Anthracnose

How to Identify and Control Anthracnose

Anthracnose-CSIRO Scienceimage via Wikimedia Commons

Fungal anthracnose attacks these young grapevine leaves.

Photo by CSIRO ScienceImage via Wikimedia Commons

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What is anthracnose? This fungal disease affects many plants, including vegetables, fruits, and trees. It causes dark, sunken lesions on leaves, stems, flowers, and fruits. It also attacks developing shoots and expanding leaves. It can spread very quickly during rainy seasons.

Anthracnose is a general term for a variety of diseases that affect plants in similar ways. Anthracnose is especially known for the damage that it can cause to trees. Anthracnose is caused by a fungus, and among vegetables, it attacks cucurbits.

Anthracnose can survive on infected plant debris and is very easily spread. Like rust, it thrives under moist and warm conditions and is often spread by watering.

Identification

How to Identify Anthracnose

  • On leaves, anthracnose generally appears first as small, irregular yellow or brown spots. These spots darken as they age and may also expand, covering the leaves.
  • On vegetables, it can affect any part of the plant.
  • On fruits, it produces small, dark, sunken spots, which may spread. In moist weather, pinkish spore masses form in the center of these spots. Eventually, the fruits will rot.
  • On trees, it can kill the tips of young twigs. It also attacks the young leaves, which develop brown spots and patches. It can also cause defoliation of the tree.

anthracnose-identification-disease.jpg

Photo Credit: Rutgers University. Anthracnose can affect many plants with its brown spots, including this cucumber leaf.

Control and Prevention

How to Control Anthracnose

  • Remove and destroy any infected plants in your garden. For trees, prune out the dead wood and destroy the infected leaves.
  • You can try spraying your plants with a copper-based fungicide, though be careful because copper can build up to toxic levels in the soil for earthworms and microbes. For trees, try a dormant spray of bordeaux mix.

Prevent Anthracnose

  • Plant resistant plants, or buy healthy transplants.
  • Plant your plants in well-drained soil. You can also enrich the soil with compost in order to help plants resist diseases.
  • Water your plants with a drip sprinkler, as opposed to an overhead sprinkler. Don’t touch the plants when they are wet.
  • Keep ripening fruits from touching the soil.
  • Remember to rotate your plants every 2 to 3 years.

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Do any of you use any

Do any of you use any nematode to battle bugs?

Beneficial nematodes,

Beneficial nematodes, commonly species of Steinernema and Heterorhabditis, have been used to control various insects. For example, certain species of Heterorhabditis are used to control Japanese beetle grubs in lawns. For more information, you might be interested in:
http://www.almanac.com/content/lawn-problems-and-cures

If interested in using beneficial nematodes, you’ll need to do a little research to be sure that you select the right species for the right pest, and apply them correctly, for best effect. Good luck!

Black tar spots on Laurel Oak, leaf die off

I have about 3 very large Laurel Oaks in my back yard. One oak has developed leaf die off, and now ha black tar spots on it. Recently noticed possible insect activity at base of trunk, like saw day. Very worried it's dead, and may spread to other Laurel Oaks. Any ideas?

Don't Rest on Your Laurels

Hi, Dana: The good news is that you have two healthy trees. The other news is that it is difficult to tell exactly what the problem is with the third, despite your valiant attempt at description. It would seem that this is some sort of fungal infection, either of the tree (and laurel oaks have notoriously thin bark) or roots, possibly resulting in anthracnose. The saw dust could literally be saw dust from a nonrelated insect infestation in dead wood, or it could be spores of some sort. The first option in such cases is usually to clean up both the tree (prune) and site as much as possible and keep it that way. If we were you, though, we would not waste any time in calling in a professional arborist for advice. Thanks for asking, and good luck!

confusing grammar

I think you mean you wouldn't waste any time before calling in a professional, which means to call one soon, rathern than you wouldn't waste any time in calling in a professional, which means don't call one as it would be a waste of time.

Meant to Say Before Before

Hi, Ellen: You are absolutely correct: “before” calling in a professional. Thanks for the correction!

plant pathology

it is great to share with information about plant pathology

I have white flies again. I

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.This is really exhausting. I love my plants !!TY

Hi Debra, It's hard to tell

Hi Debra,
It's hard to tell what pest you have. It could be mealy bugs. The brown "coating" on the stems may be scale insects. We suggest that you spray the soil and plants with insecticidal soap or horticultural oil. Repeat two to three times. If this doesn't help replace the potting soil with new fresh soil.
www.almanac.com/topics/gardeni...
To see more information about white flies go to http://www.almanac.com/content...
 

all my vegetables are coming

all my vegetables are coming up now,and here come the pests.my garden bean leaves are slowly getting munched,looks to me to be some sort of tiny fly.and the ants seem to have a path straight across my garden.north to south.tried the ecco friendly home defense,states its plant oils,but 98% other ingredients-not named.well it deters ants for the day,but always a new group comes through.they are different species day by day.they do not seem to be hassling the plants(cucumbers,tomato,bellpeper,lettuce,corn, and cilantro)the soil here in az is terrible,but I mixed with sand,and fertalizer.all my plants are up now from seed.marigolds is the only flower i planted and they are just starting,as i was told most pests do not come around,due to smell I assume.well enjoy everyone-may you all have a bountiful year.

