Downy mildew

Downy Mildew on roses, which is also known as Peronospora sparsa, is a problem for many rose gardeners. Roses affected by rose downy mildew will lose beauty and stamina.
Symptoms Of Downy Mildew On Roses ...

Downy Mildew: Downy mildew is a very serious disease that spreads rapidly and can defoliate a rose plant in days. It is not as common as Black Spot and favors cool, wet weather.

Downy mildew Leaves have yellow spots with fuzzy, purple growth on the undersides. Purplish lesions then form on leaves and stems, which become covered with a downy, white fungus. Plants soon die. Remove infected plants.

DOWNY MILDEW - A certain kind of mildew caused by a special fungi. Often confused with sooty mildew and powdery mildew. As with all mildews it is a problem in hot and humid weather. And, like many fungi it transports its spores.

Downy mildew (Blue mold), in many forms, is the primary disease you need to watch out for.

Powdery and downy mildew are common plant diseases for this vegetable.

There are two types: downy mildew and powdery mildew. If the plants are overcrowded and/or short of water, they are much more likely to suffer from diseases in general, and mildew in particular.

In humid areas, mildew diseases can be a problem; European grapes are very susceptible to downy mildew, for example. Black rot, caused by a fungus, develops in warm, moist climates of Eastern states.

Fungi cause root and neck rot, downy mildew, and other common diseases. Prevent these nasty plant diseases by keeping onion leaves dry and ensuring that the soil drains well.

In Everett's Southern backyard, steamy, humid summers provide prime conditions for the most devastating of the rose diseases: black spot, downy mildew and powdery mildew.

Botrytis, Downy Mildew and Purple Blotch of Onion
insect Control: Soaps and Detergents
Mulches for Home Grounds
Vegetable Garden: Soil Management and Fertilization
Choosing a Soil Amendment
Storage of Home-Grown Vegetables ...

Also, when subjected to extensive humidity and moisture, the kale becomes susceptible to a fungal disease known as downy mildew. Keeping optimal growing conditions constant will keep the kale from falling prey to either of these too often.

Indications of too much humidity: Downy mildew
Indications of inadequate humidity: Sluggish growth; yellowing leaves; brown leaf tips and margins; leaf curling; leaf drop; flower bud drop; dry, brittle leaves ...

It likes full sun but will tolerate partial shade. If downy mildew or leafspot become serious problems, especially in humid climates or seasons, spray with a fungicide to protect the plants. Veronica seldom needs staking, and is hardy to Zone 4.

A variety of plant diseases can afflict your grapes. They include powdery and downy mildews, viruses, and black rot. Use fungicides early. Apply before humid weather sets in.
Harvesting: ...

We've all seen rose leaves with black spot or downy mildew. The best thing you can do is get rid of the unhealthy foliage, not only on the plant but that which has fallen to the soil as well.

Pests: Four-lined plant bug. Diseases: Downy mildew
Powdery mildew
Leaf spot
Varieties ...

While lettuces are prone to a few fungal diseases, such as damping off, bottom rot and downy mildew, these problems are relatively uncommon. If they do occur, it's likely to be during a time of cool, damp weather.

Powdery mildew, rust, Botrytis gray mold, downy mildew
How Often to Apply
Every 7-14 days ...

Vine has high vigor, requires no spraying against powdery mildew, but may need a couple of sprays for protection against downy mildew if season is unusually wet.

See also: Mildew, Plant, Gardener, Water, Soil