DOWNY MILDEW FUNGI PART -3.pptx

THIS part of downy mildew consists of sclerospora and perenosclerospora.

Downy mildew fungi are plant pathogens that cause significant damage to a variety of crops, including grapes, cucumbers, lettuce, and onions. These fungi thrive in cool, moist environments and can spread rapidly through a field, causing devastating losses for farmers.

This slide deck provides an overview of downy mildew fungi, including their life cycle, symptoms, and management strategies. The presentation begins with an introduction to the various types of downy mildew fungi, including the species that affect grapes, cucumbers, and other crops.

Next, the slides detail the life cycle of downy mildew fungi, from spore germination to the development of lesions on plant leaves. The presentation also explains how these fungi spread from plant to plant and from field to field, and highlights the conditions that favor their growth and reproduction.

The slide deck then goes on to describe the symptoms of downy mildew infection, including yellowing and wilting of leaves, stunted growth, and the development of characteristic downy white or gray spores on the undersides of leaves.

Finally, the presentation offers practical tips and strategies for managing downy mildew fungi, including cultural control measures such as crop rotation and sanitation practices, as well as chemical control methods such as fungicides.

Overall, this slide deck provides a comprehensive overview of downy mildew fungi and their impact on agricultural crops, as well as practical strategies for preventing and managing these devastating plant pathogens.

1. ANNAMALAI UNIVERSITY FACULTY OF AGRICULTURE DEPARTMENT OF PLANT PATHOLOGY PAT-501 MYCOLOGY GENERAL CHARACTERS AND LIFE CYCLE OF GENUS PERONOSPORA , PSEUDOPERONOSPORA, PLASMOPARA , BREMIA , SCLEROSPORA , PERONOSCLEROSPORA BY R.LOKESH I -M. sc .,Agriculture Plant pathology Annamalai university TOPIC: Part-3

2. GENERAL CHARACTERS OF SCLERPSPORA

3. GENERAL CHARACTERS OF PERENOSCLERPSPORA

4. Peronosclerospora sorghi Scientific classification Kingdom: Chromista Phylum: Oomycota Order: Peronosporales Family: Peronosporaceae Genus: Peronosclerospora Species: P. sorghi Binomial name Peronosclerospora sorghi (W. Weston & Uppal) C.G. Shaw, (1978)

5. SYMPTOMS  Infected plant chlorotic and sometime stunted, white-stripped leaves & abnormal seed set. The chlorotic area of leaf always includes the base of the blade, and transverse margins usually sharply defined between the diseased and healthy tissues A white, downy growth may appear on both surface of infected leaves. Sometimes tassels of diseased plant may exhibit phyllody. Tolerant plants may show symptoms of systemic infection but have normal seed production .

6. HEALTHY LEAF INFECTED LEAF AND PLANTS

7. Disease Cycle The primary infection is by means of oospores present in the soil which germinate and initiate the systemic infection.  Oospores  persist in the soil for several years. Secondary spread is by air-borne   sporangia . Presence of mycelium of the fungus in the seeds of systemically infected plants is also a source of infection. The disease has been known to occur through a  collateral  host ,  Heteropogen   centortus   on which the fungus perpetuates of the host. The breakdown of tissue causes shredding. The oospores either fall to the soil or are wind blown, often within host tissue. They can remain viable in the soil for 5-10 years.  Conidia   are formed at night in large numbers. The optimum temperature for production is 20-230C.

8. REFERENCES Introductory mycology – Alexopoulos An introduction to fungi – H.Dube https://en.wikipedia.org/wiki/Sclerospora_graminicola https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/sclerospora-graminicola https://en.wikipedia.org/wiki/Peronosclerospora_sorghi https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/peronosclerospora-sorghi https://agritech.tnau.ac.in/crop_protection/maize_disease/maize_1.html https://www.google.com/url?sa=i&url=http%3A%2F%2Foar.icrisat.org%2F1587%2F1%2FISMN37_33-51_1996.pdf&psig=AOvVaw3EqUsmUooztA-jTNKxTOxx&ust=1678078939911000&source=images&cd=vfe&ved=0CBAQjRxqFwoTCPCS3qqBxP0CFQAAAAAdAAAAABAR