Lettuces Diseases
- Downy Mildew. Downy mildew is a fungus that can affect up to 80 percent of acreage once established.
- Leaf Spot. This disease comes from weeds and typically affects less than five percent of acreage.
- Lettuce Mosaic Virus.
- Tomato Spotted Wilt Virus.
- Bottom Rot.
- Drop.
- Bacterial Diseases.
- Chemical.
What is the most common pest of lettuce?
Caterpillars
Key to Lettuce Pests. Caterpillars attacking the fall crop are usually the most troublesome field pests of lettuce. In the greenhouse, aphid and cabbage looper infestations often give problems. Cutworms, whiteflies, leafminers, and slugs are slightly less important greenhouse pests.
What is the problem of lettuce?
Pests and diseases
Lettuce are attractive to a wide range of pests especially aphids, caterpillars and slugs. The diseases downy mildew, botrytis and sclerotinia are the main problems when growing the crop.
What causes lettuce to decay?
Sclerotinia Drop
Two species of Sclerotinia infect lettuce and cause the lettuce drop disease. Sclerotinia minor only infects the stems and leaves in contact with the soil. Once infection takes place, the fungus will cause a brown, soft decay that eventually destroys the plant crown tissue.
What causes holes in lettuce leaves?
Slugs are the most common cause of holes in leaves, but they often remain unseen because they feed at night. Sometimes larger slugs eat leaves from the edge inward, but small slugs make irregular holes inside leaves, as shown in the chard leaf on the right in the above photo. Slug holes always have smooth green edges.
Does lettuce get fungus?
Downy mildew is a fungus that can affect up to 80 percent of acreage once established. Mature leaves are often most affected by this disease. Lettuce develops a yellow area on the upper side of the leaves and a white or gray fluff on the underside.
What does blight look like on lettuce?
Lesions enlarge, turn brown, dry out and may fall out giving the leaves a tattered appearance. Numerous fruiting bodies (pycnidia) develop with leaf spots. Symptoms of bacterial leaf spot start as small brown spots with chlorotic haloes occurring on the lower leaves first.
Is there a virus in lettuce?
There are several sources of the Lettuce mosaic virus. Since the virus is seedborne in lettuce, infected seed is a primary way of introducing lettuce mosaic to fields. The virus can infect numerous crops and weeds, thereby creating reservoirs of the virus.
What causes yellow leaves on lettuce?
Be sure you’re not keeping the soil too moist – this will lead to root rot which produces yellow plants. Water deeply less often – let the surface of the soil go dry before watering again…a fan will also help with this.
What does Overwatered lettuce look like?
Lettuce is not one of the hardest vegetables to grow, overwatered lettuce is pretty easy to spot; it looks slimy and yucky and yellow, brown, and even black. The lettuce may look like it’s rotting or melting, because more or less it is doing just that.
Why does lettuce get brown spots?
Rust usually occurs near the roots of a head of lettuce. These reddish-brown blemishes can be the result of too much moisture during storage. Although it’s not harmful, it can certainly be unappetizing. It’s best to remove these spots before making a salad.
How do you fix dying lettuce?
Lettuce wilts because it loses water, so the key to reviving it is to put the water back in. We’ve had success simply soaking the wilted leaves in ice water for 30 minutes.
Should I cut off leaves with holes?
Fortunately, there’s good news! Greens with holes in them that were created by feeding insects or slugs should be fine to eat, if you cut away the damaged parts. However, there are times when you do want to avoid produce that has been damaged by the local wildlife.
How do you treat holes in leaves?
For both, treat with insecticidal soap or horticultural oil. Sucking insects poke tiny holes in leaves and draw the juices out of them. Common sucking insects include aphids, squash bugs, and spider mites.
What causes tiny holes in leaves?
Chewing insects eat leaves and make holes by biting or tearing leaves and grinding them with their tooth-like mandibles. Few plants — or plant parts — are safe from damage by chewing insects. Day-feeding Japanese beetles skeletonize the leaves of hundreds of plant species.
What does mold on lettuce look like?
Downy mildew of lettuce is a disease caused by a fungus-like (Oomycete) organism, producing yellow patches and fuzzy white mould on leaves. These patches turn brown as the leaf tissue dies. It affects seedlings and mature plants.
What does powdery mildew look like on lettuce?
The powdery mildew fungus appears as a gray-white, powdery growth on both upper and lower sides of lettuce leaves. Such infections may cause deformity and buckling of the leaves. In advanced stages, leaves may begin to dry out and turn brown.
What does bacterial leaf spot look like?
Symptoms of bacterial leaf spot
Bacterial leaf spot diseases often start as small dark brown to black spots with a halo of yellow tissue surrounding each spot. In some cases, the center of the leaf spot will dry up and fall out, giving the leaf a “shot hole” appearance.
What are the symptoms of bacterial blight?
Symptoms of common bacterial blight first appear on leaves as small, water-soaked spots, light green areas, or both. As these spots enlarge, the tissue in the center dies and turns brown. These irregularly shaped spots are bordered by a lemon yellow ring, which serves as a diagnostic symptom of common bacterial blight.
Is it safe to eat lettuce with bacterial leaf spot?
The lettuce is still safe to eat, though make sure to give it a good rinse. Those spots signal that cells have been weakened, making the lettuce a touch friendlier to any pathogens that happen to be nearby. And prioritize eating this lettuce; the brown spots indicate an accelerated rotting schedule.
How does E. coli get in lettuce?
Romaine lettuce and spinach are grown in the soil, which can be exposed to animal feces or contaminated water. The produce is at risk of contamination from irrigation water especially if it’s grown near animal production facilities where the animals may be infected with E. coli.