Cropping system, Grassland management, Agro-forestry and allelopathy

1. Presented by: Ravi Siwach
Ph.D. Agronomy
CCS Haryana Agricultural University, Hisar
Agron-601

2. Cropping systems
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3. Cropping systems:- It is defined as the order in which the crops are grown or
cultivated on a piece of land over fixed period.
Cropping Pattern:- The yearly sequence and spatial arrangement of crops on a same
piece of land over a same period of time
Classification/Types of cropping systems:- 1) Monoculture 2) Multiple cropping 3)
Following or Fallow in rotation
Multiple cropping is divided into :
1) Parallel Multiple cropping:
1) Mixed cropping 2) Intercropping 3) Relay cropping 4) Alley cropping
5) Multistroyed cropping
2) Sequential Multiple cropping:
i) Sequential cropping
a) Double cropping b) Triple cropping c) Quadruple cropping
ii) Ratoon cropping/Ratooing
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4. A. Cropping systems for dryland and irrigated areas:-
I) Monoculture/Monocropping:- The cropping system in which
only one major crop is grown on the same land year after year.
Or Repetitive growing of only one crop on same piece of land
year after year. e.g Bajra-Bajra
Advantages of monoculture/monocropping:- 1) Convenience in
sowing with the help of machinery under mechanized farming 2)
It is convenient for harvesting with the help of machinery
Disadvantages:- 1) Sometimes fertility and productivity of the soil are
lowered if suitable soil management practices are not followed.
2) Soil structure may be deteriorated. 3) Increase infestation of
pests, diseases and weeds.
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5. 2. Intensive Cropping systems:
I) Multiple cropping:- The cropping system in which two or more crops are grown either
in succession or sequence or association for entire or part period of their life cycles on
the same field in a year is called multiple cropping. E.g. Sorghum-Wheat-Green Gram,
Maize-Wheat-Green gram, Rice-Wheat-Black gram-Linseed
a) Parallel multiple cropping:- When two or more crops are grown in association for part
or entire period of their life cycle is known as parallel multiple cropping. It includes
following cropping systems.
i) Mixed cropping:- Growing two or more crops simultaneously with no distinct row
arrangement is known as mixed cropping. E.g. Maize + Green gram + Pigeon pea,
Sorghum + Groundnut + Pigeon pea
• Mixed cropping is common practice in rainfed or dry farming areas.
• Generally, legumes crops like red gram, black gram, green gram, cowpea etc. or oilseed
crops like groundnut, mustard etc. are mixed with cereal crops like jowar or bajra.
• Sowing is done by drilling the mixture of seed with the help of seed drill or moghan can
be attached behind the seed drill for sowing of mixed crop.
• Usually, cereals are grown as main crop and pulses or oilseeds as minor or mixed crop
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6. Advantages of mixed cropping:- 1) Risk of failure of crop is less 2) Fullfills the daily
requirements of food grains, oilseeds, pulses etc. 3) Improve fertility of the soil if
legumes are taken as minor crop 4) Better distribution of labour through out the
crop period 5) Increase gross monetory returns 6) Well balanced cattle feed is
obtained 7) Safeguards against pests and diseases 8) Full utilization of space and
available plant nutrients
Disadvantages:- 1) Some times control of pests, diseases and weeds become difficult
2) Some times affects the yield of main crop 3) Harvesting with the help of
machinery is not possible
ii) Intercropping:- It is cropping system in which intercrop is grown in between rows
of the major crop, without affecting the optimum plant population as well as
yield of the major crop (base crop) or growing two or more crops simultaneously
on the same piece of land with distinct row arrangement is called as
intercropping.
E.g. Maize + Pigeon pea (2:1), Sorghum + Pigeon pea (2:1) ,Cotton + Green gram (2:1)
Pigeon pea + Ground nut + Lentil (2:1:1)
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7. Characteristics of good intercrop/minor crop/subsidiary mixed crop:- 1) It
should not affect the growth and yield of base crop or main crop. 2) It
should mature earlier or latter than the base crop or main crop. 3) A far as
possible it should be a legume crop for maintaining fertility and
productivity of the soil. 4) It should have different growth habits and
nutrient requirements in order to have minimum competition. 5) It should
have different rooting depths. 6) It should differ in canopy development
and sunlight requirement.
Advantages of intercropping system: 1) It should helps to Improves the soil
fertility and soil productivity. 2) Maintaining the higher crop yield. 3)
Better utilization of available resources 4) It should resist the soil erosion.
5) Reduces the incidence of insect pest, disease and weeds. 6) Improves the
soil structure and water holding capacity of soil.
Disadvantages: 1) Harvesting with the help of machinery is difficult. 2)
Intercultural operations are not possible. 3) Competition among the
resources is more. 4) Harvesting makes a time consuming/difficult. 5) Weed
control is not possible. 6) Water requirement is more
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8. a) Parallel Cropping:- Cultivation of such crops which have different natural habit and zero
competition is called as parallel cropping. e.g. black gram/green gram + Maize.
b) Companion cropping:- System in which production of both intercrops is equal to that of
its solid planting is called as companion cropping. e.g. Mustard/Potato/Onion +
Sugarcane.
c) Mixed Intercropping:- Growing of two or more crops with no distinct row arrangement
is called as mixed intercropping. There are four types of mixed intercropping systems:-
1. Row intercropping:- Growing of two or more crops simultaneously, where one or more
crops are planted in rows is called as row intercropping.
2. Patch cropping:- Where component crops are planted in patches is called as patch
cropping.
3. Strip intercropping:- Growing of two or more crops simultaneously in strips wide enough
to permit independent cultivation but narrow enough to interact the crop agronomically
is called as strip intercropping.
4. Relay intercropping:- Growing of two or more crops simultaneously during the part of
life cycle of each is called as relay intercropping. Second crop is planted after the first
crop has reached its reproductive stage of growth but before it is ready for harvest.
Suceeding crop is planted before harvesting of preceeding crop. 8
Types of Intercropping

9. iii) Relay cropping:- It is the cropping system in which succeeding crop (next crop)
is or sown or planted when the first crop (preceding crop) has reached its
physiological maturity stage or before it is ready to harvest is called as relay
cropping. e.g. Rice-Linseed/lentil/black gram/chickpea.
Advantages of relay cropping:
1) Better utilization of residual moisture and fertilizers.
2) Reduces the cost of cultivation practices.
3) Also reduces the cost of fertilizers and irrigation.
4) Labour requirement is less.
5) Incidence of pest, diseases and weeds is less due to early sowing operation.
Disadvantages:-
1) Risk of crop failure is more.
2) Harvesting by means machinery is difficult.
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10. iv) Alley cropping:- The system of growing jowar, maize, bajra or any other arable crop in the
alleys (passage between two rows) of leguminous shrubs like subabul (Leucaena
leucacephala) is called as alley cropping.
• Growing of maize, jowar, bajra, cowpea in between rows of subabul planted at 5-10 m
spacing, this system is useful for conservation of moisture and maintaining fertility of soil in
dry farming areas.
• The loppings of the subabul are used as green fodder for animals or spread in between the
crop rows as mulch for conservation of soil moisture and after delaying it adds organic
matter to the soil.
Advantages of alley cropping:
1) Better utilization of natural resources. 2) Reduces the cost of cultivation.
3) Improves the soil fertility and productivity. 4) Provides fodder for animals and food for
human.
Disadvantages:
1) Competition among the natural resources i.e moisture, nutrients, light and space.
2) Incidence of pest, diseases and weeds is more.
3) Chances of crop failure is more.
4) Less yield is obtained.
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11. Multistoreyed cropping:- In this system the crops of different height and vertical layers of
leaf canopies, sunlight requirements and root system are grown together on the same field
is called as multistoreyed cropping.
• Generally, the shorter crops favouring shade and humidity are grown in passage between
the rows of taller crops, which are tolerant to strong sunlight.
