This document provides information about maize (corn) including its introduction, scientific classification, agronomy, cultivation, growth and development stages, types, quality seed production in hybrids, adaptation and production potential, harvesting process, soil tillage, and tillage systems. The key points are: - Maize originated in Mexico and Guatemala and is one of the most important grains worldwide. - Agronomy of maize involves cultivars, planting, fertilization, pest and disease control, and harvesting. Proper cultivation methods are important for high yields. - There are different types of maize classified by color, kernel shape, and texture. Quality seed production requires isolation, land preparation,

1. 1
INTRODUCTION OF MAIZE
Maize or the scientific name Zea mays and also the common name corn is the third most
important grain worldwide, after wheat and rice. It is generally believed that the earliest form of
maize arose from natural hybridization of two or three grasses native to Mexico and Guatemala.
Scientific classification
Kingdom: Plantae
(unranked): Commelinids
Order: Poales
Family: Poaceae
Subfamily: Panicoideae
Tribe: Andropogoneae
Genus: Zea
Species: Z. mays

2. 2
AGRONOMY OF MAIZE
What is the agronomy??
Agronomy is the science and technology of producing and using plants for food, fuel, fiber,
and reclamation. Agronomy includes work in the areas of, plant physiology, plant genetics
meteorology, and soil science. Agronomy is the application of a combination of sciences like
biology, chemistry, economics, ecology, earth science, and genetics. Agronomis ts today are
involved with many issues including producing food, creating healthier food, managing
environmental impact of agriculture, and creating energy from plants. Agronomists often
specialize in areas such as crop rotation, irrigation and drainage, p lant breeding, plant physiology,
soil classification, soil fertility, weed control, insect and pest control.
An agronomist field sampling a trial
plot of flax.
An agronomist mapping a plant
genome.

3. 3
AGRONOMY OF MAIZE
Agronomy of maize consists of cultivars, plant population, soil tillage, fertilisation, weed,
insect and disease control, harvesting, how to cultivate maize, maize planting, quality seed
production in maize hybrids and treatment to maize diseases.
How to cultivate the maize?
The highest weight of maize crop production have found that as compared to rice and wheat.
Maize in the spring crop planting is done that this season of rain may reap. Rain for the crops, so
much as Maize is sensitive to drought are important. Generally, one two or three crops the crop
cultivation is in the rotation.
MAIZE CULTIVATION
Maize thrives best in a warm climate and is now grown in most of the countries that have
suitable climatic conditions. Its growth depends more on high summer temperatures than on a
high mean temperature. It will ripen in a short hot summer and will withstand extreme heat. A
large amount of water is needed during the growth of the maize. Its average maturing period is
relatively short and this makes it possible to grow at fairly high latitudes.
In the United States of America, the maize growing area stretches from approximately 40
degrees South to 45 degrees North. In Europe, maize growing reaches as far North as 46 degrees
on the West coast of France. From this point, the line runs across Europe reaching 50 degrees in
the East before falling, only to rise again in Southern Russia approaching 52 degrees.
The U.S.A. has the highest output of maize amongst the countries involved in maize growing. In
1964 it produced more than half of the total world maize growth, accounting for 104 million tons
grown by the nation. Today the world harvests almost as much maize as wheat.

4. Maize is exceptional in yield per unit area. The harvest may vary from 2.5 to 6 tons per acre
according to the soil and its cultivation. Yields above 7 tons per acre have often been recorded.
4
Cultivation of maize in the following steps :
 Planting :
crop sowing when the crop is planted. In mid-April planting of maize normally is used
for mid-May.
 Silking :
crop cultivation is the most crucial stage. This means crop pollination.
 Doughing :
When maize crop starts to show a thick substance, called crop will doughed.
 Denting :
doughing During the process, like plant material in the formation of the dough spends all
its resources and to reduce the plant and 'one' break begins at end of matter is to show .
The denting thus called.
 Maturing :
When the green leaves of maize leaves and is gone from opening appears, the crop is said
to be mature.
 Collection :
crop generally is mature around 3 -4 months end and then it is ready to be collected or
harvested.

