The document discusses various environmental factors that influence plant growth, including both biotic and abiotic factors. It describes abiotic factors like water, sunlight, temperature, soil composition and topography that affect plant survival and development. It also discusses important biotic factors such as producers, consumers, decomposers and their interactions through parasitism, mutualism, herbivory and allelopathy. Specific environmental conditions required for plant germination, growth and reproduction are also outlined.

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3.  Environment is everything that is around us. It can be
consisted of living or non-living things
 It includes physical, chemical and other natural forces
Living things live in their environment
 In the environment there are different interactions
between animals, plants, Insects soil, water, and other
living and non-living things

4. Factor is a substance that takes part in a
biochemical reaction or a biological process
A component in the environment that influence other
components of the environment
Environmental factor or ecological factor is any
factor, abiotic or biotic, that influences living organisms

5.  Abiotic factors are non-living chemical and physical
parts of the environment that affect living organisms
and the functioning of ecosystems.
 Abiotic components include physical conditions and
non-living resources that affect living organisms in
terms of growth, maintenance, and reproduction.

7.  Most plant problems are caused by environmental
stress. In some cases, poor environmental conditions
(e.g., too little water) damage a plant directly. In other
cases, environmental stress weakens a plant and makes
it more susceptible to disease or insect attack.
 Environmental factors that affect plant growth include
light, temperature, water, humidity, and nutrition

8.  (H2O) is a very important abiotic factor
 it is often said that “water is life.” All living
organisms need water.
 Plants must have water to grow. Even plants that live
in the desert need a little bit of water to grow.
 Without water, animals become weak and confused,
and they can die if they do not rehydrate.

10.  It is the main source of energy on Earth, which makes it
an extremely important abiotic factor.
 Sunlight is necessary for photosynthesis, the process by
which plants convert carbon dioxide (CO2) and water to
oxygen (O2) and sugar food for the plants that later
becomes food for animals.
 Without the sun, plants could not live, and without
plants, animals could not live
 The sun’s heat is also extremely important

11.  Oxygen (O2) is another important abiotic factor for
many living organisms
 Without oxygen, Respiration is no possible for living
organisms
 Carbon Dioxide(CO2) is another important abiotic
factor for many living organisms.
 The green plant are made their food by
Photosynthesis that’s must need carbon dioxide

13.  Topography is a non living factors that’s refers to the
“lay of the land”.
 It includes the physical factors of the earth such as the
land elevation slope terrain (flat, rolling, hilly etc.),
mountains ranges and body of water.
 The altitude of the elevation of the land with respect to
the level of the sea surface influences plant growth &
development primarily through temperature effect.

14.  Soil is often considered an abiotic factor since it is
mostly made up of small particles of rock (sand and
clay)
 mixed with decomposed plants and animals.
 Plants use their roots to get water and nutrients from
the soil.
 Soils are different from place to place so this can be a
big factor in which plants growth of a certain area
depend

16.  This abiotic factor influences all the plant growth processes such
as photosynthesis, respiration, transpiration, breaking of seed
dormancy, seed germination, protein synthesis.
 “Plants survive within a temperature range of 0C to 500 C”
(Poincelot 1980).
 The favorable or optimum day & night temperature range for
plant growth and maximum yields varies crop species.
1. Minimum Temperature: 5.5 0C
2. Maximum Temperature: 55 0C
3. Optimum Temperature: 23-28 C

18. Germination
 The temperature required for germination varies by
species.
 Generally, cool-season crops (e.g., spinach, radish, and
lettuce) germinate best at 55° to 65°F
 While warm-season crops (e.g., tomato, petunia, and
lobelia) germinate best at 65° to 75°F.

