Poinsettias - Leaf Malformation

Greenhouse Crops
Information provided on the greenhouse crop poinsettias and the possible causes of poinsettia leaf malformation. The Oregon State University affiliated author briefly discusses several possible causes which include chemical, disease, heat stress, water stress, and nutrient deficiencies.

Getting to the Root (and Corm) of Cyclamen Diseases

Greenhouse Crops
An informative discussion about common Cyclamen diseases. The author addresses Botrytis, Pythium, Thielaviopsis, Rhizoctonia, Fusarium, and Erwinia. Descriptions of pathogen symptoms and signs are provided along with possible control options.

Maintaining Disease-Free Geranium Stock Plants...The Impossible Dream?

Greenhouse Crops
The Oregon State University affiliated author discusses methods and practices used to reduce or eliminate disease in geranium stock plants. Common geranium pathogens include Botrytis, Pythium, Rhizoctonia, Thielaviopsis, Xanthomonas, and Verticillium wilt.

Aphids in Greenhouse Crops

The most common aphid species causing problems in greenhouse crops are the green peach aphid (Myzus persicae), melon/cotton aphid (Aphis gossypii), chrysanthemum aphid (Macrosiphoniella sanbomi), rose aphid (Macrosiphum rosae), potato aphid (M. euphorbiae), and the leaf-curling plum aphid (Brachycaudus helichrysi).

Greenhouse Management of Western Flower Thrips and Tomato Spotted Wilt Virus

Greenhouse Crops
The Western flower thrip (Frankliniella occidentalis), a vector of tomato spotted wilt virus, is discussed. Information is provided on the following topics; the virus, thrips identification and lifecycle, management, barriers, monitor, chemical controls, and sanitation.

1987-1988 Research Support From Oregon Horticultural Organizations

Report on research funding from Oregon horticultural organizations for 1987-1988. The Oregon State University Horticulture Department affiliated author lists which associations and commissions funded projects and how much was received.

Pesticide Use and Disposal

Due to increased interest, information was provided for growers concerning safe pesticide use and disposal. The topics of discussion include disposal of empty pesticide containers, disposal of pesticides, and cleaning equipment.

ELISA Tests for Detection of Phytophthora

Plant Disease
Report on experiments conducted on the use of ELISA for detection of Phytophthora. The University of California, Davis affiliated authors address the reliability of ELISA for the detection of Phytophthora and several other diseases. They also discuss the future of their research involving ELISA and disease detection.

Toxicity of Growing Medium Drench Fungicides

The Ohio State University affiliated author discusses growing medium fungicide drenches and phytotoxicity. The discussion was prompted by reports of growers having issues with stunting and leaf burning after a fungicide drench of growing medium was applied.

Cold Injury During Dormancy

Plant Stress
Information provided on cold injury occurring during dormancy. Specific topics addressed include; the effects of freeze damage, cold tolerance between plant tissues, winter sun scald, frost cankers or bark splitting, and winter drying of evergreen foliage.