How to Identify and Manage Downy Mildew in Lettuce

In greenhouses, followers can additional decrease humidity and forestall extended leaf wetness.

Bodily

If the illness is caught early and restricted to the outer leaves, eradicating the symptomatic tissue can sluggish its unfold. In some circumstances, this can be sufficient to salvage the crop.

Nevertheless, leaf elimination alone is just not a treatment. Mix it with preventative measures or natural remedies to scale back the prospect of reinfection.

Organic

Remedy works finest once you use it preventatively or on the primary signal. As soon as the illness advances, your choices are restricted.

The next merchandise are extremely efficient as preventatives, however gained’t work so properly if the illness is already established.

At all times observe label instructions, as producers present particular protocols for concentrating on this illness.

Streptomyces lydicus WYEC 108 is a naturally occurring bacterium that suppresses fungi and oomycetes.

It’s the lively ingredient in merchandise like Actinovate AG that may assist cease downy mildew in its tracks.

Actinovate AG

You’ll find 18-ounce baggage of Actinovate AG at Arbico Organics.

Another choice is Bacillus subtilis pressure QST 713. This helpful bacterium colonizes plant surfaces and outcompetes pathogens with out harming the host.

You’ll find it in merchandise like Serenade ASO.

Serenade ASO

Serenade ASO is out there at Arbico Organics.

Natural Fungicides

Like organic remedies, natural fungicides work finest as preventatives. As soon as downy mildew is current, it’s a lot tougher to cease or management, however that doesn’t imply you shouldn’t attempt.

A close up horizontal image of a hand from the left of the frame holding a spray bottle to spray lettuce in the garden.

Should you see the illness on one plant, deal with all your lettuces, no matter whether or not they’re symptomatic or not.

You can even alternate an natural herbicide with a biofungicide as long as you observe the producer’s instructions fastidiously.

Copper is a widely known fungicide that has been used for many years to suppress fungal and oomycete illnesses.

It damages cell partitions and causes the contents to leak out, killing the pathogen.

A close up of a bottle of Monterey Copper Fungicide isolated on a white background.

Monterey Liquid Copper Fungicide

You’ll find Monterey’s Liquid Copper out there at Arbico Organics.

Sulfur is one other tried-and-true choice. Utilized each two weeks, it might assist suppress outbreaks alongside copper sprays.

Bonide Sulfur Fungicide

You’ll find Bonide Sulfur Fungicide out there from Arbico Organics.

Thyme oil incorporates thymol, which assaults the cell partitions of pathogens, killing them. It’s efficient at treating downy mildew if used on the first signal of hassle.

Guarda

You’ll find Guarda, which harnesses thymol, out there at Arbico Organics in two-and-a-half-gallon containers.

Potassium bicarbonate prevents and suppresses illness by disrupting fungal cell partitions. It’s efficient in opposition to downy mildew in addition to powdery mildew, leaf spots, and botrytis.

Milstop SP

Milstop SP is made utilizing potassium bicarbonate and is out there at Arbico Organics.

Citric acid acts each systemically and on plant surfaces. It may be utilized repeatedly and offers safety in opposition to a number of illnesses, together with downy mildew.

Plus, you’ll be able to spray it as usually as wanted. Search for merchandise like Procidic, which incorporates citric acid.

Procidic

Procidic is out there at Arbico Organics in 32-ounce ready-to-use bottles, or 16-ounce and gallon concentrates.

Along with these merchandise, hydrogen dioxide can also be an efficient remedy choice, usually utilized in rotation with different merchandise.

Chemical Management

For house gardeners, there are not any chemical fungicides that constantly outperform the natural choices listed above.

Persist with these advisable above and make sure to rotate by way of just a few completely different ones to stop the oomycetes from growing resistance.

Out, Rattling Spot!

Downy mildew is distressingly frequent and frustratingly resilient. I hope you by no means must cope with it, however don’t despair should you do.

Even essentially the most skilled growers encounter it on occasion.

A horizontal image of rows of lettuce plants growing in a raised bed.

What sort of signs are you seeing? Are you having hassle figuring out what you’re coping with? Hit us up within the feedback part beneath and we’ll see how we might help.

And for extra details about frequent lettuce issues, have a learn of those guides subsequent: