lecture 10

lecture 10 - 9/17/10 Introductory Plant Pathology BTNY...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 9/17/10 Introductory Plant Pathology BTNY 301 R. D. Martyn Fall, 2010 Lecture #10 The Oomycota Damping off and Downy mildew RD Martyn, Purdue University 1 Diseases caused by the Oomyctoa •  ________________spp. (P. aphaniderma-um, P. debaryanum, P. ul-mum) – 120 different species of Pythium. •  __________________ and ___________________ species •  Cause many different types of diseases –  ______________________________________ –  ______________________________________ –  ______________________ –  ______________________ •  Occur every where in the world •  Hundreds of plant species are suscepUble RD Martyn, Purdue University 2 1 9/17/10 Damping Off and Fruit, Seed & Root Rots (____________spp.) Plant Management Network® RD Martyn, Purdue University 3 Disease cycle of Pythium sp. From G.N. Agrios, Plant Pathology, 5th ed. RD Martyn, Purdue University 4 2 9/17/10 Management of damping ­off / seed decays / root & fruit rots •  •  •  •  •  •  •  •  ______________________ Avoid planUng in ______________ Avoid __________________in soil ___________________ of soil ___________________ of soil ____________________________ ____________________ with antagonisUc organisms ____________________ 5 RD Martyn, Purdue University Downy Mildews •  •  •  •  •  Downy mildew of ___________ (Plasmopara vi-cola) Downy mildew of ___________ (Bremia lactucae) Downy mildew [blue mold] of________ (Pernospora tabicina) Downy mildew of __________ (Pseudoperonospora cubensis) Downy mildew [yellow tu`] of ____________(Sclerophthora macrospora) –  All are ______________ and require _______________ environmental condiUons for severe infecUons. –  Disease cycle similar to Phytophthora and Pythium –  Produce ______________, __________________, & ______________ –  All are ______________________ –  All can spread very quickly, in a few days RD Martyn, Purdue University 6 3 9/17/10 Downy mildew of __________ (Pseudoperonospora cubensis) •  Life cycle is very similar to Pythium spp. •  Only _______________ are affected, but can be quite severe. •  Most cucurbits are suscepUble (watermelon, cantaloupe, cucumbers, pumpkins). •  Many ______________ and ______________ •  Disease is favored by ________,_________ weather RD Martyn, Purdue University 7 Downy mildew of ______________ Egel, Dan. 2008. Downy mildew of pumpkin. BP ­140 ­W hfp://www.ces.purdue.edu/extmedia/menu.htm RD Martyn, Purdue University 8 4 9/17/10 Management of Cucurbit Downy Mildew •  Pathogen ______________________________. ________________________________________ •  _______________________ varieUes when available •  Proper Uming of _________________ applicaUons –  Chlorothalonil •  __________________ ­ PredicUng when the environmental condiUons, inoculum source and host plant will all be favorable for infecUon. RD Martyn, Purdue University 9 Downy Mildew of ___________ (Plasmopara vi-cola) Ash, G. 2000. Downy mildew of grape. 2000. The Plant Health Instructor. DOI: 10.1094/PHII-2000-1112-01 http://www.apsnet.org/Education/lessonsPlantPath/GrapeDowny/default.htm RD Martyn, Purdue University 10 5 9/17/10 Downy Mildew of Grape V.R. Prakash RD Martyn, Purdue University 11 Downy mildew of grape (Plasmapora vi-cola) _____________ _________ _________ ____________ ____________ ____________ ____________ __________ __________ ___________________ RD Martyn, Purdue University 12 6 9/17/10 Pierre Marie Alexis Millardet (1838 – 1902) •  Studied botany under A. de Bary •  Became professor of botany at Bordeaux, France (1876) •  Discovered “____________________” (1882)  ­ the first __________________ to control a plant disease (downy mildew of grape) Ca(OH)2 + CuSO4  ­ ­ ­> ________ + CaSO4 [ lime + copper sulfate cupric hydroxide + calcium sulfate] RD Martyn, Purdue University 13 _________________ mixture on grapes Mercíia variety, Spain RD Martyn, Purdue University 14 7 9/17/10 Downy mildew of grape •  All __________________________ are suscep*ble (cabernet sauvignon, chardonnay, merlot, pinot noir, syrah, etc.) •  Timely applica*on of _______________ only pracUcal control –  Mancozeb, Bordeaux mixture, fixed coppers, Captan (_____________) –  Ridomil® [metalaxyl] (_______________________________) •  _____________________ to remove overseasoning inoculum (_____________________) RD Martyn, Purdue University 15 Downy Mildew of ______________ (Yellow Tu`) (Sclerophthora macrospora) •  Most turfgrasses are suscepUble (rye, blue, fescue, etc). •  Mostly a problem on _____________ e.g., turf mowed to <1” (golf greens). •  Occurs most on _____________________________ •  Increases damage caused by other stress (drought, heat, traffic, etc.) RD Martyn, Purdue University 16 8 9/17/10 Downy mildew of turfgrass (yellow tu`) RD Martyn, Purdue University 17 Downy mildew of turfgrass (yellow tu`) N. Jackson. Yellow tu` or downy mildew of turfgrass. RPD #415. University of Illinois Extension. A. ______________ with ______________ C. _______________ RD Martyn, Purdue University 18 9 9/17/10 Management of Yellow Tu` •  Avoid __________________; ___________________ •  Use ___________________________ •  Mow only when _________________ •  _______________________ in the middle of the day (early morning or night) •  Remove ___________________ •  __________________________ – metalaxyl (Subdue®) RD Martyn, Purdue University 19 10 ...
View Full Document

Ask a homework question - tutors are online