Plant Diseases

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Tomato Disorders

This is probably not an infectious disease, but it is disorders caused by cultural care practices and environmental issues. We often see tomato stems and leaves curl downward after flooding of soils around the root system. This disorder is called Epinasty and is a result of ethylene production by the plant in response to the lack of air in the soil. We've all done this - let the soil get too dry and then try to make-up for it by applying extra water. This usually just creates more problems. In short, there are several visible abnormalities in leaf color, size, and curling that can all be accounted for by the inconsistency in watering that you mention. We also recommend that, if possible, you move the planter box away from the bright-colored wall, as the increased heat and light intensity reflecting off of the wall can also cause tomato plants to develop abnormally. The plants should be placed in a sunny location where they will receive 6-8 hours of full sun every day, but away from any fences or walls. From this point, continue to water for even soil moisture (do not fluctuate between very dry and very wet) and then fertilize with a complete fertilizer (you can find them in garden centers) when the plant begins to develop flowers and tomato fruits. We've included a weblink with information about tomato culture and common pests, diseases, and disorders.
http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/tomato.html

By | 2015-11-18T16:45:08-08:00 November 18th, 2015|Plant Diseases|0 Comments
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Monilina Vacciniicorymbosi

A fungus called Monilina vaccinii-corymbosi can infect blueberry fruit with a disease called mummy berry. Fruit falls on the ground and withers into shriveled-up berries that seem deceased. But it turns out those "mummies" are actually the fungal version of the fruit — undead berry corpses, if you will. The fungus overwinters in mummified fruit on the ground. The spores of the fungus come from little mushrooms on the ground and attack developing buds in the spring. Its spores prefer to develop in warm and wet conditions. If it rains for more than a day and the temperature rises above 45 degrees in early spring, mummy berry could rise again.
Mummy berry must infect blueberries twice every year to survive. In the first stage of infection, mummies sprout small mushroom-like structures called apothecia, which produce billions of spores. Wind and rain can spread spores to the developing flowers, Pscheidt said. Infected flowers turn brown and collapse.
In the second stage of infection, which happens about three weeks after the plant is first infected, new spores form on the collapsed plant tissue. Wind, rain and pollinators spread these new spores to open flowers. If you cut open the fruit, you can see spongy white fungal growth on a cross-section of the fruit.
The gardener's best defense against this ruthless fungus is to regularly pick up shriveled fruit off the bush and ground and dispose of it as soon as you first see it, Pscheidt advised. Dispose of the mummies in a hot compost pile, toss them in the dumpster or bury them more than an inch under the soil, he said. Take care to rake up fallen berries every 2-3 weeks, Pscheidt said. Rake gently because blueberry plants have shallow roots. You can also add about 2 inches of a mulch of sawdust or leaves as an extra layer of protection.
If you are battling a mummy berry apocalypse, you may want to consider starting over and planting cultivars that resist the fungus, the blueberry varieties Bluetta, Liberty, Darrow and Olympia, among others, are resistant to mummy berry and can be grown in home gardens.

By | 2015-11-18T13:51:12-08:00 November 18th, 2015|Plant Diseases|0 Comments
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Potassium Deficiency Citrus

This not an infectious disease, nor does it appear to be caused by insects that normally feed on citrus leaves; it does however look like a deficiency of Potassium and probably Iron. Potassium is one of the 3 macro-nutrients, along with Nitrogen and Phosphorous, used by plants in the greatest amounts (some say 6 macros and include Calcium, Magnesium and Sulfur as they are used in the second greatest amounts). The downward leaf-roll is characteristic of a lack of Potassium (in the absence of insects like Aphids and Leaf miner that can cause leaf curl and distortion), and the chlorosis (yellowing) of the upper leaves is caused by a lack of Iron. From your comments it is apparent you've tried fertilizers and are conscience of watering, but the symptoms we see in your photo are very characteristic of these deficiences. We've included a link for your reference (scroll down to the bottom to see Potassium), so we recommend asking your local garden center or agricultural supply store for a citrus fertilizer. Apply the fertilizer according to label directions, and time the applications according to the info in this weblink. Citrus should only be fertilized at certain times of year. As for watering - it can become difficult to apply the appropriate amounts when trees are grown in containers. It is easy to overwater if the roots have not developed enough to absorb the amount held in the soil/pot size, and easy to underwater when the tree is outgrowing the pot size. Make sure your tree is in full sun for 6-8 hours per day for maximum water uptake and movement thru the plant. Under and over watering cause roots to either dry out or rot, and become non-functional which results in insufficient nutrient uptake. Soil and water pH also impact the plants ability to take up nutrients. We recommend you make any necessary adjustments after doing a pH test of the soil when its moist and if the pH is not in the appropriate range of 6.8 -7 you will need to amend with the appropriate materials. You may also consider moving the tree to a different pot (sort of a start-over approach) with new soil.
http://www.ipm.ucdavis.edu/PMG/C107/m107bpleaftwigdis.html

