Connecticut State The Connecticut Agricultural Experiment Station

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 What’s New

--Updates, Alerts, and News from the PDIO--

December 2024

New Fact Sheet Published Online – Bacterial Leaf Scorch of Shade Trees

the first page of the fact sheet of bacterial leaf scorch of shade trees

Bacterial Leaf Scorch is a vascular disease capable of infecting a wide range of hosts, caused by the bacterium, Xylella fastidiosa. In October, the Plant Disease Information Office used an enzyme-linked immunosorbent assay (ELISA) to test for this disease on several samples received from local areas. Only one sample tested positive, a young swamp white oak tree in a landscape setting in Westchester County, NY. A new fact sheet on Bacterial Leaf Scorch of Shade Trees is available here.

 
June 2024

White Pine - Brown Spot Needle Blight

three photos of white pine trees infected with brown spot needle blight

Figure 1. Browning of needles.        Figure 2. Green new growth.       Figure 3. Black fungal fruiting bodies. 
We have received numerous phone calls, email, and physical samples from state residents and tree care professionals concerning about browning of needles and early defoliation of white pine trees (Figure 1). New growth of affected trees appears green and normal although old needles turn brown (Figure 2). Microscopical examinations indicate brown spot needle blight (Figure 3) is a major contributor to the early defoliation of white pine tree in early summer.  For more details of this fungal disease, please read the linked fact sheet Brown Spot Needle Blight authored by Dr. Nicholas Brazee at UMass. 
 
May 2024

Leaf Spot on Ornamental Trees and Shrubs

fungal leaf spots on hydrangea, rose, and maple leaves, respectively

 Cercospora leaf spot of hydrangea           Black spot of rose                    Anthracnose of maple

The Plant Disease Information Office has received several plant samples recently showing symptoms of different fungal leaf spot diseases on a variety of host plants. Wet spring weather conditions increase the chance of new infection as leaf surfaces remain wet for a long period of time. For more information on leaf spot diseases on woody plants, please see our fact sheet Leaf Spot Diseases of Ornamental Trees and Shrubs.

New Fact Sheets Published Online
the first page of the fact sheet of hydrangea      the first page of strawberry powdery mildew fact sheet

Powdery mildew of woody ornamentals              Powdery mildew of strawberry

 

April 2024

Black Knot on Plum and Cherry 

 

Are you seeing charcoal like swellings on the twigs of ornamental or fruiting cherry and plums? Recently, the Plant Disease Information Office has received several inquiries displaying what is known as black knot, a fungal disease of woody plants in the Prunus genus. For more information on this disease and management recommendations, you may follow this link to our fact sheet Black Knot of Ornamental Plum and Cherry.

 black knows on plum and cherry trees

 
February 2024

New Fact Sheets Posted Online

the first page of edema fact sheet                         the first page of the fact sheet black root of ornamentals

                 Edema                                          Black root rot of ornamentals