CHAPTER 7.

PASTURE PEST MANAGEMENT

CHAPTER 7. PASTURE PEST MANAGEMENT

OVERVIEW:

This chapter discusses the pasture pest management, including specific topics such as insect pests,
diseases, and weeds. Integrated pest management and integrated weed management are also included.
Assessment questions and activities were given to facilitate learnings to students.

LESSON 1. INSECT, DISEASE AND WEED MANAGEMENT

INSECT PESTS AND DISEASES

`Pests and diseases of pastures can severely impact their productivity and the profitability of an enterprise.
The types of pests and diseases that affect pastures vary depending on the type of pasture, the region and the season.

Pests and diseases can have a significant effect on the establishment, yield and longevity of grass and
forage crops. In grassland, new reseeds are most vulnerable to attack and problems are more likely to occur where
grass is the main crop in the area and particularly when grass follows grass.

Infestation of pests, diseases and weeds in fodder /seed crops, further cause enormous losses and aggravates
the availability of green fodder and quality fodder seeds. Hence, there is a need to control infestation of pests,
diseases and weeds using environmental friendly technologies. Few such technologies for insect, disease and weed
control have been standardized for commercial application which when used in conjunction with other pest control
measures prove to be more economic and effective. Such eco-friendly technologies are economically sustainable and
known as Integrated Pest Management (IPM).

INSECT PESTS

Pasture pests include vertebrates, invertebrates, weeds and diseases. Not all insects that live in pastures are
problematic and there are a range of invertebrates that benefit pasture growth by preying on pests. These are known
as 'beneficial insects' and include carabid beetles, predatory mites, native earwigs, brown lacewings, ladybird beetles
and parasitic wasps.

While insecticides can be used to control pest species, they will also usually affect beneficial insects. An
integrated approach to pest control that minimises insecticide use is often the most effective and sustainable
approach.

Frit fly
Frit fly lay their eggs on grass producing three generations a year. The larvae are yellowish-white
and grow up to 5mm long. They feed on the central shoot, killing the plant or leaving patches of stunted and dying
seedlings and moving from seedling to seedling before pupating in the soil and hatching the following spring.

Figure 6. Frit fly

CHAPTER 7. PASTURE PEST MANAGEMENT

Leatherjackets

Lea therjackets are the larvae of craneflies commonly known as ‘daddy-long-legs’. They are up to 50mm
long, a dull olive green, with no obvious head and no legs. Leatherjackets’ skin is tough and rubbery. Adults lay
eggs between July and September in grass and cereals, the eggs hatching after 2-3 weeks. The larvae eat the roots
and stems of grass plants at or below ground level leaving severed leaves and causing stem base damage so plants
yellow then die.
Signs of leatherjacket activity include yellowing and/or bare patches in crops with birds flocking to feed on the
larvae. Damage occurs when leatherjackets are active but most commonly in April/May when they are almost fully
grown. Larvae are found near damaged plants.

Figure 7. Leatherjackets

Sitona weevil

Adult weevils are 3-5mm long, varying from grey to dark grey-brown with three pale stripes between head
and wing covers. The snout is short and broad with a pair of antennae attached to the front. Adults feed in the early
morning and late evening and hide in soil at other times. Larvae are small, white, legless grubs up to 5mm long,
living in the soil near plant roots. Adults are active from spring to autumn. Most eggs are laid in autumn in the soil
around the base of plants and hatch to burrow into the soil. Larvae feed through winter into spring, when they pupate
in the soil and emerge as adults in late spring/early summer. Adults can fly considerable distances, so infestations
can start without a previous history of damage. The adult weevil feeds on the leaves of clover and lucerne cutting
‘U’ shaped notches in edges of leaves. Larvae damage legume root nodules, reducing the plant’s ability to fix
nitrogen. Feeding damage predisposes tissue to attack by crown and root rot fungi.

Figure 7. Sitona weevil

Slugs
CHAPTER 7. PASTURE PEST MANAGEMENT

There are three main types of slug of concern to farmers, of these, the grey field slug is most common. It
breeds at any time of year when conditions are suitable. In a wet summer they breed quickly, each laying up to 300
eggs that can hatch in less than two weeks. Eggs laid in spring produce adults that lay eggs in summer/early autumn.
Slugs graze and shred grass leaves. White clover and grass/clover reseeds are more vulnerable to severe damage
than mature swards where the slugs feed on new leaves in spring reducing yield.

