Fungal Diseases of Grapevines: Overview

There are so many things to remember about fungal diseases of grapevines so I put it all together in a table so that I could compare the details side by side.

	Downy Mildew	Powdery Mildew	Black Rot	Phomopsis
Latin Name	Plasmopara viticola	Erysiphe necator	Guignardia bidwellii	Phomopsis viticola
Lifecycle	Downy Mildew Lifecycle	Powdery Mildew Lifecycle	Black Rot Lifecycle	Phomopsis and Leaf Spot Lifecycle
Primary Infection	Oospores	Ascospores	Ascospores	Pycnidiospores
Secondary Infection	Zoospores	Conidia	Pycnidia
Overwintering Form	Oospores in fallen leaves Mycelium in buds	Hyphae inside dormant bud scales Cleistothecia on the surface of the vine	Mummies in berries, vine or in the ground	Mycelium and pycnidia in bark Mycelium in dormant buds
Favorable Conditions	Warm and wet conditions Infection generally occurs in the morning	High humitiy, temperatures between 68 to 81 oF Low, diffuse light Shady portions of the vineyard	Temperature and age of tissue when infected	Rainy weather during the early growing season
Method of Distribution	Rain splash Wind	Wind dispersal; does not require rain or water	Rain water	Splashing rain water
Susceptible Tissues	All green parts of the vine esp. leaves Plant structures with stomata are susceptible	All green tissues of the grapevine	All new growth during the growing season All green tissues	Shoots, leaves, rachis
Control of the Disease		Sulfur: both preventive and curative, applied as both dust or as wettable powder
Cultural Practices	Good soil drainage Reduce overwintering inoculum Prune infected shoots	Reduce humidity Get good air circulation in the vineyard Provide good light exposure	Canopy management practices to improve air circulation Remove all mummies during the dormant period	Increase air circulation in the vineyard Remove diseased canes during normal pruning operations
Link to Cornell IPM pdfs	Downy Mildew---Diease Identification Sheet No. 5 1984	Powdery Mildew---Diease Identification Sheet No. 102GFSG-D2 2003	Black Rot---Disease Identification Sheet No. 102GFSG-D4 2003	Phomopsis---Disease Identification Sheet No. 6 Revision 1991

I'm still looking into how to control the diseases organically, so I'll be updating this form. All of the information came from the links to the Cornell IPM pdfs. This form is also located under the tab Fungal Diseases of Grapevines.