Notes
Photosynthesis
Seed To Fruit No. 2
The yield of vegetables ultimately depends on the size and efficiency of their
photosynthetic system. Crop management practices geared to increase yield are
based on this assumption. Since photosynthesis is the basis of good vegetable
production, it is important to know the processes involved and how the different
plant parts act together to make its own food from the sun and everything around it.
Sunlight
enters the leaf
Food is sent to other
parts of the plant
through Respiration
Water enters
from the stem
(thru the roots)
Carbon Dioxide
enters through the
stomata
Oxygen comes out
through the stomata
Photosynthesis is the process by which carbohydrates and energy-rich chemicals
are formed from carbon dioxide and water, using light energy from the sun with
the release of oxygen. In simple form, the process could be represented as:
light
CO2 + H2O
CH2O + O2
chlorophyll
On the surface of the leaves are many tiny openings called stomata. Carbon
dioxide (CO2) enters through it while O2 that is a by-product of photosynthesis
exits through it.
The components essential to Photosynthesis are:
Light. The greater the intensity and the longer the duration of sunlight, the more chance there is
for the leaves to capture sufficient amount of light energy.
Leaves. While sunlight is available, the plants must have leaves to capture the sun’s energy or it
will be lost. The greater the leaf area, the better the photosynthetic rate. Anything that will
reduce the effective leaf area will also reduce photosynthesis. Insect-damaged leaves have
reduced leaf area, while shaded leaves have lesser effective leaf area. The chlorophyll in the
leaves must also be present in sufficient quantity in order to trap optimum amount of light.
Carbon, hydrogen, oxygen, nitrogen, magnesium and iron are needed for the synthesis of
chlorophyll.
Carbon Dioxide. When the leaves are coated with dust or molds and when the stomata are
closed because of high temperature, CO2 cannot get into the cells.
Practical Application
Photosynthesis is not the
function of the leaves only.
Every part of the plant
takes part in successful
photosynthesis – the roots
provide the water needed,
the stem transports the
water and food around the
plant, even the enzymes in
the plant are important to
this single process in plant
growth.
It is the same in any
organization or business.
Every part of the
organization is important;
no one is better than the
other. Everyone must be
healthy so that the whole
body is healthy. Therefore,
we should do everything
necessary for unity.
Water. Water is a major raw material for photosynthesis; the process will slow down if the amount available for photosynthesis is not
optimum. In addition, lack of water will cause the closing of the stomata, thus CO2 cannot get
into the leaf and oxygen cannot go out, consequently slowing down photosynthesis.
Notes
Enzymes. Although photosynthesis appears to be a simple reaction, it is actually composed of
many chemical reactions, each being triggered and sped up by an enzyme. For enzymes to be
manufactured and to function, some nutrients have to be present in adequate amounts: carbon,
hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, iron, magnesium, chlorine,
molybdenum, boron, sulfur, copper, zinc, and manganese.
The solar energy that a plant stores in carbohydrates during photosynthesis is
used to run and maintain processes in the plants, such as absorption of water &
nutrients, transporting them to leaves, and converting other products of
photosynthesis to cell walls and other cellular parts; so that the plant can grow and
develop. For the carbohydrates to be utilized, their energy must be released in the
process of respiration.
 The products of photosynthesis are the raw materials for respiration and the
fuels for work in the plant are the products of respiration.
 While photosynthesis is a building up reaction, respiration is a breaking
down reaction. However, it is not the reverse of photosynthesis
Practical Application
 The product of photosynthesis may be used immediately or stored as starch.
They may also be converted into more complex compounds, such as cellulose,
proteins, fats, pigments, flavor components, and many other kinds of
compounds.
 This is accomplished by joining several units of glucose, converting them into
sugars, then joining the converted sugars or adding other nutrient elements to
the above substances to form new compounds.
 The energy will come from the breakdown of the simple substances into
carbon dioxide, water and heat. Collectively all these transformations are
called metabolism.
Respiration involves the release of energy from carbohydrates:
A plant makes its own
food, through the process
of photosynthesis. Then,
for the food it makes, it
grows itself strong through
the process of respiration.
It uses the food it produces
to first grow itself – more
roots, more leaves, stronger
stem, etc. It delays its
fruiting to the proper
season when it has become
mature and strong.
Delaying fruiting is like
delayed gratification in
business. As an
organization grows, it must
first use what it produces to
grow itself internally. In
the proper season, like a
plant, it will bear fruit. But
it must first spend its
energy and resources in
growing a health body and
a strong organization.
CH2O + O2
CO2 + H20 + energy
The rate of respiration increases rapidly with the increase in temperature.
Respiration has to be reduced when storing seeds or vegetables for long periods of
time. Reducing temperature and excluding oxygen will slow down respiration.
Notes
Stages Of Growth And Development
The growth and development of a plant occur in three stages: vegetative,
reproductive and terminal. The final stage is the terminal stage where the process
of aging is irreversible and leads to the death of the plant.
A. Vegetative Stage is the juvenile phase when the plant is too young to produce
flowers & fruits – the plant cannot be readily made to flower.
The early period in the growth of the seedling is largely devoted to the
development of a deep root system. Water and nutrients are absorbed through
the root hairs, which are hair-like extensions of the root cells. As the plant
grows, the root hairs in the older parts die, others develop on the younger parts
of the root. The part of the root most active in the absorption of water and
nutrients is the root tip, and the root has to grow continually to provide the
necessary water and nutrients to the plant.
B. Reproductive Stage is the period from flowering to fruit harvest
Flowering. The flower is the reproductive organ of the plant. A plant will
flower to produce seeds that will reproduce the plant. It will flower when it has
produced a minimum amount of vegetative growth.
Pollination. A flower is pollinated when the pollen is transferred from the
anther to the stigma. Inadequate pollination results in misshapen fruits. Some
plants are self-pollinated, while others are cross-pollinated.
Fruit Growth and Development. The developing fruit should be supplied
with a certain amount of food & water; otherwise, the fruits may fall off. A
fruit is a special storage container that the plant uses to store the excess food it
has developed. This happens when the plant has gone through the necessary
stages of its growth.
Temperature and light intensity are important factors that affect the different stages
of growth of a plant. Fruiting trees normally prefer the temperature and condition
from 0 to 500 meters above sea level, while vegetables prefer the conditions around
1000 meters above sea level.
Practical Application
You cannot make a plant
flower in the vegetative
stage or make it bear fruit
when it has not yet gone
through the necessary
stages of growth. When
you try to do this by
inducing it with special
fertilizers, you either kill it
or shorten its life. If you
should be able to get
flowers and fruits by
inducing it, they will not be
healthy.
In the same way, any
business or organization
should go through the
different stages of growth
before it can expect to bear
fruit. When it is still young,
it must concentrate on
growing its roots and
strengthening itself. Do not
induce it with consultants
and systems that will force
it to grow beyond its stage.