Diseases of Wheat

1. Welcome…

2. UNIVERSITY OF AGRICULTURAL SCIENCES PAT.301(2+1 ) DISEASES OF FIELD CROPS AND MANAGEMENT TOPIC : FUNGAL DISEASES OF WHEAT BY, NAGENDRA ALB2099

3. FUNGAL diseases of WHEAT Major Fungal disease in wheat………. RUSTS A. Stem rust B. Leaf rust C. Stripe rust LOOSE SMUT KARNAL BUNT POWDERY MILDEW FOOT ROT LEAF BLIGHT

4. Rusts Three forms rusts can affect wheat (all fungal forms) Stem rust Leaf rust Stripe rust

5. BLACK or STEM RUST Pathogen : Puccinia graminis tritici Uredospores are brown and oval Each cell of teleutospore has one pore Size is about 25-30x15-20µm

6. SYMPTOMS: Reddish brown pustules The large number of uredosori burst, release their spores Infected parts bursting to expose a mass of brown uredospores Brownish appearance even from a distance

7. Favorable conditions Temperature: Between 23-25° C In this condition large number of teliospores are produced. Alternate hosts Berberis , Mahonia and Mahoberberi s

8. Leaf Rust ( Brown or Orange Rust ) Pathogen : Puccinia recondita The pathogen is macrocyclic rust. Uredospores are brown and spherical 16-28um in diameter

9. SYMPTOMS: The black telial pustules are usually formed on the dorsal side of leaves The pustules burst early with mild displacement of the host epidermis And deeply embedded into the host.

10. Stripe Rust(yellow rust) Caused by : Puccinia striiformis Uredospores are spherical to ovate in shape Uredospores are orange colored. Size measuring from 23-35x20-35µm Teleutospores are dark brown and flattened at the top when in contact with the epidermis

11. Symptoms appear early in the spring. Rust pustules are yellow. Spores are blown in from warmer areas. Disease development is most rapid under cool, wet weather.

12. Alternate hosts Agropyron , Bromus etc. Favorable conditions Temperature: 10-15 °C

13. Difference between stripe rust and leaf rust

14. Loose smut of Wheat Pathogen : Ustilago tritici (=U. nuda tritici ) The teliospores are single celled and formed irregularly from fertile hyphae . Teliospores are olivaceous brown, spherical to oval Measures 5-9µm in diameter

15. SYMPTOMS : Can only be seen at the time of flowering though the plants are infected right after seed germination. Ears of infected one emerge early than healthy one. and transformed into black powdery mass Whole ear is covered by delicate silvery membrane. Resulting in formation of very dark olive brown powdery mass

16. Kernel bunt Pathogen : Neovassia indica Spores are smooth walled Measuring 22-49µm in diameter Requires long rusting period The primary sporadia are needle shaped and flexible The secondary sporadia are sickle shaped

17. SYMPTOMS: Plants ripen early than the healthy one Ears are dark green The glues are pushed apart by the spore balls which are formed instead of kernels

18. POWDERY MILDEW Pathogen : Erysiphe graminis var. tritici The conidia are elliptical, hyaline, single celled, thin walled and produced in chains Fungus produce septate , superficial, hyaline mycelium on leaf surface with short conidiophores

19. SYMPTOMS: Greyish white powdery growth appears on leaf, sheath, stem and floral parts Powdery growth later become black lesion and Drying of leaves and Other parts

20. Fungus remains infected in plant debris as dormant mycelium Favorable temperature is 20-21°C and High RH

21. FOOT ROT Pathogen: Pythium graminicolum and P. arrhenomanes This fungus produces sporangia, zoospores and oospores.

22. SYMPTOMS: The disease mainly occurs in seedlings Roots and rootlets become brown in color Seedlings becomes pale green and have stunted growth Wet weather and high rainfall is favorable