December 8, 1993

Needle Diseases of Conifers

A number of Austrian pine samples have been submitted to thePlant Disease Clinic recently showing Dothistroma needle blight,Diplodia tip blight, or both diseases. Theses diseases are acommon problems on Austrian pine and are fairly easy to recognize.

Dothistroma needle blight, which occurs primarily on Austrian,ponderosa, and mugo pines in Iowa usually occurs first on lowerbranches. Infected needles show yellow to reddish-brown spots orbands that extend around the needles. Needles die from the bandedarea to the tip. Diseased needles drop prematurely.

Do You Believe Poinsettias Are Poisonous?

This question was asked of 1000 Americans by the Society of American Florists in 1993. The answer, 53% believed incorrectly that the plant is poisonous to humans and animals. Another surprising answer, 52% of the floral clerks surveyed also believed that poinsettias are poisonous.