5. 5
TYPES OF MAIZE
There are about 50 different species of maize having their own charac teristic features and kernel
sizes, all belonging to a small number of types. Colour and structure, as well as the shape of the
kernel, differ from one species to another.
White, Red and Yellow are the most common basic colours of maize, but it is possible to find a
wide range of shades, from Red-Brown to Light Red and from a Pale Yellow to Orange.
The shape of the kernel can be divided into two main groups:
Flint maize (round shape) Dent maize (tooth shaped)
Maize Shape Texture
White Flint or Dent Varies
Plata Flint Hard, Glassy
Yellow Mostly Dent Comparatively Soft
In general, the flint glassy-kernel varieties yield better grits than the softer mealy dent maize.
Some products, however, require a raw material of the soft type. For milling purposes the maize
should be dry and bright. Dull colour often indicates that the maize is old or has been harvested
or stored under unfavourable conditions. The germ must be free of mould.
Great importance is attached to the use of sound and fresh grain to give high quality in finished
products. The quality of the maize affects the yield and fat content of the grits or flour much
more than in wheat milling. Different types and qualities of maize undergoing identical grinding
operations will produce grits or flours which vary considerably.

6. 6
TYPICAL COMPOSITION
Endosperm 82%
Germ 12%
Bran 5%
Tip Cap 1%
Total: 100%
TYPICAL ANALYSIS
Components % % Dry Basis
Moisture 9 – 15 --
Starch 61 72
Protein 8.5 10
Fibre 9.5 11
Oil 4 3.4 – 5
Ash -- 1.6

7. 7
QUALITY SEED PRODUCTION IN MAIZE
HYBRIDS
 Suitable climate
In Tamil Nadu, maize is cultivated during June – July, September – October and January
– February seasons. Sowing during November - December is suitable for seed production,
since seed maturity stage will not coincide with rainfall.
 Isolation distance
For this isolate the hybrid seed crop from fields of other maize varieties with same seed
color by 200 m distance.
 Land requirement
Well drained sandy red or black soil is suitable. The selected fields should be free from
volunteer maize plants.
 Seed treatment
To control the fungal disease treat the seed with thiram at 2g kg-1 seed. One day after
treat the seeds with 600 g of Azospirillum with rice gruel and shade dry for 15 minutes.

8. 8
GROWTH AND DEVELOPMENT
Growth stage 0: from planting to see emergence
 During germination, the growth point and the entire stem are about 25 to 40 mm below
the soil surface. Under warm, moist conditions seedlings emerge after about six to 10
days, but under cool or dry conditions this may take two weeks or longer. The optimum
temperature range for germination is between 20 and 30 ºC, while optimum moisture
content of the soil should be approximately 60 % of soil capacity.
Growth stage 1: four leaves completely unfolded
 The maximum number of leaves and lateral shoots is predetermined and a new leaf
unfolds more or less every third day. The growth point at this stage is still below the soil
surface and aerial parts are limited to the leaf sheath and blades. Initiation of tasselling
also occurs at this stage.
Growth stage 2: eight leaves completely unfolded
 During this period, leaf area increases five to 10 times, while stem mass increases 50 to
100 times. Ear initiation has already commenced. Tillers begin to develop from nodes
below the soil surface. The growth point at this stage is approximately 5,0 to 7,5 cm
above the soil surface.
Growth stage 3: twelve leaves completely unfolded
 The tassel in the growth point begins to develop rapidly. Lateral shoots bearing cobs
develop rapidly from the sixth to eighth nodes above the soil surface and the potential
number of seed buds of the ear has already been determined.
Growth stage 4: sixteen leaves completely unfolded
 The stem lengthens rapidly and the tassel is almost fully developed. Silks begin to
develop and lengthen from the base of the upper ear.

