCC plot planted in inland soil over 10 years able to produce higher yield (additional of 3.2 t/ha or 17% more yield than natural ground cover at 19.6 t/ha).

NATURAL GROUND COVERS • Plants accepted as natural covers are Paspalum conjugatum, Ottochloa nodosa, Axonopus compressus, Adiantum caudatum and Nephrolepis biserrata. • In some cases, erect broadleaved plants like Asystasia gangetica, Ageratum conzoides and Borreria latifolia are accepted as natural cover crops.

NATURAL GROUND COVERS

EFFECT OF BARE GROUND • Top soils contain many essential elements and organic matters. Loss of top soil is serious in bare ground conditions. • It was reported that in Sabah, planting of Mucuna bracteata decreased runoff losses by 30% compared with bare ground and erosion declined from 1484 kg/ha to 80 kg/ha in the first 18 months (Goh et al., 2008).

WEED CONTROL & METHODS • • • • • • •

Manual weeding Mechanical control Cultural control Legal control Animal grazing Biological control Chemical control

Weed control aims at general reduction of weed flora and if possible the eradication of noxious weeds in the cropping areas.

INTEGRATED WEED MANAGEMENT • Definition of IPM given by PANEL OF Experts on Integrated Pest Control, Rome, FAO 1968 • In the broad sense, pests include animal pests, insect pests, pathogens, weeds and others. • Integrated weed management = “using all the available tools to manage weeds in an economical and environmentally safe manner”

INTEGRATED WEED MANAGEMENT • mainly planting of LCC, maintenance of ground covers, EFB mulching, frond placement,

• complimented by manual weeding, mechanical slashing, organized livestock grazing, biological control measures and the spraying of weedicides

WEED CONTROL IN REPLANTING FIELDS • best time for weed control or even eradication of noxious weeds • Clidemia hirta, Hedyotis verticellata, Stenochlaena palustris, Tetracera spp, Momordica charantia, Ischaemum muticum, Imperata cylindrica, Dieffenbachia sp, Schismatoglottis sp, many jungle saplings, vops, etc.

WEED CONTROL IN NURSERY Nursery preparation Soils for filling polybags Mulching Manual weeding Grass cutting Spraying herbicides

WEED CONTROL IN IMMATURE PLANTING Planting LCC / spraying metsulfuron-methyl to control encroachment EFB mulching Not > 45 day rounds Training of workers Use spray shield

WEED CONTROL IN MATURE PLANTING maintain interrow natural ground covers Nephrolepis biserrata, Paspalum conjugatum, Ottochloa nodosa, periodic spraying of noxious weeds use of labour efficient application equipment / techniques

SELECTIVE SPOT SPRAYING

Weeds difficult to control vigorous growth habits, high reproductive potential, herbicide resistance, underground structures Ischaemum muticum, wild bamboo, Pennisetum polystachion, Rottboellia cochinchinensis, Stenochalena palustris, Dicranopteris linearis, Mimosa pigra, Dieffenbachia sp, Caladium sp, Costus sp, wild ginger, wild banana, tuba root (Derris elliptica), wild bitter gourd (Momordica charantia),

Control of Pennisetum polystachyon spray Glyphosate 60 ml per 18 litres water Spray Ally at 3 g per 18 litres water Spray before flowering

control of VOPS spray Glyphosate 450 ml per 18 litres water using spray Glyphosate 250 ml per 10 litres water using F 120 Sprayer

Control of WILD BITTER GOURD – Momordica charantia spray Garlon 60 ml per 18 litres water using CKS Supresate 60 ml + Ally 3 g per 18 litres water  2 rounds required (follow up rounds not > 2 months)

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT • labour shortage, • high turn over of spray workers, • low productivity of unskilled labour, • bioefficacy and choice of herbicides, • spray equipment and calibration, • cheaper generic products,

• herbicide phytotoxicity, • weed resistant to herbicides, • unpredictable wet weather, • OSH and RSPO requirements, and • lack of user friendly technology

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

• labour shortage, • high turn over of spray workers, • low productivity of unskilled labour, Employ local labour force and good wages