• e.g. Growing of pineapple, sweet potato, black pepper, tapioca, turmeric, ginger etc. in
coconut or arecanut.
Advantages of Multistoreyed cropping:
1) Better utilization of moisture and nutrients in different soil layers.
2) Better utilization of sunlight and space.
3) Provides a balanced food for humans.
4) Enrichment of organic matter or plant residues in soil.
5) Improve the water holding capacity of soil
Disadvantages:
1) Competition among the natural resources.
2) More area is required.
3) Lack of labour availability
4) Incidence of pest, disease and weeds is more.
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12. Grassland
management
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13. 13
• Grasslands are directly grazed by the livestock and provide nourishment to
them or they can also be harvested and stored for feeding during the lean
periods as hay.
• The managed grasslands with high yielding species and proper fertility are
also known as 'pasture'.
• The composition and the quality of grasslands vary along different soil and
climatic variables. They are described as grass cover with their specific
productivity and quality.
• When grasslands are managed along with intercropping of trees they are
known as ‘silvipastures’. Trees are mostly fodder trees which are lopped for
fodder.
• Pastures or grass lands are those covered with grasses and other edible plants
of the locality that can be used for livestock grazing.
• Grassland - a land with more than 80% occupied by grasses.
• Rangeland - a piece of vegetation (with grasses, legumes, shrubs and few trees)
where in grazing occurs or can occur.
• Pasture - a piece of land in which grasses are grown/cultivated and managed
for feeding.

14. Different types of available lands used for grazing in India
a)Forest areas - grazing inside forests, especially by goats and sheep is being
severely restricted now by the authorities of the forestry departments, game
parks, reserves etc.;
b) Common village lands - the open lands that are not private property but are
owned by the village community or Panchayat as a whole and are accessible to
all. Even this area is now subjected to encroachments and diverted for other
purposes.
c) Embankments - of rivers, canals and ponds where herbage grows due to the
available sub-soil moisture;
d) Bunds of crop fields - These are the bunds that separate crop fields. Since very
little walking on them is involved, grasses grow on them. The danger while
grazing on them involves animals straying onto the crop proper;
e) Hill-slopes, especially in humid and sub-humid areas; and
f) Fallow lands - permanent fallows and current fallows (open lands between
crops). About 50% of the total area available as wastelands, is endowed with
extremely poor soil, water and nutrient situation where cropping is just not
possible. Any effort to allocate these lands for crops would only add to the
uncertainty of agricultural production. Such lands have to be used with a low
level of intensity. 14

15. Principles of grassland management
The grasslands normally considered to be the cheapest source of
animal feed are in a degraded state because of overgrazing and misuse
over the years. Therefore, the improvement and conservation of
natural grasslands and pastures deserve special and careful attention
and priority in our drive for increasing forage production. Grassland
management for its improvement can be achieved by adopting the
following approaches:
• Ecological succession : The ecological succession is a natural process
of vegetation development under protection which takes longer time
• Assisted ecological : In case of assisted ecological, the process of
succession is assisted by improvement in soil and water conservation,
soil fertility and seeding with better productive species. This method
speeds up the development process.
• Intensive management: In intensive management, all the package of
practices for development of a productive pasture are followed and in a
short time, the productive pasture is ready for utilization.
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16. The sequence of activities for assuring a
managed grassland system:
• Protection from overgrazing,
• Soil and water conservation,
• Bush cleaning,
• Re-seeding,
• Fertilizer application,
• Legume introduction and cutting, and
• Grazing management.