Figure 8. Slugs

Cabbage Stem Flea Beetle

Adult cabbage stem flea beetles are approximately 5mm long, shiny metallic greenish - or bluish- black or
sometimes bronze. They have long antennae and powerful hind legs and move by leaping or flying. The larvae are
white with a brown head and three pairs of legs up to 2.5mm long. Adults over-winter in grass tussocks and hedges
emerging in July and August. Eggs are laid in the soil beneath the crops and larvae emerge after 2-3 weeks. From
late autumn the larvae migrate to the soil to pupate. There is only one generation per year. Damage is caused by both
adults and larvae feeding. Adults eat cotyledons, stems and young leaves leaving characteristic pits and small holes
(shot-holing). The larvae tunnel into the plant tissue. The beetle is now found throughout most of England, Wales
and southern Scotland. There is a risk that flea beetle numbers will increase with climate change.

Figure 9. Cabbage Stem Flea Beetle

DISEASES

Diseases and deficiencies pose a similar risk as pests and should be monitored when checking pastures for
pests. Diseases can generally be classified as leaf diseases such as rusts or root diseases such as wilt or root rot.
CHAPTER 7. PASTURE PEST MANAGEMENT

Management for disease control should be both proactive and reactive.

Proactive control begins prior to pasture establishment and takes into consideration paddock and disease
history as well as pasture species selection for disease resistance.
Reactive disease control involves managing outbreaks and may include strategic grazing and chemical
application. In extreme cases, cultivation and cropping may be required to break a disease cycle.

Where chemicals are used to control pests and diseases, be careful to abide by all export slaughter intervals
(ESI) and withholding periods (WHP) associated with the particular chemical.

Disease management if often limited for forage and pasture crops.

• Resistance
– Check with breeder
– Environment can be important
• Fungicides
– Limits for feeding (read label)
– Better as preventive
• Rotation
• Irrigation/Fertilization

Take-all root rot (Bermudagrass decline)

• Fungal disease caused by Gaeumannomyces graminis var. graminis
• Key diagnostics are yellow symptoms in spring and lobed hyphopodia on stolons
• It can look like or be associated with cold/freeze damage
• Take-all can be found with other diseases and pests (i.e. stem maggot).
• So, it is important to consider these problems in your management strategies
• Best management plan is to avoid stressing the plants.
o Minimal herbicide use is important
o Use acidified fertilizers & do not
o Do not over fertilize
o Mow & regrow to manage this pest
o Fungicides minimal impact
o When it is cold and dry, expect this pathogen to appear. No resistant varieties available.

Bipolaris is a common problem on oats, & can cause significant reductions.

• Often found on debris and dying leaves
• Can move to roots under right conditions.
CHAPTER 7. PASTURE PEST MANAGEMENT

Crown rust on oats

• Favored under cool (50 to 75 F) and wet (dew & rain) conditions.
• Both Bipolaris and Rust can be found at the same time.

WEEDS

Weeds can replace desirable grass species, filling in gaps or voids and reducing yield and overall quality of
pasture and forages. Weeds can produce allelopathic substances that are toxic to crop plants.

Weed competition in pasture systems has not been extensively examined. In pasture, weed control
decisions are based largely on visual thresholds and intuition. Weeds can compete directly with forage grasses or
pasture to reduce their nutritional value and longevity. However, the impacts of weed species, density, and soil and
climatic factors are not well established in pasture systems.

In general, biennial and perennial weeds pose the biggest problems for pasture producers. Both biennials
and perennials produce seed each year, potentially starting new infestations. Pasture-invading weed species should
be assessed for their competitive ability, or their potential to reduce desirable forage species; their invasiveness--
their potential to multiply and increase; their yield, quality, and nutritive value relative to desirable forage species;
and the cost and effectiveness of control measures--cultural, mechanical, and chemical.

General rules about weed competition in forages include:

 Assess weed competitive ability, invasiveness, nutritive value, and potential to control.
 Weeds that emerge with the crop in the spring are generally more destructive.
 Control problem weeds for the first 60 days after seedling establishment.
 Weeds that emerge beyond 60 days after establishment will not influence that year's forage yield.
 Later-emerging weeds may still influence forage quality.
 Winter-annual weed competition in early spring is most damaging to early-season forage yield.
 Broadleaf weeds that are biennial or perennial are generally more competitive than grassy weeds.