9. 9
Growth stage 5: silk appearance an pollen shedding
 All leaves are completely unfolded and the tassel has been visible for two to three days.
The lateral shoot bearing the main ear as well as bracts has almost reached maturity. At
this point demand for nutrients and water is high.
Growth stage 6: green mealie stage
 The ear, lateral shoot and bracts are fully developed and starch begins to accumulate in
the endosperm.
Growth stage 7: soft dough stage
 Grain mass continues to increase and sugars are converted into starch.
Growth stage 8: hard dough stage
 Sugars in the kernel disappear rapidly. Starch accumulates in the crown of the kernel and
extends downwards.
Growth stage 9: physiological maturity
 When the kernel has reached its maximum dry mass, a layer of black cells develops at the
kernel base. Grains are physiologically mature and only the moisture content must be
reduced.
Growth stage 10: drying of kernel (biological maturity)
 Although grains have reached physiological maturity, they must dry out before reaching
biological maturity. Under favourable conditions, drying takes place at approximately 5 %
per week up to the 20 % level, after which there is a slowdown.

10. 10
ADAPTATION AND PRODUCTION POTENTIAL
 Temperature requirement -Maize is a warm weather crop and is not grown in areas
where the mean daily temperature is less than 19 ºC or where the mean of the summer
months is less than 23 ºC.
 Wate r - Approximately 10 to 16 kg of grain are produced for every millimetre of water
used. A yield of 3 152 kg/ha requires between 350 and 450 mm of rain per annum. At
maturity, each plant will have used 250 l of water in the absence of moisture stress.
 Soil requirements - The most suitable soil for maize is one with a good effect ive depth,
favourable morphological properties, good internal drainage, an optimal moisture regime,
sufficient and balanced quantities of plant nutrients and chemical properties that are
favourable specifically for maize production.

11. 11
MAIZE HARVESTING PROCESS
Harvest time
 The optimum time of harvesting maize is when the stalks have dried and moisture of
grain as about 20-17%.
Harvesting process requirement
 Harvest maize as soon as it is dry but not overstay in field it will be attacked by weevils if
does and lodge. In addition to reducing post harvest losses, this will also release the field
for early land preparation.
 Keep the grain as clean as possible. Dry maize on cement floor or use tarpaulin to reduce
chance of contamination.
 At home, do not first heap the cobs in any room, kitchen or in the yard because this will
expose them to all the dangers that cause post harvest losses. Transfer them to the drying
place (like the crib) immediately.
 Dry on concrete or canvas not on bare soil.
Before Harvesting
 Make sure the drying place or equipment is clean and disinfected, ready to receive the
cobs.
 Remove old grain and dirt from anything that will come in contact with the good or new
grain. This includes harvesting tools, carts, wheel barrows, bags and baskets.
 Where possible, fumigate them or at least treat them with boiling water to kill insects or
their eggs. This is done in order to avoid infection of new grain by insects and their eggs.
 Organize enough labour to reap and carry the cobs to the drying place.
After Harvesting
 Drying- the systematic reduction of crop moisture down to safe levels for storage,
usually 12%-15.5% moisture content. It is one of the key post harvest operations since all
down-stream operations depend on it.

12.  Shelling- Shelling is commonly done by beating maize cobs with stick in a sack or a
12
confined floor space where farmers can afford it.
 Storage- to maintain the stored grains in good condition so as to avoid deterioration both
in quantity and quality.
 Spillage
Losses due to poor storage
 Mould
Microbial infection in storage occurs due to inadequate drying of produce. The situation
is made worse when there are large numbers of insects present or when the stored crop is
exposed to high humidity or actual wetting due to poor storage management. Fungal
infection results into rots and development of aflatoxins, which are poisonous compounds
to live stock and cause cancer in human.
Conditions that favour aflatoxin contamination in maize grains
Aflatoxin contamination is encouraged by:
 Physical damage due to poor shelling/threshing methods
 Poor storage methods (exposure to moist condition)
 Insect infestations.
 Inadequate drying
Aflatoxin cannot be seen with a naked eye. However, suspect materials tend to:
 Be rotten
 Be mouldy
 Be discoloured
 Have unpleasant smell
 Have bitter taste
 Have poor milling quality

13. 13
 Be warmer than room temperature.
Losses due to mould
 Loss of weight
 Loss of quality (smell, taste, colour, nutritional value, germination)
 Further increase in temperature and moisture, causing more grain deterioration.