By | 2015-11-18T08:31:18-08:00 November 18th, 2015|Plant Diseases|0 Comments
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Cherry Leaf Spot

It is a challenge to identify problems from a photograph, but we suspect if this is on just a few leaves, it may be cultural - lack of too much water, weather conditions. Or your tree may have cherry leaf spot, caused by the fungus Blumeriella jaapii. Cherry leaf spot targets the foliage of cherry trees but can also infect stems and fruit. Small purple spots on the tops of leaves are generally the first symptom of this fungal disease. The spots turn brown and begin to enlarge and collapse, leaving a hole in the foliage. Older leaves will yellow and drop from the branches, and the cherry tree can lose all its leaves, which weakens the fruit tree and increases its susceptibility to cold damage. Be sure to clean up all of the fallen leaves and dispose of in your garbage. Suggest you take a few sample leaves to a horticulturist at your local garden center or public botanic garden (in a baggie) to see if the problem can be confirmed in hand as well as recommended controls, if needed.

Properly timed applications of fungicide will help prevent cherry leaf spot. Start fungicide preventive sprays at the petal fall stage and repeat every seven days until harvest. Some say way until the new leaves in the spring and others to start treatment now. It would be best to confirm that this is the problem and go from there. This happens a lot in humid weather places with often with overhead watering.

You may want to get a second opinion and take a sample to your local cooperative extension for confirmation. They will also be your best source for treatment of the problem.

By | 2015-11-18T00:54:35-08:00 November 18th, 2015|Plant Diseases|0 Comments
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Euonymous Branch Demise

Your bush looks like a Euonymous, an evergreen bush common in your area, but we can't be sure without a close up of the leaves. Regardless of the type of bush it is, it clearly has suffered damage to several branches, either from mechanical injury, a disease process, or from some type of critter.

We recommend removing the dead branches as far as they extend into the base of the shrub. You'll want to closely inspect both the damaged branches and the soil around the base of the shrub to try to determine what may have caused the branches to die.

Individual branches on any plant can suffer and even die from the weight of heavy snow. Often the damage isn't seen until mid-late spring. Look for bent and splintered branches.

Also look for signs of critter damage such as nests, chewing marks on the dead branches, etc., so you can deal with the offending critter(s) before more branch damage occurs. Sometimes voles, small field mice, get into these shrubs and chew the outer layer of the branches, cutting off the water supply. They leave trails or furrows in the soil at the base of the plant. You'll want to contact your local extension agency for control information if you see critter damage. Here's a link to their website - http://extension.usu.edu/saltlake/

If you don't see evidence of the above, check the dead branches for swollen areas called galls. These are present when an insect or bacteria has entered the branch. They also cut off water supply to the branch. Here's a link to a website with more information, including pictures of galls, so you'll know what to look for - http://www.clemson.edu/extension/hgic/pests/plant_pests/shrubs/hgic2054.html
If you find galls, remove the branch, including the portion with the gall. Whatever tools you use to remove the dead branches, don't use those tools on any other plants, including this one, until you have sanitized them by wiping them with rubbing alcohol in case their is a disease process that could be spread to other plants via your pruners.