WEED QUALITY

Unlike most grain or fiber crops from which weeds are separated at harvest, weeds are often harvested
along with forage crops, potentially reducing quality. In the case of pasture, they remain
 CHAPTER 7. PASTURE PEST MANAGEMENT

in the field where they continue to interfere with desirable forage. Reductions in quality often take the form
of lower protein content, feed digestibility, or even reduced intake by the animals.

Although weeds do have some feed value, the value differs among species. The feed value of many
pasture species has not been extensively studied. However, based on traditional forage quality measures,
crude protein and digestibility, many weeds are nutritious and readily digested during the growing season. Wild
carrot ( Daucus carota), a common pasture weed in some fields, has about 16 percent crude protein in the
vegetative stage. Common yarrow ( Achillea millefolium) has only about 10 percent crude protein during the
flowering stage.

Poisonous Plants

Many plants contain poisonous substances that may be toxic to livestock if consumed. In addition, certain
plants may be problematic because of mechanical irritation when eaten, photosensitization, and disagreeable tastes
or odors in meat, milk, or milk products. If you suspect livestock poisoning, call a veterinarian immediately. If death
occurs, the stomach contents should be examined for consumed herbage. Identify the suspected plants and
remove livestock from the grazing area until all poisonous plants have been removed or destroyed.

WEED MANAGEMENT

Managing weeds in pasture systems begins long before crop establishment. Certain types of weeds are
potentially serious problems for forages, so it is important to eliminate them in advance. If these weeds are not
removed before the seeding is made, they can persist for many years. The cost of controlling weeds before or at
the time of seeding should be considered an investment that will be returned for the life of the forage.

Cultural Management

Cultural practices that aid in weed control include anything that makes the crop more competitive
against weeds.

Preparing the seedbed properly

Provide a seedbed at planting that is free of live weeds. A weed-free seedbed can be achieved using
either tillage or a burndown herbicide. It is important that emerging forage species not have to compete for
limited resources as they try to gain a foothold in the early weeks of establishment. In addition, emerged
vegetation can harbor certain insects or pathogens that could attack young, susceptible forage seedlings.

Planting at the optimum planting date

Date of planting can influence the kinds and numbers of weeds that emerge. Most grass and legume forage
species are relatively slow to establish. For example, if the field has been planted to corn or some other
summer annual crop, then summer annual weeds will likely be the biggest weed threat during establishment. Late
summer may be a better time for establishment in this situation. In spring seedings, plant early before summer
annuals emerge to give the new forage seedlings every advantage. With late summer seedings, plant before
September, the month during which winter annual weeds generally begin to emerge. The weed species present in
a field, along with its potential severity, may help determine the best time for planting.

In established pasture systems, prevention is the most important tool for managing weeds. The
pasture weeds can be controlled by increasing forage competition. In fact, crop growth rate stands as the
single best measure of plant response to weed competition in forages. Maintaining a dense, competitive forage is
a key to preventing weed invasion and interference.
 CHAPTER 7. PASTURE PEST MANAGEMENT

Weeds are opportunistic. Germination and establishment are favored by open areas and by disturbance.
Overseed with desirable forage species when necessary to keep open areas at a minimum. Rotationally graze
to keep traffic effects minimal, and do not overgraze to ensure that forages remain competitive with weeds.
Test soils for nutrients and annually fertilize to keep forage stands healthy and competitive. Control harmful insects
or pathogens when necessary, they weaken forage stands and give weeds the opportunity to establish. Develop
monitoring programs to locate infestations and place priority on controlling small infestations so that they do
not expand.

Preventing weed infestations also means preventing dispersal of seeds or vegetative structures into
uninfested areas. Vehicles, humans, wind, water, birds, and livestock can spread weed seeds. Animals may
disperse seeds by picking them up in their coats or fur, or between the pads of their feet. Cattle have been
shown to readily pick up burs of several weeds when grazing forested range. Clean infested animals regularly,
particularly new animals that may be carrying new weed problems. Ruminants also ingest weed seeds in the
field, between 5 and 15 percent pass safely through sheep, goats, cattle, and deer. Be cautious of feed or hay
infested with noxious weed seed.

Mowing and Hand Removal

Once forages are up and established, systematic mowing helps to control weeds. Mowing is the act of
cutting down (grass, crops) with the hand implement or machine. Repeated mowing reduces weeds' competitive
ability, depletes carbohydrate reserves in their roots, and prevents them from producing seed. Some weeds, mowed
when they are young, are consumed and enjoyed by livestock. Mowing can kill or suppress annual and biennial
weeds. It can also suppress perennials and help restrict their spread. Mow at a height above the grass
seedlings when weeds are 8 to 10 inches in height to reduce shading by weeds.