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17. i) Protection from grazing: Protection through fencing brings remarkable recovery of
vegetation. Grazing lands can be protected through barbed/woven/chicken wire chain
links supported by angle iron/cement/stone/wooden poles or through fencing by
unpalatable bushes.
ii) Soil and Water Conservation: Mostly, degraded grasslands are situated on sloppy, rocky
and gravelly soils on undulated surfaces where precipitation is lost faster due to runoff
leaving the soil dry. Proper land treatment under the principles of watershed with
contour bunds, staggered contour trenches, gabion structures, earthen check dams and
masionary check dams facilitates in-situ water conservation.
iii) Bush Cleaning : Heavy infestation of unpalatable bushes in degraded grazing lands not
only adversely affects the availability of open space for growing grasses, but also forage
production. The standard practice of bush cleaning includes either manual or
mechanical felling and removal of stumps, or application of selective weedicides on the
cut stumps to kill them.
iv) Reseeding: For the quick improvement of productivity of deteriorated
grasslands/rangelands, it is essential to replace low yielding annual grasses by re-seeding
with high yielding perennial grasses and legumes which are adaptable to the prevailing
condition of the region. Species choice depends upon the condition of site, soil type and
intended use.
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18. v) Fertilizer Application: Both forage production and quality of grasses in terms of per cent
crude protein can be improved considerably by application of nitrogen. Research studies
have revealed that application of 40-60 kg N/hectare and 20-30 kg P2O5/hectare have
increased pasture production by 50 to 100% in majority of grasses besides increasing
crude protein content considerably.
vi) Legume introduction and cutting: The concept of growing legumes and non-legumes as
pasture components has been an important feature of agriculture from early days.
Grass-legume mixtures are always desirable because of their complementary functions
in providing nutritive, succulent, palatable forage for the grazing animals. The mixtures
also improves the physical conditions of the soil, check soil erosion, resist the
encroachment of weeds and withstand the vagaries of weather better than pure stands.
They also help to check the spread of certain diseases and insect pests.
vii) Grazing Management: The greatest single factor, which causes deterioration of
grasslands, is overgrazing. During the course of grazing, certain grasses are preferred
while others are avoided. On account of this, selective grazing, desirable species tend to
get depleted in grasslands much faster than undesirable species. In most perennial
grasses, utilizing the reserve food material that is stored in the underground parts
produces new shoots. Due to overgrazing, the reserve food material is lost faster and
perennial grasses are unable to re-generate due to continuous drain on food reserve.
Therefore, certain period of rest is essential for the perennial grasses to recoup and
rejuvenate.
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19. Agro-forestry
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20. Introduction
• Agroforestry is a collective name for land-use systems
involving trees combined with crops and/or animals on the
same unit of land. It combines
1) Production of multiple outputs with protection of the
resource base;
2) Places emphasis on the use of multiple indigenous trees
and shrubs;
3) Particularly suitable for low-input conditions and fragile
environments;
4) It involves the interplay of socio-cultural values more
than in most other land-use systems; and
5) It is structurally and functionally more complex than
monoculture.
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21. Definitions
1) Agroforestry is any sustainable land-use system that
maintains or increases total yields by combining food crops
(annuals) with tree crops (perennials) and/or livestock on the
same unit of land, either alternately or at the same time, using
management practices that suit the social and cultural
characteristics of the local people and the economic and eco-
logical conditions of the area.
2) Agroforestry is a collective name for a land-use system and
technology whereby woody perennials are deliberately used
on the same land management unit as agricultural crops
and/or animals in some form of spatial arrangement or
temporal sequence. In an agroforestry system there are both
ecological and economical interactions between the various
components.
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22. Different terminologies
1) Farm Forestry: Farm forestry is the name given to programmes which
promote commercial tree growing by farmers on their own land. Farm forestry
was defined as the practice of forestry in all its aspects in and the around the
farms or village lands integrated with other farm operations.
2) Extension Forestry: It is the practice of forestry in areas devoid of tree
growth and other vegetation situated in places away from the conventional forest
areas with the object of increasing the area under tree growth.
It includes the following.
a) Mixed forestry
It is the practice of forestry for raising fodder grass with scattered fodder trees,
fruit trees and fuel wood trees on suitable wastelands, panchayat lands and
village commons
b) Shelterbelts
Shelterbelt is defined as a belt of trees and or shrubs maintained for the purpose
of shelter from wind, sun, snow drift, etc.
c) Linear Strip plantations
These are the plantations of fast growing species on linear strips of land.
