Plant Diseases

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Split Tomato Stem

Tomato stalks are brittle vines and split easily in strong winds, under the weight of a heavy crop or when brushed against, hence the custom of supporting and protecting plants with stakes and wire cages. In addition, the stalkäó»s tough outer surface, or epidermis, is made thicker by hairy bumps, adventitious roots that sprout near soil or during periods of drought or high humidity. If plants receive a sudden downpour after a long dry spell, the xylem, which carries water to the plant, swells, occasionally bursting the epidermis in vertical cracks. Sudden extremities in moisture and temperature can cause cracks in stalks, as well as fruits.

If you have examined the stem (without doing further damage) to eliminate a pest as the cause of this split stem, then you should just allow it to callus (heal) over and the stem should function normally to carry water & nutrients from the roots upward. Its not necessary to tape the stem, in fact it could cause moisture to accumulate inside the split area and possibly create fungal issues. If you have support higher up on the stem, it should be fine.

By | 2016-01-16T09:19:59-08:00 January 16th, 2016|Plant Diseases|0 Comments
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Rose Leaf Damage

Louisiana's warm, humid weather encourages the development of several serious diseases that can damage rose bushes. Based on the picture, it appears as though there may be more than one problem occurring on your rose. The white powdery appearing substance appears to be Powdery Mildew. You may also have black spot. The darkened areas covering the center of the leaves could be another disease process. First, timely treatment is critical, especially since multiple issues may be present. To simplify treatment, we recommend that you can take several leaf samples showing the variations of problems to a nursery for a definite diagnosis and treatment options. Also, here's a link to the Louisiana Extension Agency with more information on rose diseases and treatments for your area - http://www.lsuagcenter.com/NR/rdonlyres/FAB0070C-C6BA-405F-A150-D4086F0064C1/38087/pub2613rosediseasesHIGHRES1.pdf

Because roses in your area are susceptible to many diseases, the best cure is actually prevention. You may already be aware of some of the rose basics such as using mulch, planting where there's good drainage, avoiding overhead watering, and making sure roses get 6 or more hours of direct sunlight daily. Here's a link for general rose care for your area that may be helpful in preventing future problems - http://www.lsuagcenter.com/NR/rdonlyres/FAB0070C-C6BA-405F-A150-D4086F0064C1/38087/pub2613rosediseasesHIGHRES1.pdf

By | 2016-01-16T07:05:05-08:00 January 16th, 2016|Plant Diseases|0 Comments
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Brown Rot On Citrus

Your fruit appears to have brown rot fungus (Monilinia fructicola), a fungal disease that affects stone fruit trees, such as the plum tree. The fruit and branches of infected trees become covered in a brownish fungus that turns them sunken and soft and the fruit inedible. The flowers turn brown and sometimes excrete a brown, sticky gum. Control brown rot fungus in your plum and other stone fruit trees through manual and chemical means.

Control brown rot fungus starting in the late summer or early fall. Remove all diseased fruit that has fallen to the ground as well as fruit mummies and any cankered pieces on the tree itself. It is also beneficial to remove diseased branches in the winter when the tree is dormant. Dispose of diseased pieces immediately in a garbage container.

Prune trees to create better air circulation, which will discourage the growth of brown rot fungus. When watering plum trees, use low sprinklers that will not hit tree flowers, fruit and foliage, as this can create optimal conditions for the fungus to flourish.

Apply a synthetic fungicide or one that contains copper if you are concerned about brown rot fungus affecting your plum trees in the springtime. Follow the manufacturer's directions for exact application instructions. Spray fungicide while the trees are still in their pink bud stage for the fungicide to work best.

By | 2016-01-16T01:05:24-08:00 January 16th, 2016|Plant Diseases|0 Comments
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Bacterial Blight

Based on what we can see in the picture, this peony may have some hail damage (the small white nicks) and may also have a bacterial or fungal infection, not uncommon for peonies. It's hard to be certain without seeing the entire plant to see how many leaves are affected and where the damage is most prevalent. If you can send us a photo of the entire plant that would be helpful. In the meantime, don't overhead water, which can spread infection. Of course, it's impossible to avoid overhead watering with the rain you're experiencing now but peonies do best without overhead watering when possible. Also, remove all leaf debris that may have fallen off and discard it in the garbage, not the compost pile. If you want to remove the most infected leaves now, make sure to wipe your garden sheers off with alcohol wipes between cuts as precaution. When plants are stressed, it's best not to fertilize them, which can stress them further. Send us another photo of the entire plant and we'll try to narrow down the possibilities. You can send multiple images. Kudos to you for paying close attention to your plants!

By | 2017-09-11T15:49:27-07:00 January 15th, 2016|Plant Diseases|0 Comments
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Septoria Leaf Spot

This appears to be Septoria leaf spot. :eaf spot flourishes in damp or humid air and frequently splashing the foliage with water will encourage this fungus to get established. Water at the bottom of the plant, never on the leaves. We see it in many gardens this year, mostly on peppers and tomatoes. First, remove all the affected leaves and place in the trash not the compost pile. Next year rotate your tomatoes because the fungus will over winter in the garden for a season and would affect next years crop. This is specific to tomatoes not cucumber or the like. Good air circulation is very important when planting. Sterilize all your garden equipment that comes in contact with the tomatoes so it doesn't spread. Mulch your tomatoes if you haven't already. It keeps the spores from splashing on the ground and spreading the disease. 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. Go to your local garden center for recommendations about an organic fungicide that's labeled for septoria leaf spot. Apply at 7 to 10 day intervals throughout the season according to directions. Follow harvest restrictions listed on the pesticide label. When spraying the plants, make sure you spray the undersides of the leaf as well.

