disease of maize

1. Common Diseases and
Pest of Maize Crop
Supervisor Dr. Muhammad Ahsan
Iram Naurin
2015-ag-6342
M.Sc.(Hons.)Agriculture (PBG)
Department of Plant Breeding and Genetics,
University of Agriculture Faisalabad

2. Content
Introduction
Uses of maize
Diseases caused by Fungi
Diseases caused by Bacteria
Pest
References

3. Maize
 Scientific name Zea mays
 Chromosomes number 2n=20
 Highly cross pollinated crop
 0.5% contribution in GDP , 2.6% to values
addition in agriculture
 Maize contains protein 10%, starch 72%, oil4.8%,
sugar 3%, ash 1.70%, fiber 9.5%, embryo 12%,
endosperm 82% and testa bran 5% .

4. Uses
Maize and cornmeal are staple foods in many
countries all over the world.
The ears can be cooked and eaten as a vegetable
or the kernels can be used to produce a wide
variety of foodstuffs including cereals and flour.
Maize is also a major source of starch, which
can be processed into oils and high fructose corn
syrup.
Maize is also commonly grown as feed for
livestock.

5. Common rust
Puccinia sorghi
• Symptoms
• Oval or elongated cinnamon brown pustules
on upper and lower surfaces of leaves
• pustules rupture and release powdery red
spores
• pustules turn dark brown-black as they
mature and release dark brown powdery
spores
• if infection is severe, pustules may appear on
tassels and ears and leaves may begin to
yellow
• Management
• resistant hybrids
• application of appropriate fungicides may
provide some degree on control and reduce
disease severity

6. Leaf Blight Exserohilum
turcicum , Bipolaris maydis
• Symptoms
• In the beginning elliptical gray-green
lesions on leaves.
• As the disease process lesions become pale
gray to tan color.
• Later stage the lesions looks dirty due to
dark gray spores particularly under lower
leaf surface.
• long, narrow lesions which are unrestricted
by veins.
• Management
• proper tillage to reduce fungus inoculum
from crop debris.
• Crop rotation with non host crop.
• Grow available resistant varieties.
• In severe case of disease incidence apply
suitable fungicide.

7. Anthracnose
Colletotrichum graminicola
Symptoms
• Small oval or elongated water-soaked spots
which enlarge up to 15 mm long appear on
leaves
• Lesions develop a tan center and red-brown or
orange border
• Severely infected leaves on susceptible
hybrids may wither and die
• Fungal fruiting bodies develop on dead
tissues and may produce pink or orange spore
masses
• Management
• Plant hybrids resistant to anthracnose
• rotating crops and plowing crop debris into
soil may help reduce incidence of early
season infections.

8. Charcoal rot
Macrophomina phaseolina
• Symptoms
• usually first apparent at the tasseling stage
• plant stalks become shredded and pith is
completely rotted with stringy strands of
vascular tissue left intact
• small, black fungal fruiting bodies are visible
in the vascular strands and give the tissue a
gray coloration
• fungus grows into internodes of the stalk
causing the plant to ripen early and causing
the stalk to weaken.
• Management
• There are currently no available fungicides to
treat the disease
• avoid stressing plants by practicing good
water management
• rotating crops with small grains may help
reduce disease incidence.

9. Bacterial Leaf Streak disease
Xanthomonas vasicola
• Symptoms
• The infected leaves initially shows narrow
stripes between the veins.
• The initial symptoms are generally confused
with gray leaf spot disease. But the lesions
from bacteria appear brown, orange, and
yellow.
• Also in Bacterial Leaf Streak disease the
lesions show slightly wavy edges as compare
to the smooth, linear lesion margins of gray
leaf spot.
• Management
• Use healthy and disease free seed.
• Remove the infected plant debris and burn
them.
• crop rotation.

10. Bacterial stalk rot
Erwinia chrysanthemi
• Symptoms
• Plants suddenly beginning to lodge through
season
• one or more internodes above soil line turning
brown, water-soaked, soft and slimy
• tissue has foul odor and mushy appearance
• Management
• Plow all crop debris into soil in Fall
• plant corn in well-draining soil to prevent
waterlogged plants.