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23. TYPES OF AGROFORESTRY SYSTEMS
1. STRUCTURAL BASIS :
A. NATURE OF COMPONENTS:
I) AGRISILVICULTURAL SYSTEMS: In this system, agricultural crops are intercropped
with tree crops in the interspace between the trees. Under this system agricultural crops
can be grown upto two years under protective irrigated condition and under rainfed
farming upto four years. The crops can be grown profitably upto the above said period
beyond which it is uneconomical to grow grain crops. However fodder crops, shade loving
crops and shallow rooted crops can be grown economically. Wider spacing is adopted
without sacrificing tree population for easy cultural operation and to get more sunlight to
the intercrop. Performance of the tree crops is better in this system when compared to
monoculture.
II) SILVOPASTORAL SYSTEMS: The production of woody plants combined with pasture is
referred to Silvipasture system. The trees and shrubs may be used primarily to produce
fodder for livestock or they may be grown for timber, fuel wood, fruit or to improve the
soil. This system is classified in to three categories
a) Protein bank
b) Livefence of fodder trees and hedges
c) Trees and shrubs on pasture
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24. a) Protein bank:
In this Silvipastoral system, various multipurpose trees (protein rich trees) are
planted in or around farmlands and range lands for cut and carry fodder
production to meet the feed requirement of livestock during the fodder deficit
period in winter.
Example: Acacia nilotica, Albizia lebbeck, Azadirachta indica, Leucaena
leucocephala, Gliricidia sepium, Sesbania grandiflora
b) Livefence of fodder trees and hedges:
In this system, various fodder trees and hedges are planted as live fence to
protect the property from stray animals or other biotic influences.
Example: Gliricidia sepium, Sesbania grandiflora, Erythrina sp, Acacia sp.
c) Trees and shrubs on pasture:
In this system, various tree and shrub species are scattered irregularly or
arranged according to some systemic pattern to supplement forage production.
Example: Acacia nilotica, Acacia leucophloea ,Tamarindus indica, Azadirachta
indica.
III) AGROSILVOPASTORAL SYSTEMS
• The production of woody perennials combined with annuals and pastures is
referred Agrisilvopastural system.
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25. B. ARRANGEMENT OF COMPONENTS
I) Spatial Arrangement: Spatial arrangement of plants in an
agroforestry mixture may result in dense mixed stands ( as in home
gardens) or in sparse mixed stands ( as in most systems of trees in
pastures).
II) Temporal Arrangement: Temporal arrangements of plants in
Agroforestry may also take various forms. An extreme example is the
conventional shifting cultivation cycles involving 2-4 years of cropping
and more than 15 years of fallow cycle, when a selected woody species or
mixtures of species may be planted. Similarly, some silvipastoral systems
may involve grass leys in rotation with some species of grass remaining
on the land for several years. These temporal arrangement of
components in agroforestry are termed coincident, concomitant,
overlapping, separate and interpolated.
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26. 2. FUNCTIONAL BASIS
All agroforestry systems have two functions.
A) Productive functions
B) Protective functions
The Productive functions are: The Protective functions are:
I) Food I) Wind break
II) Fodder II) Shelterbelt
III) Fuel wood III) Soil conservation
IV) Cloths IV) Soil improvement
V) Shelter
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27. BENEFITS OF AGROFORESTRY SYSTEM
A) Environmental benefits
i) Reduction of pressure on natural forests.
ii) More efficient recycling of nutrients by deep rooted trees on the site
iii) Better protection of ecological systems
iv) Reduction of surface run-off, nutrient leaching and soil erosion through impeding effect of tree
roots and stems on these processes
v) Improvement of microclimate, such as lowering of soil surface temperature and reduction of
evaporation of soil moisture through a combination of mulching and shading
vi) Increment in soil nutrients through addition and decomposition of litterfall.
vii) Improvement of soil structure through the addition of organic matter from decomposed litter.