A single mowing will not satisfactorily control most weeds. However, mowing three or four times
per year over several years can greatly reduce and occasionally eliminate certain weeds. Also, mow along
fences and borders to help prevent the introduction of new weed seeds. Regular mowing helps prevent weeds
from establishing, spreading, and competing with desirable grasses and legumes.

Finally, hand removal may be the easiest and most economical way to control some weeds. When few
plants are present or if you see a potential new weed, dig it, pull it, or remove the seedhead before the seed can
disperse. This technique works particularly well for annuals and biennials. For perennials, it may be difficult to
remove all vegetative structures effectively. Properly dispose of weeds after removal to prevent seed or vegetative
structure dispersal. This may mean burning, burying, or transporting them to local landfills.

Herbicides

Herbicides provide a convenient, economical, and effective way to help manage weeds. They allow fields
to be planted with less tillage, allow earlier planting dates, and provide additional time to perform the other tasks
that farm or personal life require. Herbicides may not be a necessity on some farms, but without the use of
chemical weed control, mechanical and cultural control methods become that much more important.

In pasture systems, a number of herbicides are available for broadleaf weed control in grass forages. Few
are available for mixed grass-legume combinations or for the control of grassy weeds in grass forages. Before
establishment, herbicide choices are limited to those controlling emerged vegetation. Preplant soil residual
herbicides are not common for pasture systems. Most herbicides for pasture systems should be applied
postemergence to the weeds and crop once the forage is well established. In pasture systems, spot spraying may be
the most economical al ternative for scattered infestations of weeds.
 CHAPTER 7. PASTURE PEST MANAGEMENT

Young annual weeds in the seedling stage are most susceptible to control with herbicides. Spray
biennial weeds in the rosette stage prior to bolting. Perennials are most susceptible to control with systemic
herbicides in the bud to bloom stage or in early fall. Most herbicides for broadleaf control in grass pasture
systems should not be applied to seedling forage grass until visible tillers are present. Established forage
grasses and legumes are more herbicide tolerant than seedling forages.

BIOLOGICAL CONTROL

Biological control is the deliberate introduction or manipulation of a pest's natural enemies, with the
goal of suppressing the pest population. It has been used to manage insects, vertebrates (mice and rats),
pathogens, and weeds. Biological control is not intended to eradicate the target weed, but rather to exert enough
pressure on the pest to reduce its dominance to a more acceptable level. Biological control can be cost effective,
environmentally safe, self-perpetuating, and well suited to an integrated weed management program. Its limitations
are that it is a long-term undertaking, its effects are neither immediate nor always adequate, only certain weeds
are potential candidates, and the rate of failure for past biological control efforts has been fairly high.

Biological control tools for weeds have included insects, mites, nematodes, pathogens, and grazing animals
(e.g., sheep and goats). Historically, insects and mites have been the most important biological control tools for
weeds

INTEGRATED WEED MANAGEMENT (IWM)

It is an important component of a total IPM program. Weeds not only decrease fodder /seed yield by
competing with crop for water, light and nutrients but also make fodder unpalatable. Weeds also provide shelter to
many insect-pests and cause diseases leading to economic losses. IWM combines a variety of approaches to suppress
weeds and reduces dependence on herbicides for weed control.

a. Deep tillage during summer.

b. Proper field preparation.
c. Sowing of certified/truthfully labelled fodder seed for fodder production.
d. Application of well decomposed farm yard manure.
e. Keeping irrigation channels and field boundaries free from weeds.
f. Using crop residues for mulching.
g. Changing crop sequences.

Precautions to be taken while handling, applying and storing pesticides

i. Keep the container of pesticides in a locked place, away from children, animals and food.
ii. Use pesticides as per instructions mentioned on the container.
iii. Buy pesticides from reputed source. Do not buy expired pesticides.
iv. Wear hand gloves, face mask and full clothes while applying pesticides. v. Spray pesticides in cool and
calm weather.
v. Do not wash spray equipment’s in ponds and rivers.
vi. Empty containers and packets of insecticides should be disposed properly.

INTEGRATED PEST MANAGEMENT

Integrated pest management (IPM) involves using a combination of biological, cultural and chemical
methods to control pests. As beneficial insects are a key component of IPM, the use of insecticides is minimised, but
not excluded altogether.