• weed control in immature plantings difficult • cause much delay in weeding rounds • severe adverse phytotoxicity • over reliance on contract labour

Herbicide spraying using tractor mounted mechanized sprayer. (Anderson 1976) Plantings

Area (ha)

No of days

55

No of rounds 6

Immature 1st year Immature 2nd and 3rd year Mature

110

4

28

1655

3

168

Total

1820

21

217

SPRAY EQUIPMENT PRODUCTIVITY (Han 1985) equipment CDA

Productivity (ha/man day) 4.8 – 7.3

CP 15

2.4

CKS

1.2 – 1.6

CDA sprayer • A worker operating a CDA sprayer can cover 5 ha per day • in a month of 25 working days, 125 ha can be sprayed. • 1000 ha of mature oil palms, need a team of 8 workers. • The spray gang of 8 workers can spray a 2000 ha mature oil palm estate in every 2 – 3 month rounds giving allowance for holidays, rain interference and other unforeseen circumstances.

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

Non-skilled labour, low productivity of unskilled labour, herbicide phytotoxicity,

training

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

bioefficacy and choice of herbicides

results of field evaluation to determine their cost-effectiveness.

Stem painting of triclopyr products

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

weed resistant to herbicides

Practice Integrated Weed Management

What is herbicide resistance ? • Herbicide resistance, the evolved capacity of a previously herbicide-susceptible weed population to withstand a herbicide and complete its life cycle when the herbicide is used at its normal dose in an agricultural situation, has increased steadily over the past several years (Heap and LeBaron, 2001 - internet).

How herbicide resistance occurs ? • After a long period of repeated and frequent spraying of a single herbicide against the same target weed species, small number of resistant weed emerged. • More and more of such resistant weeds survived and produced seeds which are deposited in the seed bank (the top few cm of soils). • Finally, the herbicide is found to be less effective or completely ineffective at the recommended dosage, due to emergence more resistant weed population.

ELEUSINE INDICA RESISTANT TO GLYPHOSATE (0.54kg/ha)

Expt 1. SUSCEPTIBLE BIOTYPE Complete kill At 28 days after spraying

Expt 2. RESISTANT BIOTYPE Regeneration At 28 days after spraying

HERBICIDES RESISTANCE IN GENERAL • Weed resistance to some herbicides in Malaysia started to appear in the 1990s. > 50 cases have been reported up to now (Chuah and Ismail 2009). • World wide, > 300 cases of herbicide resistant weeds have been reported by Dr. Ian Heap (cited in Chuah and Ismail 2009).

Chuah and Ismail (2009) • reported herbicide resistance (glyphosate, paraquat, metsulfuron and triclopyr) have been detected in oil palm and rubber plantations of Terengganu. glu

Eleusine indica Pq / flu / gly The Chronological Increase of Herbicide-Resistant Weeds in Malaysia

Number of resistant biotypes

60 50 40 30 20 10 0 1985

Chromolaena odorata Gly / tri

Hedyotis verticillata Pq / gly / met

1990

1995

2000 Year

2005

2010

HOW TO PREVENT HERBICIDE RESISTANCE ?

• should integrate weed control tactics (IWM) • avoid spraying herbicides of same mode of action • spray herbicides with different mode of action in sequence • spray mixtures of 2 or more herbicides with different mode of action • timely follow up spraying of weeds at early stage before they flower & produce seeds • integrate non chemical methods of weed control (cutting, mulching)

The world authority in weed resistance management Professor Dr Powles when asked recently in UPM “…..”, he replied that all herbicides must be preserved as tools for the management of herbicide resistant weeds. This is an important point for weed scientists, government regulators and planters to remember.

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

• unpredictable wet • Mulching • Slashing weather, keep weed control at tip top condition spraying during more favourable weather conditions.

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

OSH and RSPO requirements

OSH must be complied at all times. inconvenient and time consuming

ISSUES AND CHALLENGE IN WEED AND COVER CROP MANAGEMENT

• lack of user friendly technology Increase research in biological control

• Biological control • Planting LCC

TERIMA KASIH THANK YOU