By | 2017-09-11T15:49:27-07:00 January 15th, 2016|Plant Diseases|0 Comments
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Wilting Salvia

We're not sure exactly what you're referring to as being a problem, but we're thinking you mean the plant is wilting, (its hard to tell from the perspective in the photo), so we'll address that. Salvia's require full sun all day and don't need frequent watering, especially if the soil is not well drained. Plants can wilt from too little water, or too much water. If you notice that the plant wilts during the warmest part of the day, but the soil is moist, this indicates a root decay problem, usually from over-watering. If the plant is in shade for several hours during the day and the soil is too wet, or not well drained, this could also cause root damage which would show as wilting. Is there mulch around/under the plant? Mulch is definately a good thing for gardens, but if its too close to the stems/trunck/base of the plant, it could be keeping too much moisture around the roots, again causing root rot issues. If we haven't addressed the problem you intended for us to see, please resubmit this photo, or a different one, with more info about what's concerning you and we'll try again.

By | 2016-01-15T16:40:26-08:00 January 15th, 2016|Plant Diseases|2 Comments
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Aloe Vera Color

Actually your Aloe doesn't really have a problem. Grown well (hard, tough so to speak) in full sun it should take on that coppery color. Grown in more shade the plant will become very green and somewhat not as hardy. The black spotting is likely from the full sun and not getting enough water. You can see how far down the plant is sitting in the pot? I would recommend just gently slipping the whole plant and soil out of the pot in one piece, and filling up the pot with about 2-3" of well draining potting soil (whatever would bring the plant root ball up to almost the rim) and slip the whole plant back in. You will probably need some new soil to tuck in around the sides of the old root ball as well. Give it a good thorough drink. This new and added volume of soil should help in keeping more moisture to the plant in full sun. The black spots you have won't go away, but those leaves will eventually die and be replaced with new healthy ones. Always water thoroughly when you do, and don't water again until the soil has dried out down about an inch or so into the soil - stick your finger in, roughly the distance up to your first knuckle.

By | 2016-01-14T05:07:00-08:00 January 14th, 2016|Plant Diseases|0 Comments
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Leaf Fungus On Rudbeckia

This looks like a fungal problem on your Rudbeckia. There are several fungi that can cause the leaves to be spotted or all brown, and without culturing in a lab it's impossible to know which one you have, but the cause and treatment are the same. 1. The most common cause of leaf fungi on Rudbeckia is the splashing of water on the leaves. This might be from frequent hand watering, automatic irrigation, frequent rainfalls, or a combination of all of these. Be sure that Rudbeckia, a drought-tolerant plant, is only watered every 7 days. 2. Once your plants have had this problem you'll want to use one of the organic fungicides next year to help protect the foliage once the watering has been altered. Your local garden center can suggest a product but you might try sulfur, copper, Actinovate or Serenade used according to directions. Start spraying early in the summer and apply every week to ten days to prevent the foliage from being infected.
3. Be sure your Rudbeckia is watered in the AM only, not at night when it will stay wet for longer. Be sure to grow this plant in full sun - in part-shade it is more likely to stay damp and develop fungal conditions.

By | 2016-01-14T02:14:37-08:00 January 14th, 2016|Plant Diseases|0 Comments
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Shothole On Apple Tree

This looks like a fungal disease called Cercospora Leaf Spot. This is from the following website: "Circular to angular, small to large, gray or brown spots with dark margins. Some spots may drop out, leaving ragged shot-holes. The spots may be numerous and cause the leaf to turn brown and fall prematurely. Spray applications to control diseases caused by species of Cercospora are rarely, if ever, needed." And there's another similar one called Sphaceloma that is described as "Tiny, round to irregular, tan to purplish red or black spots, often with a narrow dark border. The centers may drop out giving leaves a ragged or deformed appearance. Scabby spots may appear on petioles, green stems, flowers, and fruit." Check out this website (from which we took the disease descriptions), and we recommend you get an accurate ID from the U of Illinois Extension Advisor, a Master Gardener group, or some other professional, so you can determine the best way to deal with the issue, or whether you can leave it alone.
http://web.extension.illinois.edu/forestry/publications/pdf/forest_health/UIUC_Leaf_Spot_Diseases_of_Trees.pdf

By | 2016-01-13T13:57:54-08:00 January 13th, 2016|Plant Diseases|0 Comments
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Mango Anthracnose

Anthracnose infection. Black spots appear on both young and old leaves, bloom, and fruit. On the leaves, the black spots go all the way through the tissue. On young leaves, the black spots appear along the margins causing leaf curl and leaf drop. The disease causes flowers to drop. After the flowers have fallen, the bare bloom spikes have a darkened, dirty appearance. Young fruit will become deformed and split, eventually dropping.

Applications of copper fungicides as new tissue develops and protecting the expanding tissue will prevent anthracnose infections. For infections that come following nutritional deficiencies or wounds, prevention is the only successful control. Prevention involves spraying weekly from the first appearance of the flowers until all fruit have set with copper fungicide sprays (always follow label directions). To prevent fruit infections, sprays must be applied from the time the fruit sets until mid-May to mid-June depending on variety. See "Common Diseases of Mango in Florida" at: http://edis.ifas.ufl.edu/VH048.

By | 2016-01-13T10:32:42-08:00 January 13th, 2016|Plant Diseases|0 Comments
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