The first step in IPM is to identify and understand the lifecycle of the pests and beneficial insects present.
A plan can then be put in place to manage the populations of both beneficial and pest insects.
CHAPTER 7. PASTURE PEST MANAGEMENT

Careful and ongoing monitoring is then required to ensure that a favourable population is maintained. Monitoring
also allows corrective actions, such as slashing, pasture rotation or spraying, to be undertaken when pest numbers
impact pasture production.

Infestation of pests, diseases and weeds in fodder /seed crops, further cause enormous losses and
aggravates the availability of green fodder and quality fodder seeds. Hence, there is a need to control infestation of
pests, diseases and weeds using environmental friendly technologies. Few such technologies for insect, disease and
weed control have been standardized for commercial application which when used in conjunction with other pest
control measures prove to be more economic and effective. Such eco-friendly technologies are economically
sustainable and known as Integrated Pest Management (IPM).

Integrated Pest Management It is an ecologically based strategy that focuses on long-term solution of pests
through a combination of techniques such as biological control, habitat manipulation, modification of agronomic
practices and use of resistant varieties. Embracing a single tactic to control a specific organism does not constitute
IPM, even if the tactic is an essential element of the IPM system. Pesticides may be used to remove/prevent the
target organism only after assessing that they are needed to prevent economic damage. Pest control tactics, including
pesticides, are carefully selected and applied to minimize risks to the human health, beneficial & non-target
organisms and environment.

Through IPM approach farmers need to be advised to use the following practices:

a. Cultural pest control

• Use treated seed of improved varieties, resistant to disease/pest.
• Timely planting/sowing of crops and follow proper crop rotations.
• Fallowing of field and destruction/burning of old crop debris.
• Removal of weeds from field boundaries and deep ploughing during summer.

b. Physical and mechanical control

• Manual destroying of insect pests eggs, larvae and pupa etc.
• Pheromone trap is a type of insect trap that uses pheromones to lure insects. Sex pheromones and
Aggregating pheromones are the most common types used.
• Insect light trap is also one of the very effective tools of insect pest management in organic
agriculture. The ordinary light trap consists of an electric bulb emitting yellow light as attractant
and a funnel to direct lured insects into a container containing water.

c. Biological control
• Rearing biological control agents for their field use and conservation of naturally occurring bio- agents
such as Trichogramma spp., Lady bird beetle and Chrysopa.
• Installation of bird perches @ 15 per hectare for attracting predatory birds.

d. Organic pesticides
• Promotion of bio-pesticides such as Neem seed kernel extract @ 5 per cent as alternative to
chemical pesticides.
• Spray of nuclear polyhedrosis virus (NPV) suspension @ 2.5 ml/10 litre of water are
recommended for the control of foliage eating spodoptera and heliothis spp. larvae.
• For the effective management of Helicoverpa armigera larvae spraying of Bacillus thuringiensis @
1 kg/ha at flowering stage is recommended.
• Soil application @ 1.25 kg/ha or seed treatment with 5g/kg of seed of different fodder crops
before sowing by bio-fungicide like Trichoderma viride, Verticillium spp., Aspergillus spp., etc.
that attack and suppress the growth of harmful soil borne plant pathogens causing root decay.
Anthracnose fungal disease in Sorghum

e. Chemical control:
When above mentioned efforts fail to control pests, recommended chemicals may be used at proper
stage.
CHAPTER 7. PASTURE PEST MANAGEMENT

ACTIVITY 6

PASTURE PEST MANAGEMENT

I.
Instruction: Fill out the table with the data required.
PEST/
CAUSAL ORGANISM/ AFFECTED AFFECTED
PREVENTION
(Insect pest, diseases, FORAGE FORAGE
weeds, etc.) PART
1.

2.

3.

4.

5.

II.
1. Cite the factors to be considered in establishing pasture in connection to pasture pest
management.
2. What is the significance of considering those factors toward successful pasture production?

SUMMARY

Key points about weed forage quality and poisonous plants:

 Some weeds have excellent nutritive quality.

 Weeds in the vegetative stage of development usually are more desirable than mature weeds.
 Regardless of weed quality, livestock may avoid grazing certain plants because of taste, smell, or
toxicity.
 Some plants contain poisonous substances that may be toxic to livestock if consumed. Properly
identify potential problem weeds and consult with a veterinarian if necessary.