11. Aphids
• Symptoms
• Heavy infestations can result in curled leaves
and stunted plants
• honeydew secretions promote growth of
sooty mold
• corn leaf aphids are blue-green in color,
peach aphids are green-yellow in color aphids
may transmit viruses when feeding.
• Management
• It is rare for aphids to reach levels that are
damaging to the plant and no control is
generally warranted as insecticide sprays will
not prevent transmission of viruses.

12. Thrips
• Symptoms
• If population is high leaves may be distorted
and curl upwards
• edges of leaves may dry up and are speckled
with black feces
• insects are small (1.5 mm) and slender and
best viewed using a hand lens
• adult thrips are pale yellow to light brown
and the nymphs are smaller and lighter in
color.
• Management
• Avoid planting next to onions, garlic where
very large numbers of thrips can build up
• use reflective mulches early in growing
season to deter thrips
• apply appropriate insecticide if thrips become
problematic
• young plants will recover from damage and
treatment is not often necessary as the thrips
are beneficial for controlling mites.

13. Nematodes
• Symptoms
• Below ground galls on the roots due to female
nematode feeding.
• Above ground the plants are stunted, yellow
and patchy in growth.
• Severely infested plant may die before
harvest.
• Management
• Deep summer ploughing helps in reducing
nematode population.
• crop rotation with nematode antagonistic
plants.
• Grow resistant varieties.
• In severely infected field soil fumigation with
suitable nematicide

14. Mites
Symptoms
• Leaves stippled with yellow
• leaves may appear bronzed
• webbing on underside of leaves
• small kernel size
• mites may be visible as tiny moving dots on the
webs or underside of leaves, best viewed using a
hand lens
• usually not spotted until there are visible
symptoms on the plant
• leaves turn yellow and may drop from plant
Management
• In the home garden, spraying plants with a
strong jet of water can help reduce buildup of
spider mite populations
• if mites become problematic apply insecticidal
soap to plants
• certain chemical insecticides may actually
increase mite populations by killing off natural
enemies and promoting mite reproduction.

15. References
 Anonymous. 2018-19. Pakistan Economic Survey. Ministry of Finance, Economic Advisor’s Wing.
Islamabad.
 Bureau of Chemistry, U.S. 2010. Wiley, Harvey Washington. Composition of maize (Indian corn),
including the grain, meal, stalks, pith, fodder, and cobs. University of California Libraries,
nrlf_ucb:GLAD-151223559.
 CABI Crop Protection Compendium. 2012. Zea mays datasheet.
 Chaudhary, A.R. 1983. Maize in Pakistan. Punjab Agri. Res. Cord. Board, Univ. Agric. Faisalabad,
Pakistan. 312-317.
 D.R. Mills. 2001. Common Corn Rust. Extension FactSheet. The Ohio State University.
 Espinoza, L. and J. Ross. 2009. Corn Production Handbook (Eds.). University of Arkansas
Division of Agriculture Cooperative Extension Service

16. References
 Hooker, A.L. 2012. Corn and Sorghum Rust. DcKalb-Pfizer Genetics, St. Louis, Missouri.
Lipp, P. E., A. E. Dorrance
 Litsinger, J.A. 1978. Insect pest of maize and sorghum. IRRI, Los Banos, Philippines
 Semangun, H. 2004. Plantation Plant Diseases in Indonesia. Gajah Mada University Press. 449
 Sudarma, I. M. 2012. Disease of corn (Zea mays L.) and control mechanisms. Pelawa Sari.
Denpasar.
 Sumartini and S. Hardaningsih. 1995. Corn diseases and their control. In: the introduction of
pest corn and its control. Balittan Malang Monograf 13: 1-14
 White, D.G. 1999. Compendium of Corn Diseases (3rd ed.). The American Phytopathological
Society, USA.