Any ideas on how to get rid

Any ideas on how to get rid of slugs? I an trying to get rid of them and I cannot have big expenses on it.

they hate sand ,,,,,,put it

they hate sand ,,,,,,put it around your plants
kinserpumkinpatch@yahoo.com

I just started using cornmeal

I just started using cornmeal the snails and slugs just love it. Place the cornmeal 2TBS into a glass jar laying on it's side and wait. We have eliminated both in our yard.

Hi Rosangela, They don't like

Hi Rosangela,

They don't like beer so if you put a container close to where your endangered plants are, they will be drawn to it, crawl in and drown (but what a way to go!). Also, they don't like copper at all and you can either put copper wire around your plants in a circle or I've seen copper tape at home and garden stores that does the same thing. Both of these ways are preferable to using strong chemicals and both work well but you will need to replenish the beer periodically. You could also try a big line of salt around your plants but this is rather unsightly and will need constant tending, especially in damp or wet weather. Good luck!

Ammonia will kill slugs and

Ammonia will kill slugs and not hurt the plants. I believe the mix is 1 part to 6 water.

I have had very good results

I have had very good results using grits to get rid of fire ants. Just sprinkle the dry grits on the hills and the ants will eat them. When they take a drink of water the grits swell and burst the ants. The ants are usually gone by the next morning.

I have fire ants in my yard;

I have fire ants in my yard; but I cannot find their bed. We recently had a lot of rain; problem is this is the exact spot where I want to till the soil for a small garden in a week or so. Any suggestions on how to get rid of them?

I'm a Master Gardener in

I'm a Master Gardener in NC...this is what we recommend for organic controls...

2. Entrust®. The active ingredient in Entrust® is spinosad, which is made from spinosyn, a substance produced from the fermentation of a soil-dwelling bacterium. Entrust is very expensive but it only takes a tiny bit. For example, only 0.159 ounces of the pesticide is needed per gallon of water for a mound drench to treat fire ants. Each mound will require 1-2 gallons of the mixture depending on its size. Best results will be achieved if applied after a recent rainfall and when temperatures are between 65-85°F. Due to its high price, this product must be mail-ordered. Entrust® is used by organic growers for control of a number of vegetable pests. A one pound bag of Entrust® can retail for over $500, but this provides way more product than a single grower can use during one growing season which is why growers sometimes go in together to purchase a bag. Contains 80% active ingredient by weight.Suppliers include Johnny’s Selected Seeds and Peaceful Valley Farm Supply.View the Entrust® label.
3. Monterey Garden Insect Spray. This is another OMRI-approved spinosad product but it isonly labeled for home garden use. It is not for use on farms. This product is a liquid concentrate with 0.5% active ingredient.Suppliers include Biocontrol Network, Monterey, and Planet Natural.View the Monterey Garden Insect Spray label.4. Greenlight Fire Ant Control with Conserve. OMRI-approved spinosad product but it isonly labeled for home garden use. It is not for use on farms.
BaitsBaits are granular products that are collected as food by foraging ants. The bait granules (generally corn grit) are impregnated with oil to make them attractive to the ants as food. The ants take the bait back to the mound and feed it to the queen and the rest of the colony. According to North Carolina State University entomologist Dr. Hertl, the use of baits can reduce environmental contamination from insecticides since baits contain a very small amount of insecticide.Spinosad is the active ingredient in the organically approved baits.The best time to apply baits is in the early evening. Do not apply baits when the ground is wet as moisture can cause the oils in the bait to become rancid.Most bait products describe two options for applying the product: 1) broadcast application over a large area and 2) mound application of the bait over the mound and extending to about two feet from the mound.Mound applications are recommended because they will have the least impact on foraging native ants which directly compete with the imported fire ants. If bait is broadcast over a large area, it is likely to be ingested by foraging native ants and other insects.

Fire ant taking a bait granule back to the nest.

There are at least two organically approved spinosad baits:

1. Ferti-lome® Come and Get It! Fire Ant Killer. This product can be used on lawns and gardens, nurseries, pastures, and fruit & vegetable crops. See label for complete list of labeled use sites. Contains 0.015% active ingredient by weight.View the Ferti-lome® Come and Get It! Fire Ant Killer label. This on-line label does not have the OMRI label on it but this product is OMRI-approved and the actual bottles on the shelves now do have the OMRI label.
2. Greenlight Fire Ant Control with Conserve®. This product is labeled for use on lawns, around ornamental plants, and in home gardens (one acre or less). Contains 0.015% active ingredient by weight.These baits are available at both Pittsboro Feed and Country Farm and Home Supply in Pittsboro. Check your local farm and garden stores for supplies near you.

Spray plants with milk and

Spray plants with milk and water mixture, this works wonders!

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