Andy Wyenandt

Parsley

Septoria Leaf Spot – has been found in east Vineland this past week.

Leaf spots caused by Septoria blight are easily distinguished by small, angular to round leaf spots with grayish-brown centers with a definitive dark, brown margin. Numerous black fruiting bodies develop in the center of lesions (see VDOW). Septoria blight is spread by wind-driven rain and overhead irrigation.

Rotate applications of Quadris (azoxystrobin, 11) at 6.0 to 15.5 fl oz 2.08SC/A or Cabrio (pyraclostrobin, 11) at 12.0 to 16.0 20WG/A with Tilt (propiconazole, 3) at 3.0 to 4.0 fl oz. 3.6F/A every 7 days. A fixed copper at labeled rates can also be included if bacterial leaf spot is an issue.

Bacterial leaf spot (Pseudomonas syringae) of parsley can also show up at the same time as Septoria blight.  Leaf spots caused by Bacterial blight appear as small brown to black spots on the leaves.  The pathogen can be soil or seed borne and develops during cool, moist weather.  The disease spreads during cool, rainy weather or with overhead irrigation; and is exacerbated by high plant density.  The same control measures listed for Septoria will assist in preventing the spread of Bacterial leaf spot as long as the fixed copper is included with azoxystrobin and the fungicides are applied preventatively.  If Oxidate is used, follow the label carefully. [Read more…]

Leaf spots were reported in spinach and other greens this past week. Growers should remain diligent and scout on a regular basis. With the dry weather expected over the next week, any use of overhead irrigation will help spread potential disease. Growers should apply preventative fungicides in advance of any disease developement or use of overhead irrigation.

Rhizoctonia was found in strawberry this past week. Rhizoctonia tends to show up during dryer weather periods usually on stressed plants. In general, the longer transplants sit in the ground without getting established and putting on any new growth the more susceptible they become to pathogens such as Rhizoctonia. Abound (azoxystrobin, 11) at 6.0 to 15.5 fl oz as a foliar application, or 0.40 to 0.80 fl oz/1000 ft row has a broad label for Rhizoctonia suppression across many crops. Abound will also help control pathogens such as anthracnose fruit rot, leaf spots, and powdery mildew in strawberry.

• Cole crops
• Spinach
• Strawberry

Cole crops

Downy Mildew and Alternaria – Symptoms of downy mildew include purple to yellowish-brown spots on upper leaf surfaces. A grayish-white spore mass will develop and cover the underside of leaves under ideal temperatures (night temperatures of 46 to 61°F and day temperatures below 75°F. Downy mildew can kill young plants. Heavily infected leaves may drop providing entry points for bacterial infections (black rot and soft rot).

Symptoms of Alternaria on infected leaves include small, expanding circular lesions with concentric rings that may have a ‘shot-hole’ appearance as lesions age.  Heavily infected seedlings may result in damping-off. [Read more…]

A number of growers have reported of leaf spots appearing in spinach and other greens. Alternaria and Cladosporium leaf spots have been identified in fields in our region. Fields should be scouted on a regular basis to find ‘hot spots’. [Read more…]