14. 14
SOIL TILLAGE
 Soil tillage, particularly primary tillage, is the foundation of any crop production system
and is the biggest cost factor in maize production.
Primary tillage implements
 Mouldboard ploughs - This implement is used to turn sods up to 300 mm depth and is
particularly useful on heavier well-structured soils. Turning the soil also has the
advantage that weed seeds and unwanted crop residues can be buried deeply. Mouldboard
ploughs are not recommended on sandy soils, because poorly-structured units which may
exist, can be destroyed and wind erosion be promoted.
 Disc ploughs and discs - The disc plough has a slicing action with the main advantage
that better penetration is obtained under dry, hard conditions, with an additional
advantage that wear is lower than in the case of a mouldboard plough. The implement is
useful on hard, dry soils where loss of structure is not too critical. It is on no account
recommended for sandy soils.
 Chisel ploughs - Chisel ploughs are used mainly to loosen the soil to a limited depth of
250 mm. Best results are obtained if the soil is relatively dry, because the chisels break
the soil, creating structural units. If conditions are too dry, however, big clods are formed,
restricting plant development.
 Rippers - Rippers are used when deep cultivation is necessary and turning of the soil is
undesirable. If soils are tilled annually to the same depth, a plough-sole develops. This
confined layer prevents infiltration and root development. To ensure better drainage,
conservation and utilisation of water, it is essential to break this layer regularly. Under
wet, clay conditions, the main disadvantage of the ripper is that it compacts the soil
laterally and inwards, which can limit lateral root development.
Secondary tillage implements
 Rotary tille r - Under ideal conditions, on moist clay soils, this useful implement can
prepare the seedbed in one operation. On dry, sandy soils it can, however, destroy the
structure within a very short period.

15.  Tined cultivators - Tined cultivators include a variety of hoeing implements, which are
used mainly for controlling young weeds, but also utilised for breaking surface crusts.
These implements are only effective on moist soils. They are completely ineffective on
dry, clay soils. These implements are often used for seedbed preparation.
 Harrows - Harrows include a variety of implements. The tined harrow is primarily used
to level the seedbed once it is in a fine condition. The primary objective of the disc
harrow is to break surface crusts, but it can be used to break clods to obtain a fine
seedbed.
15
Tillage systems
 No-till
With this system, soil is left undisturbed from planting to harvesting. A prerequisite for
this type of cultivation is that 30 % of the soil must be covered with plant residue after
planting to reduce water erosion effectively.
 Stubble-mulch tillage
In this case, soil is disturbed before planting without burying or destroying. For this
action chisel ploughs, discs, spring-tooth implements or V-type blades are used. Weeds
are controlled chemically and/or mechanically.
 Reduced tillage
This could be any type of tillage practice which leaves 15 to 30 % of the soil surface
covered with stubble. Weeds are controlled chemically or mechanically.
 Conventional tillage
This includes tillage that leaves less than 15 % of the soil surface covered with stubble.
Conventional tillage usually implies a plough action or an intensive range of cultivations.
It is important to bear in mind that 1 ton of grain/hadelivers one ton of plant residue,
which is sufficient to cover 10 % of the soil. If conservation tillage is considered as an
alternative, a minimum yield of 3,0 ton/ha must be obtained to provide a surface cover of

16. 30 %. When conservation tillage is practised with the aim of conserving moisture, at least
50 to 60 % of the soil surface should be covered. With any tillage system, it is paramount
importance to ensure that a compacted layer, that may impair plant growth, does not
occur in the effective root zone. Any soil has the potential to form a compacted layer and
therefore all cultivated soils should be inspected regularly for such restrictions. If
confined layer is detected, it should be broken using a ripper implement to ensure better
drainage, conservation and utilisation of water.
16