Your decision as to whether to remove just the affected branches and wait for regrowth or remove the entire shrub is somewhat based on determining the source of the damage. If it's bacterial, resulting in galls, the same infection can occur on a new similar shrub. If all of this seems overwhelming and a lot of work, you can simply remove an affected branch back to the base of the shrub and take to a local nursery or to your extension agency for a more thorough examination and suggestions on removing the entire shrub vs removing just the affected branches.

By | 2015-11-17T11:23:00-08:00 November 17th, 2015|Plant Diseases|0 Comments
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Septoria Leaf Spot

It's either early blight or one of the leaf diseases - there are two for tomatoes, Septoria (tends to be smaller spots) and bacterial spot. If the leaves start yellowing from the bottom of the plant up, that argues for early blight. Without culturing in a lab it's hard to say which it is but the treatment for the home gardener is the same:
1. Pull off the leaves that are spotted and yellow so the plant can be better monitored and some of the spores are removed.
2. Never get the foliage wet when watering. (It's amazing how many people routinely spray the leaves of plants every evening because they think that they are somehow "refreshing" the plant. This is a prescription for every leaf disease in the book.) Water deeply less often.
3. Start spraying immediately with a copper fungicide - this is an organic treatment that is a bit stronger than other organic fungicides. If the garden is right next to a pond, lake or stream, however, do not use copper as it is toxic to aquatic life. (In such cases I would use Actinovate, a natural bacteria.) Spray under the leaves and the stems too. Although the fungicide won't "cure" the problem it can protect the newer growth long enough so that tomatoes can be harvested. Next season start spraying early first using something like Actinovate or Seranade, and switching to the copper once the plant has a problem. (Do not alternate these - the copper will kill the bacteria in the other two products.)

By | 2015-11-15T04:55:31-08:00 November 15th, 2015|Plant Diseases|0 Comments
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Septoria Leaf Spot

This is Septoria leaf spot which is caused by a fungus, Septoria lycopersici. It is one of the most destructive diseases of tomato foliage and is particularly severe in areas where wet, humid weather persists for extended periods.

Integrated Pest Management Strategies

1. Remove diseased leaves. If caught early, the lower infected leaves can be removed and burned or destroyed. However, removing leaves above where fruit has formed will weaken the plant and expose fruit to sunscald. At the end of the season, collect all foliage from infected plants and dispose of or bury. Do not compost diseased plants.

2. Improve air circulation around the plants. If the plants can still be handled without breaking them, stake or cage the plants to raise them off the ground and promote faster drying of the foliage.

3. Mulch around the base of the plants. Mulching will reduce splashing soil, which may contain fungal spores associated with debris. Apply mulch after the soil has warmed.

4. Do not use overhead watering. Overhead watering facilitates infection and spreads the disease. Use a soaker hose at the base of the plant to keep the foliage dry. Water early in the day.

5. Control weeds. Nightshade and horsenettle are frequently hosts of Septoria leaf spot and should be eradicated around the garden site.

6. Use crop rotation. Next year do not plant tomatoes back in the same location where diseased tomatoes grew. Wait 1–2 years before replanting tomatoes in these areas.

7. Use fungicidal sprays. If the above measures do not control the disease, you may want to use fungicidal sprays. Fungicides will not cure infected leaves, but they will protect new leaves from becoming infected. Apply at 7 to 10 day intervals throughout the season. Apply chlorothalonil, maneb, macozeb, or a copper-based fungicide, such as Bordeaux mixture, copper hydroxide, copper sulfate, or copper oxychloride sulfate. Follow harvest restrictions listed on the pesticide label. An organic spray would be one containing Bacillus subtilis. It should be sprayed on the plant leaves every 7 days. It should be applied to the undersides of the leaves as well since that is where the fungus resides.

Organic Strategies

Strategies 1, 2, 3, 4 and 6 are strictly organic approaches. Using an appropriate organic herbicide (or removal by hand) would be viable organic approaches to Strategy 5.
There are tomato resistant varieties. Check you favorite seed catalogs for those varieties
Please get a second opinion if you don't agree.

By | 2015-11-14T06:45:36-08:00 November 14th, 2015|Plant Diseases|0 Comments
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