WHEAT WHEAT LEAF RUST (caused by Puccinia

triticina)
Kingdom: Plantae Kingdom: Fungi
Phylum: Angiosperms Phylum: Basidiomycota (Club fungi)
Class: Monocots Class: Pucciniomycetes
Order: Poales Order: Pucciniales
Family: Poaceae Family: Pucciniaceae
Genus: Triticum Genus: Puccinia
Species: Triticum aestivum Species: Puccinia triticina
IDENTIFICATION

Leaf rust is caused by the fungus Puccinia triticina.

Leaf rust, like other cereal rusts, requires a living host to survive from one season to the next.
The most important host for rusts are susceptible volunteer wheat plants growing during the
summer and autumn. Rust cannot carry over from one season to the next on seed, stubble or
in soil. Leaf rust is a relatively easy disease to diagnose as it forms orange-brown pustules
that are raised above the leaf surface. These pustules can be rubbed off the leaf leaving an
orange-brown mark on the finger.The pustules scattered across the leaf surface are circular to
oval in shape, and confined chiefly to the upper surface of the leaf. Later in the season, black
teliospores develop on mature plants, usually on the under surface of the leaf or on the leaf
sheath. Heavy infection can lead to premature leaf senescence, reduced photosynthesis and
decreased yield.
Rust spores are wind-blown and can be spread over large areas in a short time. The
establishment of leaf rust epidemics within a crop is favoured by wet conditions and
temperatures of in the range of 15-22°C.

PREVENTION STRATERGIES

Use Resistant Varieties: Plant wheat cultivars that are resistant or moderately resistant to
leaf rust. Consult local agricultural extension services or universities for information on
recommended resistant varieties that are adapted to your region.

Crop Rotation: Practice crop rotation with non-host crops to disrupt the life cycle of Puccinia
triticina and reduce inoculum buildup in the soil.

Proper Crop Spacing: Maintain adequate spacing between wheat plants to promote good air
circulation can reduce humidity levels and minimize conditions favorable for rust
development.

Timely Planting and Seed Treatment: Plant wheat at recommended times to avoid peak
periods of rust infection. Consider treating seeds with fungicides or seed treatments to
protect seedlings from early infections.

Field Hygiene: Remove and destroy volunteer wheat plants and crop residues after harvest to
reduce the survival of fungal spores between seasons.

Treatment Strategies:
Fungicide Applications: Apply fungicides preventatively or curatively based on disease risk
and severity. Consult local agricultural authorities for specific fungicide recommendations
and guidelines on application timing. One of the fungicides commonly used to treat wheat leaf
rust is triazole fungicides, such as propiconazole or tebuconazole.

Scouting and Monitoring: Regularly scout wheat fields for early signs of leaf rust. Monitor
disease progression and make informed decisions regarding fungicide applications based on
disease severity thresholds.
Integrated Disease Management (IDM): Implement integrated disease management
practices that combine cultural, chemical, and biological approaches. This may include
combining resistant cultivars with fungicide applications and cultural practices.
Folicar Nutrition: Apply foliar nutrients to enhance plant health and improve tolerance to
diseases like leaf rust. Balanced nutrition can support plant vigor and reduce susceptibility to
infections.
Genetic Resistance Development: Support research and breeding efforts aimed at
developing wheat varieties with durable resistance to leaf rust. Long-term solutions involve
breeding for genetic resistance that can withstand evolving pathogen populations
 BARLEY BARLEY YELLOW DWARF DISEASE

Kingdom: Plantae Family: Luteoviridae

Phylum: Angiosperms Genus: Luteovirus
Class: Monocots Species: Barley yellow dwarf virus
Order: Poales
Family: Poaceae
Genus: Hordeum
Species: Hordeum vulgare
IDENTIFICATION
The virus is usually spread by aphids from infected grasses to crops. Wet summers and
autumns promote growth of host grasses and build-up of aphid vectors resulting in early crop
infection, severe symptoms and yield losses. Yellow dwarf viruses (YDV) tend to be more
serious in the high rainfall cropping regions

Symptoms take at least 3 weeks to appear after infection. They usually appear as patches of
yellow or red stunted plants. The symptoms first appear where aphids have landed. Flying
aphids may infect individuals or groups of plants dotted throughout the crop. If the aphids
colonise the crop rings or patches develop which increase in size with time If crawling aphids
move into the crop from adjoining pastures or crops then symptoms will appear along the
fence line first.

YDV symptoms can be variable and can differ with host species, cultivar and time of
infection. Sometimes, infection of cereals may occur without visible symptoms. However,
distinct symptoms usually occur on cereals although many infected grasses are
symptomless.Symptoms include yellowing of the leaves, starting at the tip of the leaf and
moving towards the base, resulting in brilliant yellow coloration of the leaves and interveinal
chlorosis.

Early severe infections can lead to:

  stunting
 abortion of florets
 delayed maturity
 shrivelled grain.

PREVENTION

Use Resistant Varieties: Plant barley varieties that are resistant to BYD, if available.
Consult with local agricultural extension services or breeders for information on resistant varieties
suitable for your region.

Early Planting: Plant barley early in the season to minimize exposure to aphids carrying BYD virus.
Early planting can help crops establish before peak aphid activity.

Aphid Management: Monitor aphid populations regularly using yellow sticky traps or sweep nets.
Implement cultural practices such as weed control and removal of alternative host plants to reduce
aphid populations.
Consider applying insecticides when aphid populations reach economic thresholds, especially during
critical growth stages of barley.

Crop Rotation: Rotate barley with non-host crops to break the disease cycle and reduce buildup of
BYD virus in the soil.

TREATMENT
Chemical Control: In severe cases or when aphid populations are high, consider applying insecticides
targeting aphid vectors. Follow recommended guidelines for timing and application rates to minimize
environmental impact and preserve beneficial insect populations. Insecticides such as imidacloprid
or thiamethoxam. These insecticides are not antiviral agents.

Nutritional Management: Maintain optimal soil fertility and provide balanced nutrition to promote
plant vigor and tolerance to diseases like BYD.

Integrated Pest Management (IPM): Adopt an integrated approach that combines cultural practices,
resistant varieties, and judicious use of insecticides based on monitoring and thresholds.

Monitoring and Follow Up: Continuously monitor barley fields throughout the season for signs of
BYD and adjust management strategies accordingly.