17. 17
PEST AND DISEASES OF MAIZE
EARTHWORMS
This ugly caterpillar can grow to 2 inches and comes in shades of green, pale yellow and
brown. Adults are dull beige or gray moths with a 1½ inch wingspan and a few black
spots. They begin munching the tender shoots as soon as they break ground. They chew
tassels and interrupt pollination and kernel development. Inside the ears they will
consume kernels and leave globs of fecal material.
CUTWORMS
This is a catchall name for the destructive larvae of hundreds of different species of
moths. They are soft, ugly, fat, bristly and of almost any color. Some species climb into
plants to feed, but the classic sing of busy cutworms is seedlings gnawed at the base until
they fall over. Most damage is done at night.
APHIDS
Tiny (less than 1/10 inch) soft bodied pear shaped insects with whiplike antennae. Varied
in color. Leaves turn yellow.
BIRDS
Some birds are nice to have around the garden because they eat insect pests. Others, such
as crows and blackbirds, can be destructive.

18. 18
SOLUTION FOR THE PESTS
PESTS SOLUTION
Earworms  Fall and spring tilling helps by exposing the pupae to
wind, weather, and predators. Early plantings of corn may
avoid damage and cold, damp weather discourages
earworms almost as much as it does the corn.
 Corn varieties with tight husks are physically more
resistant to earworm damage. Try Country Gentleman or
Silver Cross Bantam. Clipping a clothespin on the tip of
each ear can help to keep husks tight.
 Wormwood Spray or a spray made from garlic and onion
tea.
 A drop of mineral oil on the tip of each ear may help to
suffocate any resident earworms. Give the mineral oil by
mixing with pureed African marigolds or geranium leaves.
Do not apply mineral oil until pollination is complete.
 Check the farm supply store to see what insect predators
are available.
 Blacklight traps will destroy earworms, and cosmos,
smartweed and sunflowers are good trap crops.
Cutworm  Till soil as early as it can be worked in the spring and
allow 2 weeks. This removes weed seedlings that the first
wave of larvae depend on for food. Eggs are laid in weeds
and grass. Keep the garden clean.
 Interplant with onion, garlic or tansy to repel cutworms or
plant sunflowers as a trap crop.
 Handpicking is easiest and most productive following a
rain or thorough watering and should be done after dark.
Cutworms can be spotted with a flashlight.
 Placing a cardboard collar around young seedlings

19. presents a barrier that cutworms can't cross. Use a piece of
a toilet paper or paper towel roll or a paper cup with the
bottom torn out.
 Cutworms love cornmeal, but they can't digest it. The
19
cornmeal can be cut with Bt for a fatal feast.
 Molasses mixed with hardwood sawdust is an effective
trap when spread around susceptible plants. The cutworms
will get stuck in the molasses and can be destroyed in the
morning.
 Adult moths are easily killed with bug zappers.
Aphids  Plant alliums such as garlic and chives. Anise, coriander,
nasturtiums, and petunias may be helpful. Use yellow
sticky traps or yellow dishes containing soapy water.
Soap-Shield and mint tea spray is highly effective.
Lacewings will eat 100 aphids per day
Birds  Use netting over the corn row. When harvest approaches,
use net bags over corn ears. Orange and onion bags will
do nicely.

20. 20
DISEASE MANAGEMENT OF MAIZE
DISEASE EPIDEMIOLOGY
Black Bundle Disease and
Late Wilt: Cephalosporium
maydis, Caphalosporium
acremonium
 The disease kills the plant prematurely after flowering.
Infected plants do not show symptoms until they reach to
tasseling.
 Wilting generally starts from the top leaves, Leaves
become dull green, eventually loose colour and become
dry.
 In advance stages the stalk loses its healthy green colour,
lower portions become dry,shrunken with or without
wrinklings, hardens and turn purple to dark brown which
in more prominent on lower internodes.
 When split open diseased stalks, show brown vascular
bundles starting in the underground portion of the roots.
 Diseased plants produce only ears with undeveloped
shrunken kernels.
 In severe cases affected plants remain abortive causing
100 per cent loss.
 Cephalosporium maydis is primarily soil borne and may
infect young maize plants more readily than other plants
through roots or mesocotyl. In case of C.
acremonium only vascular burdles get blackened.
Bacterial Stalk Rot: Erwinia
carotovora, Erwinia
chrysanthemi
 High humidity especially overhead irrigation and
waterloging, coupled with high temperature (30oC and
above), are conducive for disease development.
 The basal internodes develop soft rot and give a water
soaked appearance. A mild sweet fermenting odour
accompanies such rotting.
 Leaves some time show signs of wilting or water loss and

