First Report of Embellisia hyacinthi Causing a Leaf Spot and Bulb Skin Spot Disease on Scilla peruviana in California.

The genus Scilla (Hyacinthaceae) includes more than 50 species of perennial, flowering bulbs grown in landscapes worldwide. In December 2000 and May 2009, an unknown leaf spot disease on Scilla peruviana was submitted to the California Department of Food and Agriculture Plant Pest Diagnostic Lab. Samples were collected during routine phytosanitary inspections of production fields in Santa Cruz County in 2000 and Monterey County in 2009.

Phoma Basal Rot of Romaine Lettuce in California Caused by Phoma exigua: Occurrence, Characterization, and Control.

Beginning in 2000 and continuing into 2004, a previously undescribed disease caused significant damage to romaine lettuce (Lactuca sativa) in the coastal Salinas Valley of California. Symptoms were brownish black, sunken cavities on the crown and upper taproot. Cavities were firm, lacked signs of fungal growth, and resulted in cracking and weakening of the crown.

First Report of Ramularia carthami, Causal Agent of Ramularia Leaf Spot of Safflower, in California.

Ramularia leaf spot was identified in several fields of safflower (Carthamus tinctorius) near Gridley, CA in June 2005. Numerous circular to irregularly shaped brown lesions, 3 to 10 mm in diameter, on both sides of leaves and flower bracts resulted in stunted plants and reduced seed production. In two of the fields, nearly all plants were affected, yields were severely reduced, and the crops were abandoned.

Downy Mildew Caused by Peronospora radii on Marguerite Daisy (Argyranthemum frutescens) in California.

In California, marguerite daisy (Argyranthemum frutescens [= Chyrsanthemum frutescens]) is an important, commercially grown, perennial flowering plant that is used as a potted plant, cutflower, and landscape plant. For two seasons (2003 and 2004), a downy mildew disease has been affecting marguerite daisy at wholesale container and field cutflower nurseries and retail nurseries in coastal California (Monterey, Santa Cruz, and San Mateo counties). The disease occurred early in the season (January) and continued to infect new foliage throughout the year whenever cool, foggy weather occurred.