Anthracnose on Bunch Grapes

More rain is falling today and is expected for the next few days.  All this wet and cooler weather creates good conditions for anthracnose infections.  Anthracnose (Elsinoe ampelina) can be severe in years with heavy and consistent rainfall (like this year).  Optimal conditions for disease development are in the upper 70s F.  The spores are splashed from plant to plant by rain.  It is seen most commonly on young, succulent green shoots and leaves.  The lesions are sunken on shoots and on leaves the leaves can be distorted and have a shot-hole appearance.  A photo of the disease on a ‘Victoria Red’ cluster is below.

Severe anthracnose infection on Victoria Red grape cluster

Severe anthracnose infection on Victoria Red grape cluster

How can anthracnose be controlled?  If you are in the Deep South, not too easily, I’m afraid.  Sanitation can help (get rid of infected plant parts).  Canopy management that promotes sunlight penetration and good airflow can also help.  But likely the best way is a dormant fungicide spray or two of lime sulfur followed by subsequent fungicide applications until veraison. More in-depth information can be found here:

http://www.smallfruits.org/smallfruitsregguide/Guides/2015/BunchGrapeSprayGuide2015.pdf

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Reported Fruit Problems in Mississippi 2014

The list below illustrates the types of pathogens/problems found on fruit plants submitted to the Mississippi State University plant diagnostic lab in 2014. The general format of the list shows the common name for the disease, followed by the scientific name of the pathogen, followed by a number in parentheses that indicates the number of times this problem was diagnosed in the lab.

Apple (Malus x domestica)
• Apple Scab suspected (Venturia inaequalis) (1)
• Cedar apple rust (Gymnosporangium juniper-virginianae) (1)
• Diplodia canker (Diplodia mutila) (1)
• Fireblight (Erwinia amylovora) (1)
• Flyspeck (Schizothyrium pomi) (1)
• Phoma Leaf spot (Phoma sp.) (1)
• Russetting (Abiotic) (1)
• Sooty Blotch (Gloeodes pomigena) (1)
• Undetermined (mummified fruit ) (1)

Blackberry (Rubus sp.) ‘Arapaho’
• Abiotic (Freeze damage) (4)
• Blackberry Rust (Phragmidium violaceum) (1)
• Cane blight (Coniothyrium fuckelii) (1)

Blueberry (Vaccinium sp.)
• Abiotic (Cold injury) (1)
• Abiotic (Possibly Glyphosate) (1)
• Leaf spot (Cercospora rubi) (1)
• Leaf spot (Septoria sp.) (1)
• Fruit Spot (Exobasdium maculosum (1)
• Twig Blight ( Fusicoccum sp.) (1)

Cherry (Prunus sp.)
• Insufficient sample (Vascular disruption suspected) (1)

Fig, Common (Ficus carica)

• Diplodia canker (Diplodia sp.) (1)
• Rust (Cerotelium fici) (1)
• Undetermined fruit rot (1)

Fruit Trees (Prunus sp.)
• Black knot (Apiosporina morbosa) (1)

Grape (Vitis vinifera)
• Abiotic (Magnesium deficiency suspected) (1)
• Abiotic (Freeze injury suspected) (2)
• Black Rot (Guignardia bidwellii / Phyllosticta ampelicida) (2)

Grapefruit (Citrus x paradisi)
• Borers suspected (1)

Jujube (Ziziphus jujube)
• Leaf spot (Cercospora sp.) (1)
• Fruit injury undetermined (1)

Mayhaw (Crataegus aestivalis)
• Insect infestation (1)
• Sooty mold (1)

Peach (Prunus persica)
• Brown fruit rot (Moilinia fructicola) (2)
• Peach leaf curl (Taphrina deformans) (1)
• Root rot (Armillaria sp.) (1)
• San Jose Scale (Quadraspidiotus perniciosus) (1)

Pear (Pyrus sp.)
• Abiotic (Chemical root injury suspected) (1)
• Fireblight (Erwinia amylovora) (2)
• Phomopsis Twig Blight (Phomopsis sp.) (1)
• Quince rust (Gymnosporangium clavipes) (1)

Pecan (Carya illinoinensis)

• Abiotic (Possible Nitrogen Burn or nutritional issue) (1)

• Animal injury suspected (1)

• No pathogens (1)
• Pecan phylloxera (Phylloxera devastratrix) (2)

Plum (Prunus sp.)

• Abiotic (Sunscald suspected) (1)
• Black knot (Apiosporina morbosa) (1)

Plum (Prunus spp.) ‘Shiro’
• Bacterial spot (Xanthomonas campestris pv. pruni) (2)
• Brown rot (Monilinia fructicola) (1)
• Plum curculio (Conotrachelus nenuphar) (1)
• Scale insect (1)

Satsuma (Citrus reticulata)
• Root/Stem injury suspected (1)

See the entire list here: http://msucares.com/lab/2014list.pdf

Pecan IPM

I am giving a talk on Pecan IPM next week in Raymond, so I thought I would bring this website to your attention: http://pecan.ipmpipe.org/index.cfm

Lots of great stuff here on dealing with insects, diseases, and other pests for pecans.  The site is based out of Texas, so some of the information may not be exactly applicable to MS, but most of it is.