21. affected plants within a few days of infection lodge or
topple down.
 Ears and shank may also show rot. They fail to develop
21
further and the ears hang down simply from the plant
Charcoal-
Rot : Macrophamina
phaseolina
 The disease development is maximum during grain filling
stage and is favoured by warm temperature (30-400C) and
low soil moisture.
 Charcoal rot is found to be prevalent particularly
in rabi season when summer temperatures during post
flowering period becomes comparatively high (35 -
450C).
 Disease cycle
 The pathogen also attack many other hosts, which helps
in its perpetuation. Since the fungus is a facultative
parasite it is capable of living saprophytically on dead
organic tissues, particularly many of its natural hosts
producing sclerotial bodies.
 The fungus over winter as a sclerotia in the soil and
infects the host at susceptible crop stage through roots
and proceed towards stem.
Common Rust : Puccinia
sorghi
 Cold temperature (16-23°C) and higher relative humidity
favor the rust development and spread
Downy Mildews  Downy mildews are an exciting group of fungi which
attacks many economically important crop plants.
 Ten downy mildew diseases are known on maize caused
by two genera viz., Peronosclerospora and Sclerophthera.
 Out of these, Sorghum Downy Mildew and Brown stripe
downy mildew are common in our country.

22. 22
CONCLUSION
Maize is essentially a crop of subtropical regions, but after selecting and breeding, a large
number of cultivars are now also adapted to temperate conditions. However maize has the
characteristic C4 cycle photosynthetic development, which means vigorous growth and high
yields under warm and bright conditions. Maize does not thrive well in semi arid or equatorial
climates. For germination the minimum soil temperature has to be 10o C. for growth and
development the average day temperature should be at least 15o C. It is easily killed by frost.
Maize grows on a wide range of soil types, but prefers deep, naturally rich, easily tilled soil, pH
5.5-6, it is sensitive to salinity. Maize is rather drought-tolerant, however, annual rainfall of at
least 750nm is required for adequate moisture, especially around the time of tasseling and
fertilization, maize plants are very sensitive to water deficiency.
Maize is nearly always planted through direct seeding. Soil temperature has to be about 10oC,
below that temperature the seeds do not germinate until the desired soil temperature is reached. If
that takes too much time, soil pathogens can cause damage to the seeds. The result may be that
the seeds do not germinate at all or produce abnormal seedlings. Plant density depends on
cultivars,cropping system and cropping purpose( for silage, higher density than for the grain),
soil condition and climate, it ranges from 20000 to 100000 plants/ha. Sowing has to be done
carefully because maize has poor tillering capacity, it is mostly not able to fill open spaces in the
field. The seeds have to be placed 2.5-6 cm deep, depending on how deep the moist soil is
located below the dry surface layer.
Maize usually responds well to fertilizer. Each produced tonne of grain removes about 30kg N,
5kg P and 35kg K. How much fertilizer has to be applieds depends on inherent soil fertility.
Modern hybrids only reach their high yield potential when sufficient nutrients are applied. Weed
control will be necessary, especially in the juvenile stage.

23. 23
REFERENCES
1. Ton Elzebroek and Koop Wind (2008) Guide to Cultivated Plants, CAB
International (326-327)
2. Rick Hodges & Graham Farrell (2004) Crop Post-Harvest : Science and
Technology Volume 2 DURABLES, Blackwell Publishing (26-51)
3. R.B.H Wills (2007) Postharvest,. An introduction to the physiology and handling
of fruit, vegetables and ornamentals, CAB International (99)
4. http://en.wikipedia.org/wiki/Maize
5. www.Ikisan.com/maize
6. http://nigeria.thebeehive.org/
7. http://www.gardenguides.com/
8. http://agropedia.iitk.ac.in/