B) Economic benefits
i) Increment in an outputs of food, fuel wood , fodder, fertiliser and timber;
ii) Reduction in incidence of total crop failure, which is common to single cropping or monoculture
systems
iii) Increase in levels of farm income due to improved and sustained productivity
C) Social benefits
i) Improvement in rural living standards from sustained employment and higher income
ii) Improvement in nutrition and health due to increased quality and diversity of food outputs
iii) Stabilization and improvement of communities through elimination of the need to shift sites of
farm activities.
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28. Allelopathy
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29. Allelopathy
• It was Molisch, H. who first rigorously outlined the concept and presented us
with the term Allelopathy in 1937.
• The word allelopathy is derived from two separate words, viz., allelon which
means "of each other", and pathos which means "to suffer".
• Thus, Allelopathy refers to the chemical inhibition of one species by another.
The "inhibitory" chemical is released into the environment where it affects the
development and growth of neighboring plants.
• Allelopathy is an ecological phenomenon of plant-plant interference associated
with release of organic chemicals (allelochemicals) in the environment.
• Allelochemicals are directly released by the donor plants in their immediate
environment as volatiles in the air or root exudates in soil or they can be the
microbial degradation products of plant residues
• Allelopathic chemicals can be present in any part of the plant (leaf, flower,
root, fruit, or stem).
• The chemicals may interfere with survival and growth of neighboring or
succeeding plants.
• Black walnut, eucalyptus, sunflower, sorghum, sesame and alfalfa are
common examples
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30. How allelochemicals introduced
into plant??
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31. Factors affecting production of allelochemicals
Varieties: There can be a great deal of difference in the
strength of allelopathic effects between different crop
varieties.
Specificity: A crop which is strongly allelopathic against one
weed may show little or no effect against another.
Environmental factors: Several factors impact on the
strength of the allelopathic effect, especially soil fertility.
Low fertility increases the production of allelochemicals.
After incorporation the alleopathic effect declines fastest in
warm wet conditions and slowest in cold wet conditions.
Autotoxicity: Allelopathic chemicals may suppress same sp.
Lucerne is particularly known for this kind of autotoxicity.
The toxic effect of wheat straw on following wheat crops is
also well known.
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32. Types of allelopathy
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33. Grummer’s classification
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34. There are two types of allelopathy :
1) True type: The release into the environment
of compounds that are toxic in the form in
which they are produced.
2) Functional type: The release into the
environment of a substance that is toxic as
the result of transformation by micro-
organisms
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35. 2/11/2023 35

36. Allelopathic effects of crops on weeds
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37. Sources of allelochemicals
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38. Liberation of allelochemicals
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39. Volatalization:
• Arid and semi arid environment
• Mostly terpinoid group.
• Released from special glands on stems or leaves
• Susceptible plants absorbs through cuticle directly from air or
adsorbed on dry soil and taken up.
Leaching:
• Through aqueous solutions (rain, dew)
• Mature leaf are more susceptible
Exudation:
• Metabolites exuded from roots to surrounding atmosphere
• Potential source of allelopathic effect ture leaves are more
susceptible
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40. Mechanisms of action
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41. Inhibition of plant species through allelopathy
• Rye, some varieties of barely, oats as well as buckwheat are effective
inhibiting the growth habit of a large number of weed species.
• Root exudates of wheat and oats contained phenolic acid which has
more detrimental effects on wild mustard.
• Sunflower crop inhibit the growth of certain weeds.
• Cucumber which strongly inhibit the growth of wild mustard
• Root inhibition of rye grass weed is influenced by wheat seed density
• The leaf litter and root exudates of some Eucalyptus species are
allelopathic for certain soil microbes and plant species.
• The tree of heaven, Ailanthus altissima, produces allelochemicals in its
roots that inhibit the growth of many plants.
• Continuous cropping of legume crop alfa-alfa has been created to auto
toxicity in low land weed.
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42. Commercial herbicides based on natural products
1. Organophosphorous compounds
2. Triketones
3. Cinmethylin
4. Selected allelochemicals
• Benzoquinones
• Coumarins and flavonoids
• Terpenoids
• Strigolactones
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43. SYMBOL OF TRUST