20.  Biotic factors are all of the living things in an
ecosystem, such as plants and animals
 These living things interact with one another in many
ways
 Biotic factors and their interactions can be broken
down into three groups:
1:Producers
2:Consumers
3:Decomposers

22.  All plants, such as grass
and trees, are producers.
 These organisms absorb
the sun energy and
convert the energy into
food for themselves,
allowing them to grow
larger, make flowers and
seeds
 The other organisms of
trophic level get energy
by them

23.  These organisms, mostly animals, eat producers or other animals
 They may also eat decomposers.
 Two examples of consumers are deer (eat plants) and wolves
(eat animals).
 Consumers that only eat plants (herbivores) are often known as
primary consumers.
 Consumer that eat both plant and animal is known as secondary
consumer(omnivore)

25. Decomposers
 These organisms break down dead material (such as a
fallen tree) into soil and return nutrients to the soil
 so they can be re-used by producers to create food
 An example of a decomposer is a mushroom

26.  The effects of these living factors on plant expression
may be advantageous or disadvantageous depending
on how they interact with plant.
 These interaction include :
1. Parasitism
2. Mutualism
3. Herbivory
4. Allelopathy

27.  It is a relationship between species, where one
organism, the parasite, lives on or in another
organism, the host,
 Causing it some harm, and is adapted structurally to
this way of life.

28. Vampire parasitic plants ‘sweet
talk’ victims via DNA
communication

29.  Mutualism or interspecific cooperation is the way
two organisms of different species exist in a
relationship
 In which each individual fitness benefits from the
activity of the other
 Similar interactions within a species are known as co-
operation

31.  In Herbivory, plant eating organisms called herbivore
 Such as ruminant animals, rodents, insects, and molluscs feed on
plant parts.
 Herbivores with significant deleterious affects on crop growth
and yield are called pest.
 Damage caused by these biotic factors are varied such as death
of the entire plant or organs, reduced root, stem, leaf or
inflorescence mass, total defoliation, bores and holes on plant
parts, and other marks of feeding.

33.  Allelopathy is a biological phenomenon by which an
organism produces one or more biochemicals that
influence the germination, growth, survival, and
reproduction of other organisms
 These biochemicals are known as allelochemicals
 They can have beneficial (positive allelopathy)
 They can be detrimental (negative allelopathy)
effects on the target organisms and the community

34.  Thermoperiod refers to daily temperature change
 Plants grow best when daytime temperature is about
10 to 15 degrees higher than night time temperature
 Under these conditions, plants photosynthesize (build
up) and respire (break down) during optimum
daytime temperatures and then respiration at night

35.  Temperatures higher than needed increase respiration,
sometimes above the rate of photosynthesis
 Thus, photosynthates are used faster than they are produced.
For growth to occur, photosynthesis must be greater than
respiration
 Daytime temperatures that are too low often produce poor
growth by slowing down photosynthesis
 The result is reduced yield ( fruit or grain production)

36.  Some plants that grow in cold regions need a certain
number of days of low temperature (dormancy)
 Knowing the period of low temperature required by a
plant, if any, is essential in getting it to grow to its
potential
 Peaches are a prime example; most varieties require
700 to 1,000 hours between 32° and 45°F before
breaking their rest period and beginning growth
 Lilies need 6 weeks of temperatures at or slightly
below 33°F before blooming

37.  Most growing plants contain about 90 percent water. Water plays
many roles in plants
 It is a primary component in photosynthesis and respiration
 Responsible for turgor pressure in cells. Turgor is needed to
maintain cell shape and ensure cell growth
 A solvent for minerals and carbohydrates moving through the
plant
 Responsible for cooling leaves as it evaporates from leaf tissue
during transpiration
 A regulator of stomatal opening and closing, thus controlling
transpiration

38.  Plant nutrition refers to a plant's need for and use of basic
chemical elements
 Fertilization is the term used when these materials are added to
the environment around a plant
 Plants need 17 elements for normal growth. Three of them--
carbon, hydrogen, and oxygen--are found in air and water. The
rest are found in the soil
 Six soil elements are called macronutrients because they are
used in relatively large amounts by plants
 They are nitrogen, potassium, magnesium, calcium, phosphorus,
and sulfur