Key points about cultural weed management:

 Consider seedbed preparation, planting date, fertilization, planting population, and high- quality
crop seed, and select adapted species and varieties.
 In established pasture systems, prevention is the most important tool for managing weeds.
 Overseed with desirable forage species when necessary to keep open areas to a mini mum.
 Rotationally graze to keep traffic effects minimal and do not overgraze.
 Test soils for nutrients and annually fertilize to keep forage stands healthy and competitive.
CHAPTER 7. PASTURE PEST MANAGEMENT

 Prevent dispersal of seeds or vegetative structures into uninfested areas.

Key points about mowing and hand removal:

 Repeated mowing reduces competitive ability, depletes root carbohydrates, and prevents seed
production.
 Mow at a height above the grass seedlings when weeds are 8 to 10 inches tall to reduce shading.
 If you see a new weed, dig it, pull it, or remove the seedhead before seeds can disperse.

ASSESSMENT:

I. MULTIPLE CHOICE

1. Which is true about pasture pest?

a. All insect and diseases in pastures are problematic thus need to be eradicated immediately.
b. Pasture pest includes vertebrates, invertebrates and diseases only. Weeds and insects are considered
to be beneficial.
c. Not all insects in pasture are problematic and some benefit the pasture growth by preying on pests.
d. All are correct.
2. This involves managing outbreaks and may include strategic grazing and chemical application.
a. Reactive disease control
b. Proactive control
c. Active control
d. Passive control
3. This begins prior to pasture establishment and takes into consideration paddock and disease history as
well as pasture species selection for disease resistance.
a. Reactive disease control
b. Proactive control
c. Active control
d. Passive control
a. All of the above

4. Cultural practices aid in weed control include anything that makes the crop more competitive against
weeds. Which of the following is true about cultural management?

a. Providing proper seedbed at planting that is free of live weeds is important

b. Date of planting can influence the kinds and numbers of weeds that emerge.
c. The pasture weeds can be controlled by increasing forage competition.
d. All of the above.

5. All statement about weeds in the pasture is true, except one:

a. Weeds can replace desirable grass species.
b. Weeds can produce allelopathic substances that can be useful to crop plants.
c. Weeds can compete directly with forage grasses or pasture to reduce their nutritional value and
longevity.
d. Weeds do have some feed value, the value differs among species
6. Plants containing poisonous substance may be toxic to livestock if consumed and can be a problem
because of :
b. mechanical irritation when eaten
c. photosensitization
d. disagreeable tastes or odors in meat, milk, or milk products
7. It is the act of cutting down (grass, crops) with the hand implement or machine.
CHAPTER 7. PASTURE PEST MANAGEMENT

a. Cutting of weeds
b. Mowing
c. Moving
d. Hand removal
8. It is consider to be the easiest and most economical way to control some weeds.
a. Prevention
b. Hand removal
c. Herbicides
d. All can be used.

9. It is the most important tool for managing pest in established pasture system.
a. Eradication
b. Suppression
c. Prevention
d. Both a and b
10. Preventing weed infestation also means
a. preventing dispersal of seeds or vegetative structures only into infested areas
b. suppressing weeds at acceptable level because some are beneficial
c. preventing the spread of seeds or vegetative structures into uninfested and infested areas
d. all of the above

II. TRUE OR FALSE

11. Single mowing will satisfactorily control most weeds.

12. Insecticides can be used to control pest species but also usually affect beneficial insects.
13. In general, biennial and perennial weeds pose the biggest problems for pasture producers.
14. Hand removal is an effective control that works particularly well for annuals, biennial, and
perennials.
15. Properly disposing of weed or vegetative structure after removal is part of weed prevention
16. Most herbicides for pasture systems should be applied preplant to the weeds.
17. The role of biological control is to supress the pest populataaion.
18. Biological control uses solely insects (predators, natural enemies) to control pasture pests.
19. Weeds make fodder unpalatable.
20. Weeds benefits insects and favour also diseases that leads to economic loss of the pasture.

III. ESSAY.

21-30. In connection to pasture pest, write the concept, including the pros and cons of the following:

a. Cultural control
b. Biological control
c. IPM
d. IWM

REFERENCES

https://extension.psu.edu/weed-management-in-pasture-systems

Oregon State University. Forage Information System

Barnes R.F., Nelson C.J., Collins M., and Moore K.J. 2003. Forages. Volume I. An Introduction
CHAPTER 7. PASTURE PEST MANAGEMENT

to Grassland Agriculture. 6th Ed.

Shewmaker G.E and Bohle, M.G. 2010. Pasture and Grazing Management. A Pacific Northwest
Extension Publication.
Batello,C.et.al. Plant Genetic Resources of Forage Crops, Pasture and Rangelands.